<!doctype html>
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<html>
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<head>
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<meta charset="utf-8">
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<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
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<title>reveal.js</title>
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<link rel="stylesheet" href="dist/reset.css">
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<link rel="stylesheet" href="dist/reveal.css">
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<link rel="stylesheet" href="dist/theme/night-custom.css">
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<!-- Theme used for syntax highlighted code -->
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<link rel="stylesheet" href="./node_modules/highlight.js/styles/atom-one-dark-reasonable.css">
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</head>
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<body>
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<div class="reveal">
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<div class="slides">
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<section>
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<h2>Web-Entwicklung</h2>
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</section>
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<section>
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<section>
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<h2>Agenda</h2>
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</section>
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<section>
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<h3>Grundlagen</h3>
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<ul>
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<li>HTML/CSS/JS</li>
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<li>HTTP-Protokoll</li>
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<li>JSON</li>
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</ul>
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</section>
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<section>
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<h3>Fortgeschrittenes</h3>
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<ul>
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<li>JavaScript</li>
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<li>Responsive Design</li>
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<li>NodeJS</li>
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<li>WebComponents / lit</li>
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<li>Datenbank</li>
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</ul>
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</section>
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<section>
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<h3>Architektur & Paradigmen</h3>
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<ul>
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<li>Funktionale Programmierung</li>
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<li>Objektorientierte Programmierung</li>
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<li>Entwurfsmuster (Singleton, Factory, Builder...)</li>
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<li>SOLID-Prinzipien</li>
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<li>Dependency Injection</li>
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<li>MVC</li>
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<li>Redux</li>
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</ul>
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</section>
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<section>
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<h3>Interessante Technologien</h3>
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<ul>
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<li>Canvas-Element</li>
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<li>CSS-Animationen</li>
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<li>WebSockets</li>
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<li>WebWorker</li>
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<li>ServiceWorker</li>
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<li>WebRTC</li>
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<li>WebGL</li>
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<li>Progressive Web Application</li>
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<li>CEF / Electron</li>
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<li>WebAssembly</li>
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</ul>
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</section>
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<section>
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<h3>Betrieb</h3>
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<ul>
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<li>Server einrichten</li>
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<li>SSL- / TLS-Zertifikate</li>
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</ul>
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</section>
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<section>
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<h3>Workflows</h3>
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<ul>
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<li>Git</li>
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<li>Test Driven Development</li>
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<li>Continuous Integration / Continuous Delivery</li>
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</ul>
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</section>
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</section>
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<section>
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<section>
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<h2>HTML</h2>
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</section>
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<section>
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<ul>
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<li>HyperText Markup Language</li>
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<li>Erste Version 1993 von Tim Berners-Lee</li>
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<li>Dokumentationsmedium</li>
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<li>Ursprünglich rein akademische Verwendung</li>
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<li>Verlinkungen der Dokumente macht sie "hyper"</li>
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</ul>
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</section>
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<section>
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<table>
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<tr><th>Version</th><th>Erscheinung</th><th>Elemente ca.</th></tr>
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<tr><td>HTML 1.0</td><td>1993</td><td>20</td></tr>
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<tr><td>HTML 2.0</td><td>1995</td><td>50</td></tr>
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<tr><td>HTML 3.2</td><td>1997</td><td>70</td></tr>
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<tr><td>HTML 4.01</td><td>1999</td><td>90</td></tr>
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<tr><td>HTML 5.0</td><td>2014</td><td>110</td></tr>
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</table>
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</section>
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<section>
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<ul>
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<li>Heute ein "lebender Standard" (Living Standard)</li>
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<li>Stetige inkrementelle Erweiterung</li>
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</ul>
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</section>
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<section>
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<h3>Grundgerüst</h3>
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<pre>
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<code class="html" data-trim data-line-numbers>
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<script type="text/template">
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<!DOCTYPE html>
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<html lang="de">
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<head>
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<meta charset="UTF-8">
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</head>
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<body>
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</body>
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</html>
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</script>
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</code>
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</pre>
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</section>
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<section>
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<h3>Beispiel</h3>
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<pre>
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<code class="html" data-trim data-line-numbers>
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<script type="text/template">
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<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8">
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<title>Title</title>
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</head>
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<body>
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<h1>Lorem Ipsum</h1>
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<div>
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<p>Lorem ipsum dolor sit amet, consectetuer adipiscing</p>
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<a href="/assets/html/simple2.html">Weitere Infos</a>
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</div>
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</body>
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</html>
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</script>
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</code>
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</pre>
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</section>
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<section>
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<h3>Beispiel</h3>
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<iframe data-src="/assets/html/simple.html"></iframe>
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</section>
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<section>
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<h3>Aufbau eines Elements</h3>
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<pre>
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<code class="html" data-trim>
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<script type="text/template">
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<span id="my-id" class="super important">Inhalt</span>
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</script>
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</code>
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</pre>
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<pre>
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<code class="html" data-trim>
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<script type="text/template">
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<!-- HTML 4.01 -->
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<input id="input" class="super important" disabled="disabled" />
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</script>
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</code>
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</pre>
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<pre>
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<code class="html" data-trim>
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<script type="text/template">
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<!-- HTML 5 -->
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<input id="input2" class="super important" disabled>
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</script>
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</code>
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</pre>
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</section>
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</section>
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<section>
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<section>
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<h2>CSS</h2>
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</section>
|
<section>
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<ul>
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<li>Cascading Style Sheet</li>
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<li>Nach größerer Verbreitung von HTML</li>
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<li>Webseiten ansprechend gestalten</li>
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</ul>
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</section>
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<section>
|
<img data-src="/assets/images/css-sucks.png">
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</section>
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<section>
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<h3>Beispiel</h3>
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<pre>
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<code class="css" data-trim data-line-numbers>
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selector [, selector, selector, ...] {
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property: value;
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}
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</code>
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</pre>
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</section>
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<section>
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<h3>Beispiel</h3>
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<pre>
|
<code class="css" data-trim data-line-numbers>
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html {
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background-color: red;
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font-size: 30px;
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}
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</code>
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</pre>
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</section>
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<section>
|
<h3>Beispiel</h3>
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<pre>
|
<code class="html" data-trim data-line-numbers>
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<script type="text/template">
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<html lang="en">
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<head>
|
...
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<style>
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html {
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background-color: red;
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font-size: 30px;
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}
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</style>
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</head>
|
<body>
|
...
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</body>
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</html>
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</script>
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</code>
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</pre>
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</section>
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<section>
|
<h3>Beispielhafte CSS-Eigenschaften</h3>
|
<ul>
|
<li>background-color: red</li>
|
<li>font-family: Georgia, serif, Arial</li>
|
<li>text-decoration: line-through underline</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Selektoren</h3>
|
<ul>
|
<li>Umfangreiche Element-Selektoren zur Anwendung der Styles</li>
|
<li>Kinder, Enkel...</li>
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<li>Geschwister, direkte Nachfolger</li>
|
<li>Attribute</li>
|
<li>Pseudoklassen</li>
|
</ul>
|
</section>
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<section>
|
<h3>Selektoren</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
#my-id /* ID */
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html, body /* Mehrfachselektion */
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div > p /* p die direkt unterhalb eines div sind */
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div p /* p die irgendwo unterhalb eines div sind */
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a:visited /* besuchte Links */
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div:hover /* divs über die man mit der Maus fährt */
|
span.important /* span mit der Klasse "important" */
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</code>
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</pre>
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</section>
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<section>
|
<h3>Layout</h3>
|
<p>Es gibt zwei grundlegende Blocktypen:</p>
|
<p><code>block</code></p>
|
<p><code>inline</code></p>
|
</section>
|
<section>
|
<h3>Block</h3>
|
<p>Beansprucht eine ganze Zeile und verursacht Zeilenumbrüche</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
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display: block;
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</code>
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</pre>
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</section>
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<section>
|
<p>Kann Breite und Höhe haben</p>
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<pre>
|
<code class="css" data-trim data-line-numbers>
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display: block;
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width: 20px;
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height: 20px;
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</code>
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</pre>
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</section>
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<section>
|
<h3>Inline</h3>
|
<p>Wie einfacher Text, der mit anderen in der gleichen Zeile stehen kann</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
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display: inline;
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</code>
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</pre>
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</section>
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<section>
|
<p>Festlegen von Breite und Höhe sind wirkungslos</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
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display: inline;
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width: 20px; /* kein Effekt */
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height: 20px; /* kein Effekt */
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</code>
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</pre>
|
</section>
|
<section>
|
<h3>Inline-Block</h3>
|
<p>Mischform von <code>inline</code> und <code>block</code></p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
display: inline-block;
|
width: 20px;
|
height: 20px;
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Spezifität</h3>
|
<p>Regeln können andere Regeln überschreiben</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<div style="display: inline-block"></div>
|
</script>
|
</code>
|
</pre>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
#id:hover { display: none }
|
|
#id { display: block }
|
|
.class.clazz { display: inline }
|
|
div { display: inline-block }
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Box Model</h3>
|
<p>Es gibt zwei Varianten des Modells:</p>
|
<p><code>content-box</code> (default)</p>
|
<p>border-box</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
box-sizing: content-box;
|
box-sizing: border-box;
|
</code>
|
</pre>
|
</section>
|
<section>
|
<img data-src="/assets/images/css-box-model.png">
|
</section>
|
<section>
|
<h3>Beispiel</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
div {
|
border: 3px solid red;
|
padding: 10px;
|
width: 100px;
|
}
|
|
.border-box {
|
box-sizing: border-box;
|
}
|
|
.content-box {
|
box-sizing: content-box;
|
}
|
</code>
|
</pre>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<div class="content-box">content-box</div>
|
<div class="border-box">border-box</div>
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Beispiel</h3>
|
<iframe data-src="/assets/html/box-sizing.html"></iframe>
|
</section>
|
<section>
|
<h3>Positioning</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
/* default, da wo es in der Seite steht */
|
position: static;
|
/* relativ zu seiner eigentlichen Position */
|
position: relative;
|
/* relativ zu seinem nächsten non-static parent o. window */
|
position: absolute;
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
position: relative;
|
position: absolute;
|
</code>
|
</pre>
|
<p>erlauben Verschiebung mittels</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
top: 10px;
|
left: 10px;
|
right: 10px;
|
bottom: 10px;
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Beispiel Menü</h3>
|
<iframe data-src="/assets/html/css-menu.html"></iframe>
|
</section>
|
<section>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
.menu-item {
|
display: inline-block;
|
|
position: relative;
|
}
|
|
.menu-item .children {
|
display: none;
|
|
position: absolute;
|
}
|
|
.menu-item:hover .children {
|
display: block;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<div class="menu">
|
<div class="menu-item">Eins</div>
|
<div class="menu-item">
|
Hover Me!
|
<div class="children">
|
<div>Item 1</div>
|
<div>Item 2</div>
|
</div>
|
</div>
|
<div class="menu-item">Drei</div>
|
</div>
|
</script>
|
</code>
|
</pre>
|
</section>
|
</section>
|
<section>
|
<section>
|
<h2>JS</h2>
|
</section>
|
<section>
|
<ul>
|
<li>JavaScript stammt aus dem Jahr 1995 von Netscape</li>
|
<li>Syntaktisch an Java angelehnt</li>
|
<li>Ursprünglich nur optionale, verzichtbare Effekte (unobstrusive)</li>
|
<li>Mittlerweile von ECMA standardisiert</li>
|
</ul>
|
</section>
|
<section>
|
<table>
|
<tr><th>Version</th><th>ECMA Standard</th><th>Jahr</th></tr>
|
<tr><td>ES1</td><td>ECMAScript 1</td><td>1997</td></tr>
|
<tr><td>ES2</td><td>ECMAScript 2</td><td>1998</td></tr>
|
<tr><td><strong>ES3</strong></td><td><strong>ECMAScript 3</strong></td><td><strong>1999</strong></td></tr>
|
<tr><td><strong>ES5</strong></td><td><strong>ECMAScript 5</strong></td><td><strong>2009</strong></td></tr>
|
<tr><td>ES6</td><td>ECMAScript 2015</td><td>2015</td></tr>
|
<tr><td></td><td>...</td><td></td></tr>
|
<tr><td></td><td>ECMAScript 2020</td><td>2020</td></tr>
|
</table>
|
</section>
|
<section>
|
<p>Code wird zwischen <code>script</code>-Tags geschrieben</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<!DOCTYPE html>
|
<html lang="de">
|
<head>
|
<meta charset="UTF-8">
|
</head>
|
<body>
|
<script>// code</script>
|
</body>
|
</html>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>DOM-API</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
// findet das erste Element
|
const parent = document.querySelector("#id");
|
|
// findet alle Elemente
|
const elements = document.querySelectorAll("#id");
|
|
// Element erstellen
|
const newElement = document.createElement("div");
|
|
newElement.addEventListener("click", (event) => {
|
// Click-Event
|
});
|
|
// Element anhängen
|
parent.appendChild(newElement);
|
|
newElement.remove();
|
</code>
|
</pre>
|
</section>
|
</section>
|
<section>
|
<section>
|
<h2>Auslagern in verschiedene Dateien</h2>
|
</section>
|
<section>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<!DOCTYPE html>
|
<html>
|
<head>
|
<!-- CSS -->
|
<link href="styles.css" rel="stylesheet">
|
</head>
|
<body>
|
<!-- JS -->
|
<script src="index.js"></script>
|
</body>
|
</html>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Parsen eines HTML-Dokuments</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers="1|2|3|4|5|6|7|8|9|10">
|
<script type="text/template">
|
<!DOCTYPE html>
|
<html lang="de">
|
<head>
|
<meta charset="UTF-8">
|
<title>Coole Seite 😀</title>
|
</head>
|
<body>
|
<div>Ganz langer Text</div>
|
</body>
|
</html>
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Verschiedene Varianten, JavaScript erst am Ende auszuführen</p>
|
<p>Damals mit jQuery:</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<!DOCTYPE html>
|
<html>
|
<head>
|
<script>
|
$(document).ready((event) => {
|
const element = document.querySelector("#hello");
|
});
|
</script>
|
</head>
|
<body>
|
<div id="hello">Hello World!</div>
|
</body>
|
</html>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p><code>script</code>-Tag am Ende</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<!DOCTYPE html>
|
<html>
|
<head>
|
</head>
|
<body>
|
<div>Hello World!</div>
|
...
|
<script src="index.js"></script>
|
</body>
|
</html>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Event-basiert, z.B. per DOMContentLoaded</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<!DOCTYPE html>
|
<html>
|
<head>
|
<script>
|
document.addEventListener("DOMContentLoaded", (event) => {
|
// wird ausgeführt, sobald das Dokument geparst wurde
|
const element = document.querySelector("#hello");
|
});
|
</script>
|
</head>
|
<body>
|
<div id="hello">Hello World!</div>
|
</body>
|
</html>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Moderne Variante</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script src="index.js" defer></script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h2><code>document</code>-Operationen</h2>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
document.open();
|
document.write("<div>Booo!</div>");
|
document.close();
|
</code>
|
</pre>
|
</section>
|
<section>
|
<a href="https://developer.mozilla.org/en-US/docs/Web/API/Document/write">
|
<img data-src="/assets/images/document.write.jpg">
|
</a>
|
</section>
|
<section>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<body>
|
<script>document.write("<p>Dies ist ein Text.</p>")</script>
|
<button>Dunkle Magie</button>
|
<script>
|
const button = document.querySelector("button");
|
|
button.addEventListener("click", () => {
|
document.write("Und pfutsch!");
|
});
|
</script>
|
</body>
|
</code>
|
</pre>
|
</section>
|
</section>
|
<section>
|
<section>
|
<h2>HTTP-Protokoll</h2>
|
</section>
|
<section>
|
<img data-src="/assets/images/osi-model.jpg">
|
</section>
|
<section>
|
<ul>
|
<li>OSI-Schichten 5, 6 und 7</li>
|
<li>Anfrage-Antwort-Prinzip</li>
|
<li>Basiert auf einfachem Text</li>
|
</ul>
|
</section>
|
<section>
|
<table>
|
<tr><th>Version</th><th>Jahr</th></tr>
|
<tr><th>0.9</th><th>1991</th></tr>
|
<tr><th>1.0</th><th>1996</th></tr>
|
<tr><th>1.1</th><th>1999</th></tr>
|
<tr><th>2.0</th><th>2015</th></tr>
|
<tr><th>3.0</th><th>2022</th></tr>
|
</table>
|
</section>
|
<section>
|
<p>Request an www.google.de</p>
|
<pre>
|
<code class="http" data-trim data-line-numbers>
|
GET / HTTP/1.1
|
Host: www.google.de
|
User-Agent: curl/7.88.1
|
Accept: */*
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Response von www.google.de</p>
|
<pre>
|
<code class="http" data-trim data-line-numbers>
|
HTTP/1.1 200 OK
|
Date: Tue, 04 Apr 2023 15:45:26 GMT
|
Expires: -1
|
Cache-Control: private, max-age=0
|
Content-Type: text/html; charset=ISO-8859-1
|
Content-Security-Policy-Report-Only: [...]
|
Server: gws
|
X-XSS-Protection: 0
|
X-Frame-Options: SAMEORIGIN
|
Set-Cookie: [...]
|
Accept-Ranges: none
|
Vary: Accept-Encoding
|
Transfer-Encoding: chunked
|
|
<!doctype html><html>...</html>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Einfach mal testen:</p>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
curl -v --http1.0 http://www.google.de
|
curl -v --http1.1 http://www.google.de
|
curl -v --http2 http://www.google.de
|
curl -v --http2-prior-knowledge http://www.google.de
|
curl -v --http3 http://www.google.de
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Verschiedene "Verben" bzw. "Methoden"</p>
|
<ul>
|
<li>GET</li>
|
<li>POST</li>
|
<li>PUT</li>
|
<li>PATCH</li>
|
<li>DELETE</li>
|
<li>...</li>
|
</ul>
|
</section>
|
<section>
|
<p>Beispiel:</p>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
git clone https://git.furnco.de/r/public/web-development/examples.git
|
cd examples/templates/005-http-rest
|
node index.js
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="text" data-trim data-line-numbers>
|
curl -X GET -is http://localhost:3000/todo
|
curl -X POST -H "Content-Type: application/json" -d '{"name": "Einkaufen"}' -is http://localhost:3000/todo
|
curl -X POST -H "Content-Type: application/json" -d '{"name": "Putzen"}' -is http://localhost:3000/todo
|
curl -X PUT -H "Content-Type: application/json" -d '{"name": "Schlafen"}' -is http://localhost:3000/todo/1
|
curl -X DELETE -is http://localhost:3000/todo/0
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="text" data-trim data-line-numbers>
|
HTTP/1.1 200 OK
|
X-Powered-By: Express
|
Content-Type: application/json; charset=utf-8
|
Content-Length: 13
|
ETag: W/"d-KMmUcQ1kigqtwzZnU+jVDkYP3Co"
|
Date: Wed, 05 Apr 2023 12:05:05 GMT
|
Connection: keep-alive
|
Keep-Alive: timeout=5
|
|
["Einkaufen"]
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers="">
|
app.get("/todo", (req, res) => {
|
return res.json(todos);
|
});
|
|
// [...]
|
|
app.post("/todo", (req, res) => {
|
// [...]
|
return res.json(todos);
|
// [...]
|
});
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p><code>GET</code> und <code>POST</code> auf klassischen Webseiten</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<form method="post" action="/todo">
|
<input name="todo"><button>add</button>
|
</form>
|
</code>
|
</pre>
|
<p>Beispiel:</p>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
cd examples/templates/006-http-web
|
node index.js
|
</code>
|
</pre>
|
</section>
|
</section>
|
<section>
|
<section>
|
<h3>JSON</h3>
|
</section>
|
<section>
|
<ul>
|
<li><em class="h">J</em>ava<em class="h">S</em>cript <em class="h">O</em>bject <em class="h">N</em>otation</li>
|
<li>Basiert auf reinem Text</li>
|
<li>Format zur strukturierten Speicherung von Daten</li>
|
<li>Attribute müssen immer in doppelte Anführungsstriche (<code>"</code>) gesetzt werden</li>
|
</ul>
|
</section>
|
<section>
|
<p>Definition eines einfachen Objekts in JS</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const o = {
|
x: 1,
|
y: 2
|
};
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Entsprechung in JSON</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
{
|
"x": 1,
|
"y": 2
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Mögliche Typen</p>
|
<p>
|
<ul>
|
<li>Number (bzw. Integer / Float)</li>
|
<li>Boolean</li>
|
<li>String</li>
|
<li>Array</li>
|
<li>Object</li>
|
</ul>
|
</p>
|
</section>
|
<section>
|
<p>Der äußere Container kann ein Array oder ein Object sein</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
{
|
"key": "value",
|
}
|
</code>
|
</pre>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
[
|
"foo",
|
"bar"
|
]
|
</code>
|
</pre>
|
</section>
|
</section>
|
<section>
|
<section>
|
<h2>JavaScript</h2>
|
</section>
|
<section>
|
<style>
|
table.my-table td:not(:first-child) {
|
text-align: center;
|
}
|
|
table.my-table td:not(:last-child), table.my-table th:not(:last-child) {
|
border-right: 1px solid white;
|
}
|
|
table.my-table td {
|
vertical-align: middle;
|
}
|
</style>
|
<table class="my-table">
|
<tr>
|
<th></th>
|
<th>c / c++</th>
|
<th>Java</th>
|
<th>C#</th>
|
<th>JS</th>
|
</tr>
|
<tr>
|
<td>Formale Spezifikation</td>
|
<td colspan="4" class="fragment">ja</td>
|
</tr>
|
<tr>
|
<td>Übersetzung</td>
|
<td class="fragment">Nativ kompiliert</td>
|
<td class="fragment" colspan="2">Bytecode</td>
|
<td class="fragment">Interpretiert / kompiliert (JIT)</td>
|
</tr>
|
<tr>
|
<td>Typisierung</td>
|
<td colspan="3" class="fragment">statisch</td>
|
<td class="fragment">dynamisch</td>
|
</tr>
|
<tr>
|
<td>Speicher-Management</td>
|
<td class="fragment">Manuell</td>
|
<td class="fragment" colspan="3">Garbage Collector</td>
|
</tr>
|
</table>
|
</section>
|
<section>
|
<h3>Begrifflichkeiten</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function add(x, y) {
|
return x + y;
|
}
|
|
const a = 5;
|
const b = add(a, 6);
|
const c = [];
|
</code>
|
</pre>
|
<div><span class="fragment">Operator, </span><span class="fragment">Aufruf (Call), </span><span class="fragment">Ausdruck (Expression), </span><span class="fragment">Parameter, </span><span class="fragment">Argument, </span><span class="fragment">Literal, </span></div><div><span class="fragment">Zuweisung (Assignment), </span><span class="fragment">Linke Hand (Left hand), Rechte Hand (Right hand)</span></div>
|
</section>
|
<section>
|
<h3>Vorbereiten der Beispiele (bei Bedarf)</h3>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
# im Ordner 'examples/'
|
. hooks/post-checkout
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Ausführung</h3>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
# node [Script-Datei], z.B.
|
node index.js
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Ausgaben</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
console.log("Hello World!");
|
</code>
|
</pre>
|
</section>
|
|
<section>
|
<h3>Variablen</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
// < es6
|
var x = 1;
|
|
// >= es6
|
let y = 2;
|
const z = 3;
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
var yes = false;
|
|
if (yes) {
|
var a = 1;
|
}
|
|
console.log(a);
|
</code>
|
</pre>
|
<pre class="fragment">
|
<code class="bash" data-trim data-line-numbers>
|
undefined
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
var yes = false;
|
|
if (yes) {
|
let a = 1;
|
}
|
|
console.log(a);
|
</code>
|
</pre>
|
<pre class="fragment">
|
<code class="bash" data-trim data-line-numbers>
|
ReferenceError: a is not defined
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function foo() {
|
var yes = false;
|
|
if (yes) {
|
var a = 1;
|
}
|
}
|
|
foo();
|
|
console.log(a);
|
</code>
|
</pre>
|
<pre class="fragment">
|
<code class="bash" data-trim data-line-numbers>
|
ReferenceError: a is not defined
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3><code>var</code></h3>
|
<ul>
|
<li>hat <code>function</code>-Scope</li>
|
<li>wird durch <span class="italic">hoisting</span> ("hochziehen") aus dem Block heraus an den Start der Funktion gezogen</li>
|
</ul>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
var yes = false;
|
var a;
|
|
if (yes) {
|
a = 1;
|
}
|
|
console.log(a);
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3><code>let</code>, <code>const</code></h3>
|
<ul>
|
<li>haben intuitiven Block-Scope (wie viele andere Programmiersprachen auch)</li>
|
<li>daher nur an Ort und Stelle gültig in der angegebenen Reihenfolge</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Datentypen</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
let x = 5; // Number (Integer)
|
let f = 1.25; // Number (Float)
|
let b = true; // Boolean
|
let s = "hallo"; // String
|
let a = []; // Array
|
let o = {}; // Objekt
|
let nan = NaN; // Not a Number
|
let n = null; // Null
|
let u = undefined; // Undefiniert
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Alternation</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
if (x == 1) {
|
// Code
|
}
|
else if (x == 2) {
|
// alternativer Code
|
}
|
else {
|
// Fallback
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Schleifen</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
for (let i = 0; i < 5; i++) {
|
// Code
|
}
|
</code>
|
</pre>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const a = [1, 2, 3];
|
|
for (const element of a) {
|
// Code
|
}
|
</code>
|
</pre>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
while (i == 1) {
|
// Code
|
}
|
</code>
|
</pre>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
do {
|
// Code
|
} while (i == 1)
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Arrays</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
let a = [1, 2, 3];
|
|
a.push(4);
|
a.push(5);
|
|
a.pop();
|
|
console.log(a);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
[1, 2, 3, 4]
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Objekte</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
let o = {x: 1, y: 2};
|
|
console.log(o.z);
|
|
console.log(o);
|
|
o.z = 3;
|
|
console.log(o);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
undefined
|
{ x: 1, y: 2 }
|
{ x: 1, y: 2, z: 3 }
|
</code>
|
</pre>
|
</section>
|
<section>
|
<div>Objekte funktionieren intern wie Hash-Maps</div>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
let o = {};
|
|
o.a = 1;
|
o["a"] = 1; // alternativ
|
|
o["$ !"] = 2; // so sind auch komplexe Schlüssel möglich
|
|
// o."$ !" = 2; => Syntaxfehler
|
// o.$ ! = 2; => Syntaxfehler
|
|
o[true] = 3;
|
|
console.log(Object.keys(o));
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
[ 'a', '$ !', 'true' ]
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Funktionen</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function foo() {
|
console.log("foo");
|
}
|
|
function bar(a) {
|
return a;
|
}
|
|
foo();
|
|
const a = bar(1);
|
|
console.log(a);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
foo
|
1
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
let sum = function(a, b) {
|
return a + b;
|
}
|
|
let subtract = function() {
|
console.log(arguments);
|
|
return arguments[0] - arguments[1];
|
}
|
|
console.log(sum(1, 2));
|
console.log(subtract(1, 2));
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
3
|
[Arguments] { '0': 1, '1': 2 }
|
-1
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Funktionen als Konstruktor</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function Rectangle(a, b) {
|
this.a = a;
|
this.b = b;
|
}
|
|
const r = new Rectangle(2, 3);
|
|
console.log(r.a);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
2
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Objektorientierung</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function Rectangle(a, b) {
|
this.a = a;
|
this.b = b;
|
}
|
|
// jede Funktion besitzt einen Prototypen
|
Rectangle.prototype.getArea = function() {
|
return this.a * this.b;
|
}
|
|
const r1 = new Rectangle(2, 3);
|
const r2 = new Rectangle(4, 5);
|
|
console.log(r1.getArea());
|
console.log(r2.getArea());
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
6
|
20
|
</code>
|
</pre>
|
</section>
|
<section>
|
<img data-src="/assets/images/constructor-and-its-prototype.svg">
|
</section>
|
<section>
|
<div>Dynamische Änderung des Prototypen</div>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function Rectangle(a, b) {
|
this.a = a;
|
this.b = b;
|
}
|
|
const r = new Rectangle(2, 3);
|
|
console.log(r.getArea);
|
|
Rectangle.prototype.getArea = function() {
|
return this.a * this.b;
|
}
|
|
console.log(r.getArea);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
undefined
|
[Function (anonymous)]
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
Bringe dem Array eine Methode bei, welche die Summe aller enthaltenen Zahlen zurückgibt
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const a = [1, 2, 3];
|
|
console.log(a.sum());
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
6
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Lösung</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
Array.prototype.sum = function() {
|
let sum = 0;
|
|
for (let number of this) {
|
sum += number;
|
}
|
|
return sum;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Vererbung</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers="1-13|15-18|20-29">
|
// Oberklasse
|
function Shape() {
|
}
|
|
Shape.prototype.getType = function() {
|
return "Shape";
|
}
|
|
// Unterklasse
|
function Rectangle(a, b) {
|
this.a = a;
|
this.b = b;
|
}
|
|
// Prototype der Oberklasse in die Unterklasse kopieren
|
Rectangle.prototype = Object.create(Shape.prototype);
|
// Konstruktor der Oberklasse am Prototypen durch den eigenen ersetzen
|
Rectangle.prototype.constructor = Rectangle;
|
|
const r = new Rectangle(2, 3);
|
|
console.log(r.getType());
|
|
// .getType() selber implementieren
|
Rectangle.prototype.getType = function() {
|
return "Rectangle";
|
}
|
|
console.log(r.getType());
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Shape
|
Rectangle
|
</code>
|
</pre>
|
</section>
|
<section>
|
<img data-src="/assets/images/inheritance-es5.svg">
|
</section>
|
<section>
|
<div>
|
<img width="800" height="500" data-src="/assets/images/mdn-prototype.jpg">
|
</div>
|
<p>
|
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push" style="font-size: 16px">https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push</a>
|
</p>
|
</section>
|
<section>
|
<h3>Objektorientierung in es6</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
class Rectangle {
|
constructor(a, b) {
|
this.a = a;
|
this.b = b;
|
}
|
|
getArea() {
|
return this.a * this.b;
|
}
|
}
|
|
const r = new Rectangle(2, 3);
|
|
console.log(r.getArea());
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
6
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Vererbung in es6</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers="1-6|8-16|18-27">
|
// Oberklasse
|
class Shape {
|
getType() {
|
return "Shape";
|
}
|
}
|
|
// Unterklasse erbt von Oberklasse
|
class Rectangle extends Shape {
|
constructor(a, b) {
|
super();
|
|
this.a = a;
|
this.b = b;
|
}
|
}
|
|
const r = new Rectangle(2, 3);
|
|
console.log(r.getType());
|
|
// Implementierung per Prototype weiterhin möglich, falls man so will
|
Rectangle.prototype.getType = function() {
|
return "Rectangle";
|
}
|
|
console.log(r.getType());
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Shape
|
Rectangle
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Asynchronität</h3>
|
<p>Asynchron: Es wird nicht auf die Beendigung des Befehls gewartet, sondern mit dem Programm fortgefahren. Die Vollendung des asynchronen Befehls tritt <i style="font-style: italic">irgendwann</i> in der Zukunft ein.</p>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
setTimeout(callback, time); // Ausführung nach [time] Millisekunden
|
setInterval(callback, interval); // Ausführung alle [interval] Millisekunden
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
setTimeout(function() {
|
// Code, der nach 2 Sekunden ausgeführt wird
|
console.log("zweiter");
|
}, 2000);
|
|
console.log("erster");
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
erster
|
zweiter
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Aufgabe: Schreibe ein Programm, das zwei weitere beliebige Texte mit jeweils 2 Sekunden Verzögerung von einander ausgibt, d.h.</p>
|
<p>"erster" -> 2s -> "zweiter" -> 2s -> "Text A" -> 2s -> "Text B"</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
setTimeout(function() {
|
console.log("zweiter");
|
|
// weiterer Code
|
}, 2000);
|
|
console.log("erster");
|
</code>
|
</pre>
|
</section>
|
<section>
|
Lösung: Callback-Hell oder Pyramide des Todes
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
setTimeout(function() {
|
console.log("zweiter");
|
|
setTimeout(function() {
|
console.log("Text A");
|
|
setTimeout(function() {
|
console.log("Text B");
|
|
|
}, 2000);
|
}, 2000);
|
}, 2000);
|
|
console.log("erster");
|
</code>
|
</pre>
|
</section>
|
<section>
|
Hilfsmittel: Promises
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
new Promise(function (resolve, reject) {
|
// ich bin fertig
|
resolve();
|
|
// es ist ein Fehler aufgetreten
|
reject();
|
});
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const p = new Promise(function (resolve, reject) {...});
|
const p2 = new Promise(function (resolve, reject) {...});
|
const p3 = new Promise(function (resolve, reject) {...});
|
const p4 = new Promise(function (resolve, reject) {...});
|
|
p
|
.then(function() { return p2; })
|
.then(function() { return p3; })
|
.then(function() { return p4; });
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
console.log("erster");
|
|
delay(2000)
|
.then(function () {
|
console.log("zweiter");
|
|
return delay(2000);
|
})
|
.then(function() {
|
console.log("Text A");
|
|
return delay(2000);
|
})
|
.then(function() {
|
console.log("Text B");
|
})
|
</code>
|
</pre>
|
</section>
|
<section>
|
Aufgabe: Implementiere die Funktion "delay"
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const delay = function() {
|
// implementieren
|
}
|
|
console.log("erster");
|
|
delay(2000)
|
.then(function () {
|
console.log("zweiter");
|
|
return delay(2000);
|
})
|
.then(function() {
|
console.log("Text A");
|
|
return delay(2000);
|
})
|
.then(function() {
|
console.log("Text B");
|
})
|
</code>
|
</pre>
|
</section>
|
<section>
|
Lösung:
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const delay = function(ms) {
|
return new Promise(function(resolve, reject) {
|
setTimeout(function() {
|
resolve();
|
}, ms);
|
});
|
}
|
|
console.log("erster");
|
|
delay(2000)
|
.then(function () {
|
console.log("zweiter");
|
|
return delay(2000);
|
})
|
.then(function() {
|
console.log("Text A");
|
|
return delay(2000);
|
})
|
.then(function() {
|
console.log("Text B");
|
})
|
</code>
|
</pre>
|
</section>
|
<section>
|
Rückgabewerte mit Promises
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const p = new Promise(function(resolve, reject) {
|
resolve("ok");
|
});
|
|
p.then(function(value) {
|
console.log(value);
|
});
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
ok
|
</code>
|
</pre>
|
</section>
|
<section>
|
Fehlerbehandlung mit Promises
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const p = new Promise(function(resolve, reject) {
|
reject(new Error("Fehler"));
|
});
|
|
p
|
.then(function() {
|
console.log("Ich werde nicht aufgerufen")
|
})
|
.catch(function(e) {
|
console.log(e.message);
|
});
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Fehler
|
</code>
|
</pre>
|
</section>
|
<section>
|
Datei lesen mit NodeJS
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const fs = require("fs");
|
|
fs.readFile("./hello.txt", {encoding: "utf8"}, function(error, data) {
|
console.log(data);
|
});
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Hello World!
|
</code>
|
</pre>
|
</section>
|
<section>
|
Aufgabe: "Promisifiziere" analog zu "delay" in der letzten Aufgabe den Aufruf von fs.readFile()
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const fs = require("fs");
|
|
function readFile() {
|
// implementieren
|
}
|
|
readFile("./hello.txt").then(function(content) {
|
console.log(content);
|
});
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Hello World!
|
</code>
|
</pre>
|
</section>
|
<section>
|
Lösung:
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const fs = require("fs");
|
|
function readFile(path) {
|
return new Promise(function (resolve, reject) {
|
fs.readFile(path, {encoding: "utf8"}, function(error, data) {
|
resolve(data);
|
});
|
});
|
}
|
|
readFile("./hello.txt").then(function(content) {
|
console.log(content);
|
});
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Hello World!
|
</code>
|
</pre>
|
</section>
|
<section>
|
Aufgabe: Nutze die vorherige Lösung nun für eine Promise-Kette, sodass die Inhalte der zwei Dateien "hello.txt" und "hallo.txt" nacheinander ausgegeben werden:
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Hello World!
|
|
Hallo Welt!
|
|
</code>
|
</pre>
|
</section>
|
<section>
|
Lösung:
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const fs = require("fs");
|
|
function readFile(path) {
|
return new Promise(function (resolve, reject) {
|
fs.readFile(path, {encoding: "utf8"}, function(error, data) {
|
resolve(data);
|
});
|
});
|
}
|
|
readFile("./hello.txt")
|
.then(function(content) {
|
console.log(content);
|
|
return readFile("./hallo.txt");
|
})
|
.then(function(content) {
|
console.log(content);
|
});
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Hello World!
|
|
Hallo Welt!
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Async - Await</h3>
|
<ul>
|
<li>Syntaktischer Zucker für Promises</li>
|
<li>Nutzung von <code>await</code> nur im Kontext einer <code>async</code>-Funktion möglich</li>
|
</ul>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
async function wrapper() {
|
const p = new Promise(function(resolve, reject) {
|
resolve("Hello from Promise!");
|
});
|
|
const result = await p;
|
|
console.log(result);
|
}
|
|
wrapper();
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Hello from Promise!
|
</code>
|
</pre>
|
</section>
|
<section>
|
Aufgabe: Schreibe die Lösung der vorherigen Aufgabe nach Async - Await um
|
</section>
|
<section>
|
Lösung:
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const fs = require("fs");
|
|
function readFile(path) {
|
return new Promise(function (resolve, reject) {
|
fs.readFile(path, {encoding: "utf8"}, function(error, data) {
|
resolve(data);
|
});
|
});
|
}
|
|
async function wrapper() {
|
const content1 = await readFile("./hello.txt");
|
const content2 = await readFile("./hallo.txt");
|
|
console.log(content1);
|
console.log(content2);
|
}
|
|
wrapper();
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Hello World!
|
|
Hallo Welt!
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Destructuring</h3>
|
<p>Auflösen von komplexen Strukturen</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
// Objekt destrukturieren (per Attribut-Namen)
|
const { a, b } = { a: 1, b: 2 };
|
|
console.log(a);
|
console.log(b);
|
|
// Array destrukturieren (per Position)
|
const [ c, d ] = [3, 4];
|
|
console.log(c);
|
console.log(d);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
1
|
2
|
3
|
4
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
// Bei Objekten Elemente umbenennen oder auch auslassen
|
const { a: x, b: y } = { a: 1, b: 2, c: 3 };
|
|
console.log(x);
|
console.log(y);
|
|
// Bei Arrays Elemente auslassen
|
const [ , a, b, , c] = [3, 4, 5, 6, 7, 8];
|
|
console.log(a);
|
console.log(b);
|
console.log(c);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
1
|
2
|
4
|
5
|
7
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
// Verschachteltes Destructuring
|
const {a: [, x, ] } = { a: [0, 1, 2]};
|
|
console.log(x);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
1
|
</code>
|
</pre>
|
</section>
|
<section>
|
Aufgabe: x soll die 5 enthalten
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const o = { a: [0, {b: [0, 5]}, 2]};
|
|
const { /* Destructuring-Ausdruck */ } = o;
|
|
console.log(x);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
5
|
</code>
|
</pre>
|
</section>
|
<section>
|
Lösung:
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const o = { a: [0, { b: [0, 5] }, 2]};
|
|
const { a: [, { b: [, x] }]} = o;
|
|
console.log(x);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
5
|
</code>
|
</pre>
|
</section>
|
<section>
|
Aufgabe: x soll die 3 enthalten
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const o = { a: [0, {b: [0, { c: [{ x: 5 }, { d: 3}] }]}, 2]};
|
|
const { /* Destructuring-Ausdruck */ } = o;
|
|
console.log(x);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
3
|
</code>
|
</pre>
|
</section>
|
<section>
|
Lösung:
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const o = { a: [0, {b: [0, { c: [{ x: 5 }, { d: 3}] }]}, 2]};
|
|
const { a: [, {b: [, { c: [, { d: x}] }] }] } = o;
|
|
console.log(x);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
3
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Destructuring zum parallelen Ausführen von mehreren Promises</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers="1-10|11-21">
|
const fs = require("fs");
|
|
function readFile(path) {
|
return new Promise(function (resolve, reject) {
|
fs.readFile(path, {encoding: "utf8"}, function(error, data) {
|
resolve(data);
|
});
|
});
|
}
|
|
async function wrapper() {
|
const [ content1, content2 ] = await Promise.all([
|
readFile("./hello.txt"),
|
readFile("./hallo.txt")
|
]);
|
|
console.log(content1);
|
console.log(content2);
|
}
|
|
wrapper();
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Try-Catch-Finally</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function throwError() {
|
try {
|
throw new Error("Fehler!");
|
return "Hello World!";
|
}
|
catch (e) {
|
return e.message;
|
}
|
finally {
|
console.log("Finally wird immer ausgeführt");
|
return "Finally!";
|
}
|
}
|
|
const result = throwError();
|
console.log(result);
|
</code>
|
</pre>
|
<pre class="fragment">
|
<code class="bash" data-trim data-line-numbers>
|
Finally wird immer ausgeführt
|
Finally!
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Anwendungsbeispiel für Try-Catch-Finally</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function readFromDatabase() {
|
try {
|
db.connect();
|
return db.read();
|
}
|
catch (e) {
|
console.log(e.stack);
|
return "";
|
}
|
finally {
|
if (db.open) {
|
db.close();
|
}
|
}
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Scope</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function a() {
|
const x = 5;
|
|
return function() {
|
return x * x;
|
};
|
}
|
|
const squareX = a();
|
const result = squareX();
|
|
console.log(result);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
25
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>this</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
class MyClass {
|
constructor(a) {
|
this.a = a;
|
}
|
|
getA() {
|
return this.a;
|
}
|
}
|
|
const x = new MyClass(5);
|
const y = new MyClass(10);
|
|
console.log(x.getA());
|
console.log(y.getA());
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
5
|
10
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
global.a = 5;
|
|
function foo() {
|
this.a += 10;
|
}
|
|
foo();
|
|
console.log(a);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
15
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
class MyClass {
|
/* ... */
|
setA() {
|
function f() {
|
this.a += 100;
|
}
|
f();
|
}
|
}
|
|
const x = new MyClass(5);
|
|
x.setA();
|
|
console.log(x.getA());
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
TypeError: Cannot read property 'a' of undefined
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
class MyClass {
|
/* ... */
|
setA() {
|
const me = this;
|
function f() {
|
me.a += 100;
|
}
|
f();
|
}
|
}
|
|
const x = new MyClass(5);
|
|
x.setA();
|
|
console.log(x.getA());
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
105
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Arrow-Funktionen</h3>
|
<ul>
|
<li>Kompakte Schreibweise einer normalen Funktion</li>
|
<li>Bei Einzeilern ist das <code>return</code> nicht notwendig</li>
|
<li>this-Pointer des aktuellen Kontextes wird beibehalten</li>
|
</ul>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
// Einzeiler
|
const f1 = _ => 1;
|
const f2 = () => 1;
|
const f3 = (x) => x * x;
|
const f4 = (x, y) => x + y;
|
|
// Mehrzeiler
|
const f5 = (x, y) => {
|
return x * y;
|
};
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
class MyClass {
|
/* ... */
|
setA() {
|
const f = () => {
|
this.a += 100;
|
}
|
f();
|
}
|
}
|
|
const x = new MyClass(5);
|
|
x.setA();
|
|
console.log(x.getA());
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
105
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Generator-Funktionen</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function* generator() {
|
let i = 0;
|
|
while(true) {
|
yield i;
|
i++;
|
}
|
}
|
|
const g = generator();
|
|
console.log(g.next().value);
|
console.log(g.next().value);
|
console.log(g.next().value);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
1
|
2
|
3
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Generator-Funktionen</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function* generator() {
|
yield 1;
|
yield 2;
|
yield 3;
|
}
|
|
const g = generator();
|
|
for (const i of g) {
|
console.log(i);
|
}
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
1
|
2
|
3
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Nützliche Array-Funktionen</h3>
|
</section>
|
<section>
|
Aufgabe: Schreibe ein Programm, das den Gesamtumsatz aus dem ersten Halbjahr berechnet
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const revenues = [
|
{month: 0, revenue: 1000},
|
{month: 1, revenue: 2000},
|
{month: 2, revenue: 3000},
|
{month: 3, revenue: 4000},
|
{month: 4, revenue: 5000},
|
{month: 5, revenue: 6000},
|
{month: 6, revenue: 6000},
|
{month: 7, revenue: 5000},
|
{month: 8, revenue: 4000},
|
{month: 9, revenue: 3000},
|
{month: 10, revenue: 2000},
|
{month: 11, revenue: 1000}
|
];
|
|
let totalRevenue = 0;
|
|
/* ... */
|
|
console.log(totalRevenue);
|
</code>
|
</pre>
|
</section>
|
<section>
|
Lösung
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
totalRevenue = revenues
|
.filter((revenue) => revenue.month < 6)
|
.map((revenue) => revenue.amount)
|
.reduce((sum, amount) => sum + amount, 0);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
21000
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
|
|
a.filter((e) => e > 2); // Filterung
|
a.map((e) => e * 2); // Umformung
|
a.reduce((p, e) => p + e, 0); // Zusammenrechnung / Reduzierung
|
a.some((e) => e > 5); // true wenn min. ein Element die Bedingung erfüllt
|
a.every((e) => e > 5); // true wenn alle Elemente die Bedingung erfüllen
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Map</h3>
|
<ul>
|
<li>auch als "assoziatives Array" bezeichnet</li>
|
<li>iterierbare Liste</li>
|
<li>ideal zur Assoziation von z.B. Hashes zu Objekt-Instanzen o.ä.</li>
|
<li>nutzbar ab es6 / es2015</li>
|
<li>löst herkömmliche Objekte als Hash-Map ab</li>
|
</ul>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const m = new Map();
|
|
m.set("a", 0);
|
m.set("a", 1);
|
m.set("b", 2);
|
|
m.has("c"); // => false
|
|
m.delete("b");
|
|
console.log(m.get("a")); // => 1
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
m.forEach((k, v) => console.log(k, v)) // => "a" 1 ...
|
|
for (const entry of m.entries()) {
|
console.log(entry); // => ["a", 1] ...
|
}
|
|
for (const key of m.keys()) {
|
console.log(key); // => "a" ...
|
}
|
|
for (const value of m.values()) {
|
console.log(value); // => "1" ...
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Set</h3>
|
<ul>
|
<li>enthält nur einzigartige Werte</li>
|
<li>iterierbare Liste</li>
|
<li>ideale Struktur, wenn einzelne Werte einzigartig sein sollen</li>
|
<li>nutzbar ab es6 / es2015</li>
|
<li>löst individuelle Lösungen mittels Arrays und Array.prototype.indexOf o.ä. ab</li>
|
</ul>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const s = new Set();
|
|
s.add("a");
|
s.add("a");
|
|
s.has("c"); // => false
|
|
s.delete("a");
|
|
console.log(s.size); // => 0
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
s.forEach((k, v) => console.log(k, v)) // => "a" "a" ...
|
|
for (const entry of m.entries()) {
|
console.log(entry); // => ["a", "a"] ...
|
}
|
|
for (const key of m.keys()) {
|
console.log(key); // => "a"...
|
}
|
|
for (const value of s.values()) {
|
console.log(value); // => "a" ...
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>DOM-Events</h3>
|
<ul>
|
<li>funktionale Ausführung von Code</li>
|
<li>Trigger können Klicks, Scrollen, Tastendrücke, Änderungen der Fenstergröße usw. sein</li>
|
</ul>
|
</section>
|
<section>
|
<img data-src="/assets/images/dom-events.svg">
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function doSomething(e) {
|
console.log("capture");
|
}
|
|
function click(e) {
|
console.log("bubble");
|
}
|
|
div.addEventListener("click", doSomething, true);
|
|
button.addEventListener("click", click, false /* default */);
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
capturing
|
bubble
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Aufgabe: Erweitere das vorherige Beispiel so, dass das div-Element einen weiteren Click-Handler bekommt,
|
der den Text "bubble2" anzeigt, nachdem "bubble" in der Konsole geloggt wurde.</p>
|
|
<p>Erwartete Ausgabe:</p>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
capturing
|
bubble
|
bubble2
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Lösung:</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function doSomething(e) {
|
console.log("capture");
|
}
|
|
// neu
|
function doSomething2(e) {
|
console.log("bubble2");
|
}
|
|
function click(e) {
|
console.log("bubble");
|
}
|
|
div.addEventListener("click", doSomething, true);
|
div.addEventListener("click", doSomething2, false); // neu
|
|
button.addEventListener("click", click, false /* default */);
|
</code>
|
</pre>
|
</section>
|
<section>
|
Die Bubble-Phase stoppen
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function click(e) {
|
e.stopPropagation()
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Aufgabe: Ändere das Ergebnis des vorherigen Beispiels, sodass die Bubble-Phase auf Ebene des button-Elements gestoppt wird. Was ändert sich in der Ausgabe?</p>
|
</section>
|
<section>
|
<p>Lösung:</p>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function doSomething(e) {
|
console.log("capture");
|
}
|
|
function doSomething2(e) {
|
console.log("bubble2");
|
}
|
|
function click(e) {
|
e.stopPropagation();
|
console.log("bubble");
|
}
|
|
div.addEventListener("click", doSomething, true);
|
div.addEventListener("click", doSomething2, false);
|
|
button.addEventListener("click", click, false /* default */);
|
</code>
|
</pre>
|
</section>
|
<section>
|
Events programatisch triggern:
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
button.dispatchEvent(new Event("click"));
|
</code>
|
</pre>
|
</section>
|
<section>
|
Events sind synchron:
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
doSomethingElse();
|
|
button.dispatchEvent(new Event("click"));
|
|
doAnotherThing(); // wird erst ausgeführt, wenn zuvor alle Event-Handler fertig sind
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Strings</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const empty1 = "";
|
const empty1 = '';
|
|
const s1 = 'abc';
|
const s2 = "abc";
|
|
const s3 = 'a"b"c';
|
const s4 = "a\"b\"c";
|
|
const s5 = 'a\'b\'c';
|
const s6 = "a'b'c";
|
|
const s7 = `a'b'"c"`;
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h5>Strings zusammenfügen</h5>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const age = 10;
|
|
// Konkatenation
|
const s = "My age is " + number + "!";
|
|
// Interpolation
|
const s = `My age is ${number}!`;
|
|
// => "My age is 10!"
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h5>Template Strings</h5>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function sayHello() {
|
return "Hello";
|
}
|
|
let interpolation = `${sayHello()}`;
|
|
// => "Hello"
|
|
interpolation = `5 + 5 = ${5+5}`;
|
|
// => "5 + 5 = 10"
|
</code>
|
</pre>
|
</section>
|
<section>
|
lit
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
return html`<div>hello world!</div>`
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function myTag() {
|
console.log(arguments);
|
|
// return 5;
|
// return true;
|
return "abc";
|
}
|
|
let interpolation = myTag`a ${5} b ${6} c`;
|
|
// => "abc"
|
</code>
|
</pre>
|
<pre>
|
<code class="bash" data-trim data-line-numbers>
|
Arguments(3) [Array(3), 5, 6]
|
0 : (3) ['a ', ' b ', ' c', raw: Array(3)]
|
1 : 5
|
2 : 6
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h5>Aufgabe</h5>
|
<p>Schreibe ein Tag, welches die Zahlen aus den dynamischen Ausdrücken zusammenrechnet (<code>strings.js</code>)</p>
|
</section>
|
<section>
|
<h5>Lösung</h5>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function add(parts, ...numbers) {
|
return numbers.reduce((p, c) => p + c, 0);
|
}
|
|
let sum = add`a ${5} b ${6} c`;
|
|
console.log(sum);
|
|
// => 11
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h5>Rest-Operator</h5>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
function add(...numbers) {
|
return numbers.reduce((p, c) => p + c, 0);
|
}
|
|
add(1, 2, 3); // => 6
|
</code>
|
</pre>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const o1 = {a: 1, b: 2};
|
const o2 = {x: 5, y: 6, ...o1};
|
</code>
|
</pre>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
const a1 = [4, 5, 6];
|
const a2 = [1, 2, 3, ...a1];
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Relevante Browser-APIs</h3>
|
</section>
|
<section>
|
<h5>window</h5>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
window.innerWidth; // innere Auflösung des sichtbaren Fensters
|
window.innerHeight;
|
window.outerWidth; // äußere Auflösung des Browserfensters inklusive Adresszeile usw.
|
window.outerHeight;
|
|
window.addEventListener(); // Events an das äußerste "Dach"-Element hängen
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h5>location</h5>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
location.href; // aktuelle URL
|
location.host; // aktuelle Domain, z.B. "www.google.de"
|
location.protocol; // aktuelles Protokoll, z.B. "https:"
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h5>Navigator</h5>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
navigator.language; // bevorzugte Browsersprache, z.B. "de"
|
navigator.userAgent; // z.B. "Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) [...]"
|
navigator
|
.mediaDevices
|
.getDisplayMedia(); // Fordere Erlaubis zum Streamen von Anwendungen oder Bildschirmen an
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h5>Document</h5>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
document.body; // <body>-Element der Seite
|
document.activeElement; // aktives Element der Seite, welche gerade den Fokus besitzt
|
document.cookie; // für die aktuelle Seite gesetzte Cookies
|
document.execCommand("copy"); // Texte in die Zwischenablage zu schreiben
|
document.createElement("div"); // erzeuge neues DOM-Element mit angegebenen Tag
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h5>LocalStorage</h5>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
// auf 5MB Daten pro Domain begrenzt
|
localStorage.getItem(key); // Element holen
|
localStorage.setItem(key, value); // Element setzen
|
localStorage.removeItem(key); // Element entfernen
|
</code>
|
</pre>
|
</section>
|
</section>
|
<section>
|
<section>
|
<h2>CSS</h2>
|
<img data-src="/assets/images/css-sucks.png">
|
</section>
|
<section>
|
<h3>Warum CSS?</h3>
|
<ul>
|
<li>Erhöhte Zugänglichkeit des Inhalts</li>
|
<li>Wiederverwendbarkeit</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Syntax</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
selector [, selector2, selector3, ...] {
|
property1: value;
|
property2: value;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Beispiel</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
html, body {
|
width: 100%;
|
height: 100%;
|
margin: 0;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Selektoren</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
/* Elemente */
|
html, body {...}
|
|
/* IDs */
|
#my-id {...}
|
|
/* Klassen */
|
.my-class {...}
|
|
/* Pseudo-Klassen */
|
div:hover {...}
|
|
/* Attribute */
|
div[my-attribut="abc"] {...}
|
|
/* Kombinationen */
|
div.my-class#my-id {...}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Variablen</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
html {
|
--my-background-color: #abcdef;
|
}
|
|
html div {
|
background-color: var(--my-background-color, white);
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Das <code>display</code>-Attribut</h3>
|
</section>
|
<section>
|
<p>block</p>
|
<img data-src="/assets/images/css-display-block.svg">
|
<ul>
|
<li>untereinander angeordnet</li>
|
<li>nehmen sich die volle Breite</li>
|
<li><code>width</code> und <code>height</code> möglich</li>
|
</ul>
|
</section>
|
<section>
|
<p>inline</p>
|
<img data-src="/assets/images/css-display-inline.svg">
|
<ul>
|
<li>Standard bei <code>Custom Elements</code></li>
|
<li>nur so groß wie der content</li>
|
<li><code>width</code> und <code>height</code> nicht möglich</li>
|
<li>nebeneinander angeordnet</li>
|
</ul>
|
</section>
|
<section>
|
<p>inline-block</p>
|
<img data-src="/assets/images/css-display-inline-block.svg">
|
<ul>
|
<li>Mischform von <code>block</code> und <code>inline</code></li>
|
<li>nur so groß wie der content</li>
|
<li><code>width</code> und <code>height</code> möglich</li>
|
<li>nebeneinander angeordnet</li>
|
</ul>
|
</section>
|
<section>
|
<p>none</p>
|
<img data-src="/assets/images/css-display-none.svg">
|
<ul>
|
<li>unsichtbar</li>
|
<li>Platz wird nicht länger beansprucht, so als wenn das Element nicht im DOM wäre</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Das <code>position</code>-Attribut</h3>
|
</section>
|
<section>
|
<p>static</p>
|
<img data-src="/assets/images/css-position-static.svg">
|
<ul>
|
<li>Standard</li>
|
<li>Element wird am Ort der Verankerung im HTML dargestellt</li>
|
</ul>
|
</section>
|
<section>
|
<p>relative</p>
|
<img data-src="/assets/images/css-position-relative.svg">
|
<ul>
|
<li>Verschiebung zur eigentlichen <code>static</code>-Position, z.B. mittels <code>left: 20px</code></li>
|
</ul>
|
</section>
|
<section>
|
<p>absolut</p>
|
<img data-src="/assets/images/css-position-absolute.svg">
|
<ul>
|
<li>relative Verschiebung zum nächsten nicht-<code>static</code>-Parent (sonst <code>window</code>)</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Implementiere folgendes Beispiel-Menü</p>
|
<iframe data-src="/assets/html/css-menu.html"></iframe>
|
</section>
|
<section>
|
<h3>Lösung</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
.menu-item {
|
display: inline-block;
|
|
position: relative;
|
}
|
|
.menu-item .children {
|
display: none;
|
|
position: absolute;
|
}
|
|
.menu-item:hover .children {
|
display: block;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<div class="menu">
|
<div class="menu-item">Eins</div>
|
<div class="menu-item">
|
Hover Me!
|
<div class="children">
|
<div>Item 1</div>
|
<div>Item 2</div>
|
</div>
|
</div>
|
<div class="menu-item">Drei</div>
|
</div>
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Viewport</h3>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<!DOCTYPE html>
|
<html>
|
<head>
|
<meta charset="utf-8"></meta>
|
<meta
|
name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no"
|
>
|
</head>
|
<body>
|
...
|
</body>
|
</html>
|
</code>
|
</pre>
|
<p>Ein Muss für alle responsiven Seiten</p>
|
</section>
|
<section>
|
<pre>
|
<code class="bash" data-trim data-line-numbers="">
|
npm install -g http-server
|
cd pfad/zum/projekt
|
http-server --port 8080
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Einheiten</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers="">
|
div {
|
width: 1px; /* Pixel */
|
width: 1pt; /* Points */
|
width: 1em; /* Breite des "M" in der Schriftgröße des Elements */
|
width: 1rem; /* Breite des "M" in der Schriftgröße des HTML-Elements */
|
width: 1vw; /* Prozent der View Width */
|
width: 1%; /* Prozent des Elternelements */
|
|
width: 5fr; /* Fraction (nur im CSS Grid verfügbar) */
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Größeneinheiten in einer HTML-Datei ausprobieren</p>
|
</section>
|
<section>
|
<h3>CSS Flexbox</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers="">
|
.container {
|
display: flex; /* soll ein flexibler Container sein */
|
display: inline-flex;
|
|
flex-direction: column; /* Kinder spaltenweise anordnen */
|
flex-direction: row; /* Kinder zeilenweise anordnen */
|
|
align-items: center;
|
justify-content: center;
|
|
gap: 20px; /* Abstände zwischen den Achsen */
|
}
|
|
.child {
|
flex-grow: 1; /* Anteiliger Platz, wenn mehr als nötig da ist */
|
flex-shrink: 1; /* Anteiliger Platz, wenn weniger als nötig da ist */
|
flex-basis: 20px; /* Grundlage zur Berechnung der finalen Größe */
|
order: 1; /* Erlaubt die Darstellung in anderer Reihenfolge als durch das HTML vorgegeben */
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<img data-src="/assets/images/css-flexbox-axes.drawio.svg">
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Mit CSS Flexbox rumspielen</p>
|
</section>
|
<section>
|
<h3>CSS Grid</h3>
|
</section>
|
<section>
|
<h3>Terminologie</h3>
|
<img data-src="/assets/images/css-grid-terminology.drawio.svg">
|
</section>
|
<section>
|
<pre>
|
<code class="css" data-trim data-line-numbers="">
|
.grid {
|
display: grid; /* inline-grid; */
|
|
grid-template-columns: 1fr 1fr 1fr;
|
grid-template-rows: 1fr 1fr;
|
|
gap: 5px 10px;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="html" data-trim data-line-numbers="">
|
<div class="grid">
|
<span>A</span>
|
<span>B</span>
|
<span>C</span>
|
<span>D</span>
|
<span>E</span>
|
<span>F</span>
|
</div>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<iframe data-src="/assets/html/css-grid-example-1.html"></iframe>
|
</section>
|
<section>
|
<pre>
|
<code class="css" data-trim data-line-numbers="">
|
.grid {
|
grid-template-columns: [left] 1fr [column1] 1fr [column2] 1fr [right];
|
grid-template-rows: [top] 1fr [row1] 1fr [bottom];
|
}
|
|
.a {
|
grid-column: 2 / span 2;
|
grid-row: 1;
|
}
|
|
.b {
|
grid-column: left / column2;
|
grid-row: 2;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="html" data-trim data-line-numbers="">
|
<div class="grid">
|
<span class="a">A</span>
|
<span class="b">B</span>
|
</div>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<iframe data-src="/assets/html/css-grid-example-2.html"></iframe>
|
</section>
|
<section>
|
<pre>
|
<code class="css" data-trim data-line-numbers="">
|
.grid {
|
grid-template-areas:
|
"header header header"
|
"content content content";
|
}
|
|
.a {
|
grid-area: header;
|
}
|
|
.b {
|
grid-area: 2 / 1 / 2 / 3; /* start-row / start-column / end-row / end-column */
|
/* alternativ auch Namen der Lines möglich */
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<iframe data-src="/assets/html/css-grid-example-3.html"></iframe>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Implementiere folgendes Design:</p>
|
<iframe data-src="/assets/html/css-grid-excercise.html"></iframe>
|
</section>
|
<section>
|
<h3>Lösung</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers="">
|
.grid {
|
display: grid;
|
|
grid-template-rows: 1fr 5fr 1fr;
|
|
gap: 2px;
|
|
grid-template-areas:
|
"navigation header header header"
|
"navigation content content content"
|
"footer footer footer footer"
|
}
|
|
.navigation {
|
grid-area: navigation;
|
}
|
|
.header {
|
grid-area: header;
|
}
|
|
.content {
|
grid-area: content;
|
}
|
|
.footer {
|
grid-area: footer;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="html" data-trim data-line-numbers="">
|
<div class="grid">
|
<div class="area navigation">Navigation</div>
|
<div class="area header">Header</div>
|
<div class="area content">Content</div>
|
<div class="area footer">Footer</div>
|
</div>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h4>Platzierug des Inhalts</h4>
|
<pre>
|
<code class="css" data-trim data-line-numbers="">
|
.grid {
|
align-items: center;
|
justify-items: center;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<iframe data-src="/assets/html/css-grid-example-4.html"></iframe>
|
</section>
|
<section>
|
<h3>Media Queries</h3>
|
<ul>
|
<li>"Medienabfragen"</li>
|
<li>Styles auf Basis von Eigenschaften des Ausgabemediums</li>
|
<li>Große Bildschirme, kleine Bildschirme, Printmedien...</li>
|
<li>Hinweis: Sollten immer als letztes (unten) in einem Stylesheet sein</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Syntax</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
@media screen and (min-width: 640px) and (max-width: 1024px) {
|
.navigation {
|
display: none;
|
}
|
}
|
</code>
|
</pre>
|
<p>Bedeutung: Wenn die Seite auf einem Display angezeigt wird, welches zwischen 640px und 1024px in der Breite anzeigen kann, dann blende die Navigation aus</p>
|
</section>
|
<section>
|
<h3>Werte für die Ausgabemedien (optional, Standard ist "all")</h3>
|
<ul>
|
<li>all</li>
|
<li>screen</li>
|
<li>print</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Werte für die Eigenschaften mit Typ und Erklärung (kleiner Auszug)</h3>
|
<ul>
|
<li>width (Number, Breite)</li>
|
<li>height (Number, Höhe)</li>
|
<li>orientation (portrait | landscape, Quer- oder Hochformat)</li>
|
<li>hover (none | hover, Hat Zeiger zum Hovern)</li>
|
<li>forced-colors (none | active, erzwungene Farbpalette z.B. bei Sehbehinderung)</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Entwerfe eine kleine Seite mit @media und zeige ein beliebiges Element ab einer bestimmten Höhe oder Breite an (die Größe des Displays kann dynamisch mit den Entwicklertools im Gerätesimulator geändert werden)</p>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Passe die Vorlage "media-queries-responsive-layout.html" mit @media-Queries so an, dass das Menü links ab einer maximalen Breite von 480 Pixel und kleiner nach links oben in die Ecke minimiert wird und nur per Hover wieder 50% Breite und 100% Höhe bekommt</p>
|
</section>
|
<section>
|
<img data-src="/assets/images/media-queries-excercise.png">
|
</section>
|
<section>
|
<h3>Lösung</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
@media screen and (max-width: 480px) {
|
.menu {
|
grid-area: unset;
|
|
position: absolute;
|
}
|
|
.menu:hover {
|
height: 100%;
|
width: 50%;
|
}
|
|
.grid {
|
grid-template-columns: 0fr 5fr;
|
}
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Transform</h3>
|
<ul>
|
<li>rein optisch, d.h. "physische" Größe bleibt erhalten</li>
|
<li>eine Art "Shader" auf Grafikebene</li>
|
<li>Effekte wie Drehung, Vergrößerung, Verschiebung usw.</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Syntax</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
.foo {
|
transform: translateX(20px) translateY(20px);
|
transform-origin: left;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Mögliche Effekte</h3>
|
<ul>
|
<li>translate</li>
|
<li>rotate</li>
|
<li>scale</li>
|
<li>scew</li>
|
</ul>
|
<p>Die meisten besitzen zusätzlich spezifischere X-, Y- oder 3D-Versionen</p>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Probiere die genannten Transform-Effekte in einer beliebigen Seite aus</p>
|
</section>
|
<section>
|
<h3>Transition</h3>
|
<ul>
|
<li>Elemente können "weich" verändert werden</li>
|
<li>Mögliche Attribute, deren Änderungen animiert werden können sind z.B. <code>width</code>, <code>height</code>, <code>transform</code>, <code>color</code> und viele weitere</li>
|
<li>Das Attribut <code>display</code> lässt sich jedoch nicht animieren</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Syntax</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
.foo {
|
width: 100%;
|
background-color: red;
|
/* transition: [Attribut] [Dauer] [Zeitfunktion] */
|
transition: width 1s ease-out;
|
}
|
|
.foo:hover {
|
width: 50%;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Beispiel</h3>
|
<iframe data-src="/assets/html/css-transition.html"></iframe>
|
</section>
|
<section>
|
<h3>Animation</h3>
|
<ul>
|
<li>Es können zusätzlich eigene Animationen entworfen werden</li>
|
<li>Definition per <code>Keyframes</code></li>
|
</ul>
|
</section>
|
<section>
|
<h3>Syntax</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
.foo {
|
animation-duration: 3s;
|
animation-name: slidein;
|
}
|
|
@keyframes slidein {
|
from {
|
margin-left: 100%;
|
width: 300%;
|
}
|
|
to {
|
margin-left: 0%;
|
width: 100%;
|
}
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Alternative Syntax</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
.foo {
|
/* ... */
|
}
|
|
@keyframes slidein {
|
1% {
|
margin-left: 100%;
|
}
|
|
100% {
|
margin-left: 0%;
|
}
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Beispiel</h3>
|
<iframe data-src="/assets/html/css-animation.html"></iframe>
|
</section>
|
<section>
|
<h3>3D Transform</h3>
|
<ul>
|
<li>Neben den gewohnten X- und Y-Achsen (Breite und Höhe) gibt es auch noch die Z-Achse</li>
|
<li>Bewegung entlang der Sichtachse, d.h. zum bzw. vom Betrachter weg</li>
|
<li>Perspektivische Effekte möglich</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Beispiel</h3>
|
<iframe data-src="/assets/html/css-transform-3d.html"></iframe>
|
</section>
|
<section>
|
<h3>Bedingungen / Optionen</h3>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
.container {
|
perspective: 1000px; /* "Entfernung" des Betrachters */
|
|
transform-style: preserve-3d; /* oder "flat" */
|
}
|
|
.element {
|
backface-visibility: hidden; /* oder "visible" */
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Beispiel</h3>
|
<iframe data-src="/assets/html/css-transform-3d-cube.html"></iframe>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Implementiere einen drehenden Würfel (Vorlage "templates/008-css/css-3d-cube.html")</p>
|
</section>
|
</section>
|
<section>
|
<section>
|
<h2>Web Components</h2>
|
</section>
|
<section>
|
<p>Was sind Web Components?</p>
|
<img data-src="/assets/images/web-components.svg">
|
</section>
|
<section>
|
<p>Vorteile</p>
|
<ul>
|
<li>Entwicklung eigener HTML-Elemente, welche sich nahtlos neben nativen Elementen nutzen lassen</li>
|
<li>Hohe Wiederverwendbarkeit in mehreren Projekten</li>
|
<li>Keine Libraries oder Frameworks notwendig, um eigene Elemente zu entwickeln</li>
|
<li>Kapselung des Scopes sowohl von JS (Variablen...) als auch CSS (id, class...)</li>
|
</ul>
|
</section>
|
<section>
|
<h3>Ansätze in der Vergangenheit und Alternativen heute</h3>
|
</section>
|
<section>
|
<h4>jQuery</h4>
|
<a href="https://api.jqueryui.com/accordion/#entry-examples" target="_blank">https://api.jqueryui.com/accordion/#entry-examples</a>
|
</section>
|
<section>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<div id="accordion" class="ui-accordion ui-widget ui-helper-reset" role="tablist">
|
<h3 class="ui-accordion-header ui-corner-top ui-state-default ui-accordion-icons ui-accordion-header-active ui-state-active" role="tab" id="ui-id-1" aria-controls="ui-id-2" aria-selected="true" aria-expanded="true" tabindex="0">
|
<span class="ui-accordion-header-icon ui-icon ui-icon-triangle-1-s"></span>Section 1</h3>
|
<div class="ui-accordion-content ui-corner-bottom ui-helper-reset ui-widget-content ui-accordion-content-active" id="ui-id-2" aria-labelledby="ui-id-1" role="tabpanel" aria-hidden="false" style="display: block; height: 166.8px;">
|
<p>Mauris mauris ante, blandit et, ultrices a, suscipit eget.
|
Integer ut neque. Vivamus nisi metus, molestie vel, gravida in,
|
condimentum sit amet, nunc. Nam a nibh. Donec suscipit eros.
|
Nam mi. Proin viverra leo ut odio.</p>
|
</div>
|
<h3 class="ui-accordion-header ui-corner-top ui-state-default ui-accordion-icons ui-accordion-header-collapsed ui-corner-all" role="tab" id="ui-id-3" aria-controls="ui-id-4" aria-selected="false" aria-expanded="false" tabindex="-1"><span class="ui-accordion-header-icon ui-icon ui-icon-triangle-1-e"></span>Section 2</h3>
|
<div class="ui-accordion-content ui-corner-bottom ui-helper-reset ui-widget-content" id="ui-id-4" aria-labelledby="ui-id-3" role="tabpanel" aria-hidden="true" style="display: none; height: 166.8px;">
|
<p>Sed non urna. Phasellus eu ligula. Vestibulum sit amet purus.
|
Vivamus hendrerit, dolor aliquet laoreet, mauris turpis velit,
|
faucibus interdum tellus libero ac justo.</p>
|
</div>
|
<h3 class="ui-accordion-header ui-corner-top ui-state-default ui-accordion-icons ui-accordion-header-collapsed ui-corner-all" role="tab" id="ui-id-5" aria-controls="ui-id-6" aria-selected="false" aria-expanded="false" tabindex="-1"><span class="ui-accordion-header-icon ui-icon ui-icon-triangle-1-e"></span>Section 3</h3>
|
<div class="ui-accordion-content ui-corner-bottom ui-helper-reset ui-widget-content" id="ui-id-6" aria-labelledby="ui-id-5" role="tabpanel" aria-hidden="true" style="display: none; height: 166.8px;">
|
<p>Nam enim risus, molestie et, porta ac, aliquam ac, risus.
|
Quisque lobortis.Phasellus pellentesque purus in massa.</p>
|
<ul>
|
<li>List item one</li>
|
<li>List item two</li>
|
<li>List item three</li>
|
</ul>
|
</div>
|
</div>
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h4>angular</h4>
|
<img data-src="/assets/images/web-components-angular.png">
|
</section>
|
<section>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<app-root _nghost-ng-c3715250071="" ng-version="17.0.0"><app-top-bar _ngcontent-ng-c3715250071="" _nghost-ng-c3918259376=""><a _ngcontent-ng-c3918259376="" routerlink="/" ng-reflect-router-link="/" href="/"><h1 _ngcontent-ng-c3918259376="">My Store</h1></a><a _ngcontent-ng-c3918259376="" routerlink="/cart" class="button fancy-button" ng-reflect-router-link="/cart" href="/cart"><em _ngcontent-ng-c3918259376="" class="material-icons">shopping_cart</em>Checkout
|
</a></app-top-bar><div _ngcontent-ng-c3715250071="" class="container"><router-outlet _ngcontent-ng-c3715250071=""></router-outlet><app-product-list _nghost-ng-c2837874410=""><h2 _ngcontent-ng-c2837874410="">Products</h2><div _ngcontent-ng-c2837874410=""><h3 _ngcontent-ng-c2837874410=""><a _ngcontent-ng-c2837874410="" title="Phone XL details" ng-reflect-router-link="/products,1" href="/products/1"> Phone XL </a></h3><p _ngcontent-ng-c2837874410=""> Description: A large phone with one of the best screens </p><!--bindings={
|
"ng-reflect-ng-if": "A large phone with one of the "
|
}--><button _ngcontent-ng-c2837874410="" type="button"> Share </button><app-product-alerts _ngcontent-ng-c2837874410="" _nghost-ng-c869072018="" ng-reflect-product="[object Object]"><p _ngcontent-ng-c869072018=""><button _ngcontent-ng-c869072018="" type="button">Notify Me</button></p><!--bindings={
|
"ng-reflect-ng-if": "true"
|
}--></app-product-alerts></div><div _ngcontent-ng-c2837874410=""><h3 _ngcontent-ng-c2837874410=""><a _ngcontent-ng-c2837874410="" title="Phone Mini details" ng-reflect-router-link="/products,2" href="/products/2"> Phone Mini </a></h3><p _ngcontent-ng-c2837874410=""> Description: A great phone with one of the best cameras </p><!--bindings={
|
"ng-reflect-ng-if": "A great phone with one of the "
|
}--><button _ngcontent-ng-c2837874410="" type="button"> Share </button><app-product-alerts _ngcontent-ng-c2837874410="" _nghost-ng-c869072018="" ng-reflect-product="[object Object]"><!--bindings={
|
"ng-reflect-ng-if": "false"
|
}--></app-product-alerts></div><div _ngcontent-ng-c2837874410=""><h3 _ngcontent-ng-c2837874410=""><a _ngcontent-ng-c2837874410="" title="Phone Standard details" ng-reflect-router-link="/products,3" href="/products/3"> Phone Standard </a></h3><!--bindings={
|
"ng-reflect-ng-if": ""
|
}--><button _ngcontent-ng-c2837874410="" type="button"> Share </button><app-product-alerts _ngcontent-ng-c2837874410="" _nghost-ng-c869072018="" ng-reflect-product="[object Object]"><!--bindings={
|
"ng-reflect-ng-if": "false"
|
}--></app-product-alerts></div><!--bindings={
|
"ng-reflect-ng-for-of": "[object Object],[object Object"
|
}--></app-product-list><!--container--></div>
|
</app-root>
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Aufbau einer Web Component</h3>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<!--
|
Hinweis: Der Name bzw. der Selektor muss immer einen Bindestrich enthalten,
|
damit keine Namens-Kollisionen mit nativen HTML-Tags entstehen können
|
-->
|
<hello-world></hello-world>
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers="1-16|19">
|
<script type="text/template">
|
class HelloWorldComponent extends HTMLElement {
|
constructor() {
|
super();
|
|
const shadowRoot = this.attachShadow({mode: "open"});
|
|
shadowRoot.innerHTML = `
|
<style>
|
div {
|
background-color: coral;
|
color: white;
|
}
|
</style>
|
<div>Hello World!</div>
|
`;
|
}
|
}
|
|
window.customElements.define("hello-world", HelloWorldComponent);
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<iframe data-src="/assets/html/hello-world.html"></iframe>
|
</section>
|
<section>
|
<h4>Light DOM vs Shadow DOM</h4>
|
<img data-src="/assets/images/web-components-shadow-root.png" width="500px">
|
</section>
|
<section>
|
<h4>Suche von Elementen im Light- und Shadow DOM</h4>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
<script type="text/template">
|
// Light DOM
|
const span = document.querySelector("span"); // Hi!
|
const divs = document.querySelectorAll("div");
|
|
console.log(divs.length); // => 1
|
|
// Shadow DOM
|
const helloWorld = document.querySelector("hello-world");
|
|
helloWorld.shadowRoot.querySelector("div"); // Hello World!
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Auf Attribute reagieren</h3>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<hello-world my-attribute="a"></hello-world>
|
</script>
|
</code>
|
</pre>
|
<pre>
|
<code class="js" data-trim data-line-numbers="2|8-10">
|
<script type="text/template">
|
class HelloWorldComponent extends HTMLElement {
|
static observedAttributes = ["my-attribute"];
|
|
constructor() {
|
// ...
|
}
|
|
attributeChangedCallback(name, oldValue, newValue) {
|
console.log(`${name}: changed from ${oldValue} to ${newValue}`);
|
}
|
}
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Lasse die eigene Komponente "hello-sayer" auf eine Änderung des "name"-Attributs reagieren, indem der dort eingetragene Name in der Komponente angezeigt wird (Beispiel: name="Joe" => Hello Joe!)</p>
|
<p>(/examples/templates/web-components/hello-sayer.html)</p>
|
</section>
|
<section>
|
<h3>Musterlösung</h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
<script type="text/template">
|
class HelloSayerComponent extends HTMLElement {
|
static observedAttributes = ["name"];
|
|
constructor() {
|
super();
|
|
this.root = this.attachShadow({mode: "open"});
|
|
this.root.innerHTML = `
|
<style>
|
div {
|
background-color: coral;
|
color: white;
|
}
|
</style>
|
<div>Hello!</div>
|
`;
|
}
|
|
attributeChangedCallback(name, oldValue, newValue) {
|
this.root.querySelector("div").innerHTML = `Hello ${newValue}!`;
|
}
|
}
|
|
window.customElements.define("hello-sayer", HelloSayerComponent);
|
|
const names = ["Joe", "Allie"];
|
let counter = 0;
|
|
setInterval(() => document.querySelector("hello-sayer").setAttribute("name", names[counter++ % 2]), 2000);
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<iframe data-src="/assets/html/hello-sayer.html"></iframe>
|
</section>
|
<section>
|
<h3>Elemente aus dem LightDOM platzieren mit <code><slot></code></h3>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
<script type="text/template">
|
this.root.innerHTML = `
|
<span>Hello <slot></slot>!</span>
|
`;
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h4>Beispiel</h4>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<hello-sayer>Joe</hello-sayer>
|
<hello-sayer>Allie</hello-sayer>
|
</script>
|
</code>
|
</pre>
|
<iframe data-src="/assets/html/hello-sayer-2.html"></iframe>
|
</section>
|
<section>
|
<h3>Mehrfache benannte <code><slot></code>s</h3>
|
<pre>
|
<code class=js data-trim data-line-numbers>
|
<script type="text/template">
|
this.root.innerHTML = `
|
<span>
|
first name: <slot name="first"></slot> |
|
last name: <slot name="last"></slot>
|
</span>
|
`;
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h4>Beispiel</h4>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<name-field>
|
<span slot="first">Leia</span>
|
<span slot="last">Organa</span>
|
</name-field>
|
</script>
|
</code>
|
</pre>
|
<iframe data-src="/assets/html/name-field.html"></iframe>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Entwerfe eine <code>CardComponent</code> (Vorlage "card-component.html") in folgendem Stil und nutze dabei sinnvolle <code><slot></code>s:</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<script type="text/template">
|
<card-component>
|
<span slot="title">This is a title</span>
|
<span slot="content">...Lorem ipsum dolor sit amet, consetetur sadipscing elitr...</span>
|
</card-component>
|
</script>
|
</code>
|
</pre>
|
<iframe data-src="/assets/html/exercise-card-component.html"></iframe>
|
</section>
|
<section>
|
<h3>Styling einer Web Component</h3>
|
<p>Ein <code>:host</code>-Block mit einem <code>display</code> gehört zum guten Ton!</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
<script type="text/template">
|
:host {
|
display: block; /* inline, inline-block, flex, grid etc... */
|
|
color: red;
|
|
font-family: Arial, Helvetica, sans-serif;
|
}
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Innerhalb einer Komponente können beliebige Styles für verschiedene Selektoren verwendet werden</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
<script type="text/template">
|
:host {
|
display: block;
|
}
|
|
.info {
|
background-color: lightblue;
|
}
|
|
.warning {
|
background-color: yellow;
|
}
|
</script>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Welche Wechselwirkungen haben Styles zueinander, die innerhalb und außerhalb einer Komponente definiert sind? (Vorlage "web-component-styles.html")</p>
|
</section>
|
<section>
|
<p>Einige globale Styles werden dennoch vererbt:</p>
|
<ul>
|
<li>Sämtliche Styles, die standardmäßig einen Wert von <code>inherit</code> besitzen (z.B. <code>color</code> oder <code>font-family</code>)</li>
|
<li>Eigene CSS-Variablen wie z.B. <code>--my-custom-color</code></li>
|
</ul>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Passe das vorherige Ergebnis (Vorlage "web-component-styles.html") so an, dass ein beliebiger Style per CSS-Variable von außen gesetzt werden kann (z.B. <code>color</code> oder <code>background-color</code>)</p>
|
<p>Erinnerung CSS-Variablen:</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
/* Definition */
|
html {
|
--my-variable: #abcdef;
|
}
|
|
/* Usage */
|
.my-class {
|
background-color: var(--my-variable, white);
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>In der Anfangszeit von Web Components wurde oft folgendes Muster zur Individualisierung verwendet:</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
/* Global Scope */
|
html {
|
--my-border-color: #abcdef;
|
--my-border-width: 1px;
|
--my-margin-top: 1rem;
|
--my-margin-bottom: 1rem;
|
}
|
|
/* Inside Web Component */
|
.container {
|
border-color: var(--my-border-color, white);
|
border-width: var(--my-border-width, 1px);
|
margin-top: var(--my-margin-top, 0.5rem);
|
margin-bottom: var(--my-margin-bottom, 0.5rem);
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<p>Eleganteres Stylen von Web Components mittels <code>part</code></p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
/* Global Scope */
|
my-component::part(inner) {
|
border-color: yellow;
|
border-width: 2px;
|
}
|
|
/* Inside Web Component */
|
<div part="inner"></div>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Passe die <code>CardComponent</code> aus einer vorherigen Übung an (Vorlage "card-component.html"), sodass man Titel und Inhalt einfach von außen per <code>part</code>s stylen kann.</p>
|
</section>
|
<section>
|
<p><code>part</code>s von eingebetteten Web Components exportieren und verfügbar machen</p>
|
<pre>
|
<code class="html" data-trim data-line-numbers>
|
<!-- Inner Component Html -->
|
<div part="inner">Inner Text</div>
|
|
<!-- Outer Component Html -->
|
<inner-component exportparts="inner"></inner-component>
|
|
<!-- Global Html -->
|
<outer-component></outer-component>
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Passe das Beispiel (Vorlage "exportparts.html") entsprechend an, sodass von außen sowohl der <code>Inner Text</code> als auch der <code>Outer Text</code> stylebar sind</p>
|
</section>
|
<section>
|
<h3>Stylen von LightDOM-Kindern</h3>
|
<p>Web Components können direkte Kinder, die via <code>slot</code> eingefügt werden, stylen. Hierfür gibt es den Pseudo-Elemente-Selektor <code>::slotted([selector])</code>, welcher Elemente selektiert, die in einem Slot stecken:</p>
|
<pre>
|
<code class="css" data-trim data-line-numbers>
|
/* Inside Web Component */
|
::slotted(*) { /* Selectors like elements, #id or .class */
|
font-style: italic;
|
}
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Definiere mit dem Pseudo-Elemente-Selektor <code>::slotted()</code> Styles, sodass per <code>slot</code> eingefügte Elemente mit der Klasse <code>red</code> einen roten und Elemente mit der Klasse <code>blue</code> einen blauen Hintergrund haben. Die Schriftart soll jeweils weiß sein (Vorlage "slotted.html")</p>
|
</section>
|
<section>
|
<h3>Events in Web Components</h3>
|
<img data-src="/assets/images/web-components-event-bubbling-shadow-dom.png">
|
<ul>
|
<li>Events können an einer Web Component selbst oder innerhalb des Shadow Dom <code>dispatcht</code> werden</li>
|
<li>Das Shadow Root der Komponente stellt eine Art "gläserne Decke" dar</li>
|
<li>Standard-Events der UI wie <code>click</code> bubbeln durch das Shadow Dom nach oben durch</li>
|
<li>Ein <code>CustomEvent</code> muss entsprechend konfiguriert werden</li>
|
</ul>
|
</section>
|
<section>
|
<pre>
|
<code class="js" data-trim data-line-numbers>
|
button.dispatchEvent(new CustomEvent(
|
"tabactivated", // Name des Events, frei wählbar
|
{
|
detail: "any data", // beliebige Daten wie Strings, Zahlen, Booleans usw.
|
bubbles: true, // bestimmt, ob das Event durch alle Eltern nach oben steigt
|
cancelable: true, // Abbrechbar per event.preventDefault()
|
composed: true // durch eventuelle Shadow Root steigen, falls vorhanden.
|
}
|
));
|
</code>
|
</pre>
|
</section>
|
<section>
|
<h3>Aufgabe</h3>
|
<p>Entwickle eine Tab-Komponente (Vorlage "tab-componenmt.html"), welche beim Click auf einen Registerreite / Tab ein Event feurt, welches die Außenwelt über das gerade aktivierte Tab (tab-id) informiert</p>
|
</section>
|
</section>
|
</div>
|
</div>
|
|
<script src="dist/reveal.js"></script>
|
<script src="plugin/notes/notes.js"></script>
|
<script src="plugin/markdown/markdown.js"></script>
|
<script src="plugin/highlight/highlight.js"></script>
|
<script>
|
// More info about initialization & config:
|
// - https://revealjs.com/initialization/
|
// - https://revealjs.com/config/
|
Reveal.initialize({
|
hash: true,
|
slideNumber: "c/t",
|
transition: "fade",
|
|
// Learn about plugins: https://revealjs.com/plugins/
|
plugins: [ RevealMarkdown, RevealHighlight, RevealNotes ]
|
});
|
</script>
|
</body>
|
</html>
|
