From 8661e4358cd8a40e94c39f40b6147a5f37a7c7d3 Mon Sep 17 00:00:00 2001
From: Sascha Schulz <sschulz@dh-software.de>
Date: Fr, 26 Jul 2024 09:54:43 +0200
Subject: [PATCH] Merge branch 'draft'
---
assets/images/node-js.svg | 3
index.html | 339 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
assets/drawio/node-js.drawio | 1
3 files changed, 334 insertions(+), 9 deletions(-)
diff --git a/assets/drawio/node-js.drawio b/assets/drawio/node-js.drawio
new file mode 100644
index 0000000..98e176a
--- /dev/null
+++ b/assets/drawio/node-js.drawio
@@ -0,0 +1 @@
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\ No newline at end of file
diff --git a/assets/images/node-js.svg b/assets/images/node-js.svg
new file mode 100644
index 0000000..9e6b508
--- /dev/null
+++ b/assets/images/node-js.svg
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="802px" height="502px" viewBox="-0.5 -0.5 802 502"><defs/><g><rect x="10" y="10" width="360" height="480" fill="rgb(42, 42, 42)" stroke="rgb(240, 240, 240)" stroke-width="2" pointer-events="all"/><rect x="130" y="10" width="120" height="60" fill="none" stroke="none" pointer-events="all"/><g transform="translate(-0.5 -0.5)scale(2)"><switch><foreignObject pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility" style="overflow: visible; text-align: left;"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 58px; height: 1px; padding-top: 20px; margin-left: 66px;"><div data-drawio-colors="color: rgb(240, 240, 240); " style="box-sizing: border-box; font-size: 0px; text-align: center;"><div style="display: inline-block; font-size: 12px; font-family: Helvetica; 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diff --git a/index.html b/index.html
index 4e7cb28..91a7015 100644
--- a/index.html
+++ b/index.html
@@ -36,9 +36,16 @@
<ul>
<li>JavaScript</li>
<li>Responsive Design</li>
- <li>NodeJS</li>
<li>WebComponents / lit</li>
+ <li>NodeJS</li>
<li>Datenbank</li>
+ </ul>
+ </section>
+ <section>
+ <h3>Betrieb</h3>
+ <ul>
+ <li>Server einrichten</li>
+ <li>SSL- / TLS-Zertifikate</li>
</ul>
</section>
<section>
@@ -66,13 +73,6 @@
<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>
@@ -3916,7 +3916,328 @@
</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>
+ <p>Entwickle eine Tab-Komponente (Vorlage "tab-componenmt.html"), welche beim Click auf einen Registerreite / Tab ein Event feuert, welches die Außenwelt über das gerade aktivierte Tab (tab-id) informiert</p>
+ </section>
+ <section>
+ <h3>Lösung</h3>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ this.root.innerHTML = `
+ <style>
+ ::slotted(div) {
+ display: none;
+ }
+
+ ::slotted(div.active) {
+ display: block;
+ }
+ </style>
+
+ <div><slot name="tab"></slot></div>
+ <div><slot name="content"></slot></div>
+ `;
+ </code>
+ </pre>
+ </section>
+ <section>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ connectedCallback() {
+ const firstContent = this.querySelector("div");
+
+ firstContent.classList.add("active");
+
+ this.addEventListener("click", (e) => {
+ if (e.target.tagName === "SPAN" && e.target.hasAttribute("tab-id")) {
+ const oldContent = this.querySelector("div.active");
+ const newContent = this.querySelector(`[tab-id="${e.target.getAttribute("tab-id")}"]`);
+
+ oldContent.classList.remove("active");
+ newContent.classList.add("active");
+
+ this.dispatchEvent(new CustomEvent("tabclick", {composed: true, bubbles: true, detail: e.target.getAttribute("tab-id"), cancelable: true}));
+ }
+ });
+ }
+ </code>
+ </pre>
+ </section>
+ </section>
+ <section>
+ <section>
+ <h2>NodeJS</h2>
+ </section>
+ <section>
+ <h3>Was ist NodeJS?</h3>
+ <ul>
+ <li class="fragment">"JavaScript auf dem Server"</li>
+ <li class="fragment">basiert auf der V8-Engine von Google</li>
+ <li class="fragment">Laufzeitumgebung für JavaScript mit eigener API</li>
+ </ul>
+ </section>
+ <section>
+ <img data-src="/assets/images/node-js.svg">
+ </section>
+ <section>
+ <h3>Überblick über die Node-API</h3>
+ <p>Die API ist in viele verschiedene Module aufgeteilt</p>
+ <table>
+ <tr><td>fs</td><td>Dateisystem</td></tr>
+ <tr><td>crypto</td><td>Kryptografie</td></tr>
+ <tr><td>zlib</td><td>Datenkompression</td></tr>
+ <tr><td>http</td><td>Webserver</td></tr>
+ <tr><td>net</td><td>Netzwerk (TCP)</td></tr>
+ <tr><td>tls</td><td>Verschlüsseltes Netzwerk (TCP)</td></tr>
+ </table>
+ </section>
+ <section>
+ <p>Aufruf eines Programmes in der Kommandozeile</p>
+ <pre>
+ <code class="bash" data-trim data-line-numbers>
+ node [Node-Parameter] path/to/script.js [Anwendungsparameter]
+ </code>
+ </pre>
+ <p>z.B.</p>
+ <pre>
+ <code class="bash" data-trim data-line-numbers>
+ node --inspect index.js --port 3000
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Einbinden von Modulen</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ const fs = require("fs");
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Aufbau eines Moduls</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ module.exports = {
+ foo: 5,
+ sayHello: function(name) {
+ return "Hello " + name + "!";
+ }
+ }
+ </code>
+ </pre>
+ <p>oder</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ exports.foo = 5;
+ exports.sayHello = function(name) {
+ return "Hello " + name + "!";
+ };
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Aufgabe</p>
+ <p>Schreibe ein Modul, welches eine <code>Square</code>-Klasse zur Verfügung stellt, mit welchem man den Umfang und den Flächeninhalt eines Rechtecks berechnen kann:</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ const Square = require("./square");
+
+ const square = new Square(2, 3);
+
+ console.log(square.getArea()); // => 6
+ console.log(square.getPerimeter()); // => 10
+ </code>
+ </pre>
+ </section>
+ <section>
+ <h3>Module für die Kommandozeile</h3>
+ <p>package.json</p>
+ <pre>
+ <code class="bash" data-trim data-line-numbers>
+ npm init -y
+ </code>
+ </pre>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ {
+ ...
+ "bin": {
+ "my-command": "./index.js"
+ }
+ }
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>index.js</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ #! /usr/bin/env node
+
+ console.log("Hello world from the command line!");
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Installation</p>
+ <pre>
+ <code class="bash" data-trim data-line-numbers>
+ npm install -g path/to/project
+ </code>
+ </pre>
+ z.B.
+ <pre>
+ <code class="bash" data-trim data-line-numbers>
+ npm install -g .
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Ausführung</p>
+ <pre>
+ <code class="bash" data-trim data-line-numbers>
+ my-command
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Kommandozeilenparameter</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ console.log(process.argv);
+ </code>
+ </pre>
+ <p>angelehnt an die Parameter aus der Programmiersprache <code>c</code>:</p>
+ <pre>
+ <code class="c" data-trim data-line-numbers>
+ int main(int argc, char *argv[])
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Aufgabe</p>
+ <p>Mache das vorherige Programm für die Konsole aufrufbar, sodass die Länge und Breite für das Rechteck per Konsolenargumente übergeben werden können und der Flächeninhalt ausgegeben wird:</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ my-command 2 3
+ </code>
+ </pre>
+ </section>
+ <section>
+ <h3>Buffer</h3>
+ <p>Array-artige Struktur für rohe Bytes</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ const b1 = Buffer.from("abc"); // bevorzugt
+ const b2 = Buffer.alloc(100, 0); // Länge mit initialen Daten
+ const b3 = Buffer.allocUnsafe(100); // Länge ohne initiale Daten
+ const b4 = new Buffer("abc"); // offiziell nicht empfohlen
+
+ console.log(b1); // => <Buffer 61 62 63>
+ console.log(b1.toString("hex")); // => "616263"
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Mit Buffern arbeiten:</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ const a = Buffer.from("a") + Buffer.from("b");
+ const b = Buffer.concat([Buffer.from("a"), Buffer.from([98])]);
+ const c = b.toString()
+
+ console.log(a); // => ab
+ console.log(b); // => <Buffer 61 62>
+ console.log(c); // => ab
+
+ for (const byte of a) {
+ console.log(byte); // => 97 98
+ }
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Aufgabe</p>
+ <p>Implementiere eine XOR-Verschlüsselung (<code>^</code>-Operator), sodass jedes Byte einer Original-Nachricht der Reihe nach mit dem entsprechenden Byte eines Schlüsselwortes verschlüsselt wird und gebe die verschlüsselte Nachricht als Text aus.</p>
+ </section>
+ <section>
+ <p>Aufgabe</p>
+ <p>Implementiere zur vorherigen Verschlüsselung eine Entschlüsselung.</p>
+ </section>
+ <section>
+ <p>Lösung</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ const word = Buffer.from("abcdef");
+ const key = Buffer.from("xyz");
+ const encrypted = Buffer.alloc(word.length, 0);
+
+ // encrypt
+ for (let i = 0; i < word.length; i++) {
+ encrypted[i] = word[i] ^ key[i % key.length];
+ }
+
+ // decrypt
+ for (let i = 0; i < word.length; i++) {
+ word[i] = encrypted[i] ^ key[i % key.length];
+ }
+
+ console.log(word.toString()); // => "abcdef"
+ </code>
+ </pre>
+ </section>
+ <section>
+ <h3>Streams</h3>
+ <p>Konstanter Fluss von (meist) großen Datenmengen in kleinen Paketen</p>
+ </section>
+ <section>
+ <p>Gängige Typen von Streams</p>
+ <ul>
+ <li>Standard In / Out</li>
+ <li>HTTP-Requests / -Responses</li>
+ <li>TCP-Sockets</li>
+ <li>Lese- und Schreib-Streams auf Dateien</li>
+ <li>Große Datenbank-Ergebnisse mittels Cursor</li>
+ </ul>
+ </section>
+ <section>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ const readableStream = fs.createReadStream("./source.txt");
+ const writableStream = fs.createWriteStream("./target.txt");
+
+ readableStream.on("data", (data /* Buffer */) => {
+ // process data here
+ writableStream.write(data)
+ });
+
+ readableStream.on("end", (data) => {
+ // stream has finished, e.g. EOF (end of file)
+ });
+
+ // alternatively pipe content
+ readableStream.pipe(writableStream);
+ </code>
+ </pre>
+ </section>
+ <section>
+ <p>Aufgabe</p>
+ <p>Lese eine beliebige Datei als Readable Stream, verschlüssele den Inhalt mit der XOR-Methode und schreibe die verschlüsselten Bytes in eine Zieldatei</p>
+ </section>
+ <section>
+ <p>Aufgabe</p>
+ <p>Ändere das Programm, sodass auf Konsolenebene ein Pipe (|) ermöglicht wird:</p>
+ <pre>
+ <code class="bash" data-trim data-line-numbers>
+ echo "Hello World!" | node index.js
+ </code>
+ </pre>
+ <p>Nutze dafür die implizit vorhandenen Streams von Standard In / Out:</p>
+ <pre>
+ <code class="js" data-trim data-line-numbers>
+ process.stdin; // Readable Stream
+ process.stdout; // Writable Stream
+ </code>
+ </pre>
</section>
</section>
</div>
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