add nodejs intro

Sascha Schulz

2024-06-10 28563b57efe49cc9869ed3bc5d3fd3a6a73afcce

 index.html

@@ -3965,7 +3965,162 @@
            </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>
         </div>