public/web-development/presentation.git

			@@ -8,16 +8,1794 @@

			<link rel="stylesheet" href="dist/reset.css">
			<link rel="stylesheet" href="dist/reveal.css">
			<link rel="stylesheet" href="dist/theme/black.css">
			<link rel="stylesheet" href="dist/theme/night-custom.css">

			<!-- Theme used for syntax highlighted code -->
			<link rel="stylesheet" href="plugin/highlight/monokai.css">
			<link rel="stylesheet" href="./node_modules/highlight.js/styles/atom-one-dark-reasonable.css">
			</head>
			<body>
			<div class="reveal">
			<div class="slides">
			<section>Slide 1</section>
			<section>Slide 2</section>
			<section>
			<h2>Web-Entwicklung</h2>
			</section>
			<section>
			<section>
			<h2>Agenda</h2>
			</section>
			<section>
			<h3>Grundlagen</h3>
			<ul>
			<li>HTML/CSS/JS</li>
			<li>HTTP-Protokoll</li>
			<li>JSON</li>
			</ul>
			</section>
			<section>
			<h3>Fortgeschrittenes</h3>
			<ul>
			<li>JavaScript</li>
			<li>Responsive Design</li>
			<li>NodeJS</li>
			<li>WebComponents / lit</li>
			<li>Datenbank</li>
			</ul>
			</section>
			<section>
			<h3>Architektur & Paradigmen</h3>
			<ul>
			<li>Funktionale Programmierung</li>
			<li>Objektorientierte Programmierung</li>
			<li>Entwurfsmuster (Singleton, Factory, Builder...)</li>
			<li>SOLID-Prinzipien</li>
			<li>Dependency Injection</li>
			<li>MVC</li>
			<li>Redux</li>
			</ul>
			</section>
			<section>
			<h3>Interessante Technologien</h3>
			<ul>
			<li>Canvas-Element</li>
			<li>CSS-Animationen</li>
			<li>WebSockets</li>
			<li>WebWorker</li>
			<li>ServiceWorker</li>
			<li>WebRTC</li>
			<li>WebGL</li>
			<li>Progressive Web Application</li>
			<li>CEF / Electron</li>
			<li>WebAssembly</li>
			</ul>
			</section>
			<section>
			<h3>Betrieb</h3>
			<ul>
			<li>Server einrichten</li>
			<li>SSL- / TLS-Zertifikate</li>
			</ul>
			</section>
			<section>
			<h3>Workflows</h3>
			<ul>
			<li>Git</li>
			<li>Test Driven Development</li>
			<li>Continuous Integration / Continuous Delivery</li>
			</ul>
			</section>
			</section>
			<section>
			<section>
			<h2>HTML</h2>
			</section>
			<section>
			<ul>
			<li>HyperText Markup Language</li>
			<li>Erste Version 1993 von Tim Berners-Lee</li>
			<li>Dokumentationsmedium</li>
			<li>Ursprünglich rein akademische Verwendung</li>
			<li>Verlinkungen der Dokumente macht sie "hyper"</li>
			</ul>
			</section>
			<section>
			<table>
			<tr><th>Version</th><th>Erscheinung</th><th>Elemente ca.</th></tr>
			<tr><td>HTML 1.0</td><td>1993</td><td>20</td></tr>
			<tr><td>HTML 2.0</td><td>1995</td><td>50</td></tr>
			<tr><td>HTML 3.2</td><td>1997</td><td>70</td></tr>
			<tr><td>HTML 4.01</td><td>1999</td><td>90</td></tr>
			<tr><td>HTML 5.0</td><td>2014</td><td>110</td></tr>
			</table>
			</section>
			<section>
			<ul>
			<li>Heute ein "lebender Standard" (Living Standard)</li>
			<li>Stetige inkrementelle Erweiterung</li>
			</ul>
			</section>
			<section>
			<h3>Grundgerüst</h3>
			<pre>
			<code class="html" data-trim data-line-numbers>
			<script type="text/template">
			<!DOCTYPE html>
			<html lang="de">
			<head>
			<meta charset="UTF-8">
			</head>
			<body>
			</body>
			</html>
			</script>
			</code>
			</pre>
			</section>
			<section>
			<h3>Beispiel</h3>
			<pre>
			<code class="html" data-trim data-line-numbers>
			<script type="text/template">
			<!DOCTYPE html>
			<html lang="en">
			<head>
			<meta charset="UTF-8">
			<title>Title</title>
			</head>
			<body>
			<h1>Lorem Ipsum</h1>
			<div>
			<p>Lorem ipsum dolor sit amet, consectetuer adipiscing</p>
			<a href="/assets/html/simple2.html">Weitere Infos</a>
			</div>
			</body>
			</html>
			</script>
			</code>
			</pre>
			</section>
			<section>
			<h3>Beispiel</h3>
			<iframe data-src="/assets/html/simple.html"></iframe>
			</section>
			<section>
			<h3>Aufbau eines Elements</h3>
			<pre>
			<code class="html" data-trim>
			<script type="text/template">
			<span id="my-id" class="super important">Inhalt</span>
			</script>
			</code>
			</pre>
			<pre>
			<code class="html" data-trim>
			<script type="text/template">
			<!-- HTML 4.01 -->
			<input id="input" class="super important" disabled="disabled" />
			</script>
			</code>
			</pre>
			<pre>
			<code class="html" data-trim>
			<script type="text/template">
			<!-- HTML 5 -->
			<input id="input2" class="super important" disabled>
			</script>
			</code>
			</pre>
			</section>
			</section>
			<section>
			<section>
			<h2>CSS</h2>
			</section>
			<section>
			<ul>
			<li>Cascading Style Sheet</li>
			<li>Nach größerer Verbreitung von HTML</li>
			<li>Webseiten ansprechend gestalten</li>
			</ul>
			</section>
			<section>
			<img data-src="/assets/images/css-sucks.png">
			</section>
			<section>
			<h3>Beispiel</h3>
			<pre>
			<code class="css" data-trim data-line-numbers>
			selector [, selector, selector, ...] {
			property: value;
			}
			</code>
			</pre>
			</section>
			<section>
			<h3>Beispiel</h3>
			<pre>
			<code class="css" data-trim data-line-numbers>
			html {
			background-color: red;
			font-size: 30px;
			}
			</code>
			</pre>
			</section>
			<section>
			<h3>Beispiel</h3>
			<pre>
			<code class="html" data-trim data-line-numbers>
			<script type="text/template">
			<html lang="en">
			<head>
			...
			<style>
			html {
			background-color: red;
			font-size: 30px;
			}
			</style>
			</head>
			<body>
			...
			</body>
			</html>
			</script>
			</code>
			</pre>
			</section>
			<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>
			<li>Geschwister, direkte Nachfolger</li>
			<li>Attribute</li>
			<li>Pseudoklassen</li>
			</ul>
			</section>
			<section>
			<h3>Selektoren</h3>
			<pre>
			<code class="css" data-trim data-line-numbers>
			#my-id /* ID */
			html, body /* Mehrfachselektion */
			div > p /* p die direkt unterhalb eines div sind */
			div p /* p die irgendwo unterhalb eines div sind */
			a:visited /* besuchte Links */
			div:hover /* divs über die man mit der Maus fährt */
			span.important /* span mit der Klasse "important" */
			</code>
			</pre>
			</section>
			<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>
			display: block;
			</code>
			</pre>
			</section>
			<section>
			<p>Kann Breite und Höhe haben</p>
			<pre>
			<code class="css" data-trim data-line-numbers>
			display: block;
			width: 20px;
			height: 20px;
			</code>
			</pre>
			</section>
			<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>
			display: inline;
			</code>
			</pre>
			</section>
			<section>
			<p>Festlegen von Breite und Höhe sind wirkungslos</p>
			<pre>
			<code class="css" data-trim data-line-numbers>
			display: inline;
			width: 20px; /* kein Effekt */
			height: 20px; /* kein Effekt */
			</code>
			</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(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.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>
			<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>
			</div>
			</div>

			@@ -31,6 +1809,8 @@
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