add web components styling (part, exportparts, ::slotted)

Sascha Schulz

2024-02-19 ae66b713f087d2298fe4db7ae67e68453a30dfc0

 index.html

@@ -2903,6 +2903,14 @@
                  </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>
@@ -2991,6 +2999,7 @@
                        &lt;/html>
                     </code>
                  </pre>
                  <p>Ein Muss für alle responsiven Seiten</p>
               </section>
               <section>
                  <pre>
@@ -3001,6 +3010,885 @@
                     </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="">
                        &lt;div class="grid"&gt;
                           &lt;span&gt;A&lt;/span&gt;
                           &lt;span&gt;B&lt;/span&gt;
                           &lt;span&gt;C&lt;/span&gt;
                           &lt;span&gt;D&lt;/span&gt;
                           &lt;span&gt;E&lt;/span&gt;
                           &lt;span&gt;F&lt;/span&gt;
                        &lt;/div&gt;
                     </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="">
                        &lt;div class="grid"&gt;
                           &lt;span class="a"&gt;A&lt;/span&gt;
                           &lt;span class="b"&gt;B&lt;/span&gt;
                        &lt;/div&gt;
                     </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="">
                        &lt;div class="grid"&gt;
                           &lt;div class="area navigation"&gt;Navigation&lt;/div&gt;
                           &lt;div class="area header"&gt;Header&lt;/div&gt;
                           &lt;div class="area content"&gt;Content&lt;/div&gt;
                           &lt;div class="area footer"&gt;Footer&lt;/div&gt;
                        &lt;/div&gt;
                     </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>&lt;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>&lt;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>&lt;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>
         </div>
      </div>