<!DOCTYPE html><html><head><metacharset="utf-8"><metaname="viewport"content="width=device-width, initial-scale=1"><metaname="description"content="Introducing a library."><title>`deka-dom-el` — Introduction</title><!--<dde:mark type="component" name="metaAuthor" host="this" ssr/>--><metaname="author"content="Jan Andrle"><linktype="text/plain"rel="author"href="https://jaandrle.github.io/humans.txt"><metaname="generator"content="deka-dom-el"><!--<dde:mark type="component" name="metaTwitter" host="this" ssr/>--><metaname="twitter:card"content="summary_large_image"><metaname="twitter:url"content="https://github.com/jaandrle/deka-dom-el"><metaname="twitter:title"content="deka-dom-el"><metaname="twitter:description"content="A low-code library that simplifies the creation of native DOM elements/components using small wrappers and tweaks."><metaname="twitter:creator"content="@jaandrle"><!--<dde:mark type="component" name="metaFacebook" host="this" ssr/>--><metaname="og:url"content="https://github.com/jaandrle/deka-dom-el"><metaname="og:title"content="deka-dom-el"><metaname="og:description"content="A low-code library that simplifies the creation of native DOM elements/components using small wrappers and tweaks."><metaname="og:creator"content="@jaandrle"><scriptsrc="https://cdn.jsdelivr.net/npm/shiki@0.9"defer=""></script><scripttype="module"src="code.js.js"></script><scriptsrc="https://flems.io/flems.html"type="text/javascript"charset="utf-8"></script><linkrel="stylesheet"href="global.css"></head><body><!--<dde:mark type="component" name="page" host="this" ssr/>--><!--<dde:mark type="component" name="simplePage" host="this" ssr/>--><!--<dde:mark type="component" name="header" host="this" ssr/>--><header><h1>`deka-dom-el` — Introduction</h1><p>Introducing a library.</p></header><nav><ahref="https://github.com/jaandrle/deka-dom-el"><svgclass="icon"viewBox="0 0 32 32"><!--<dde:mark type="component" name="iconGitHub" host="parentElement" ssr/>--><pathd="M 16,0.395c -8.836,0 -16,7.163 -16,16c 0,7.069 4.585,13.067 10.942,15.182c 0.8,0.148 1.094,-0.347 1.094,-0.77c 0,-0.381 -0.015,-1.642 -0.022,-2.979c -4.452,0.968 -5.391,-1.888 -5.391,-1.888c -0.728,-1.849 -1.776,-2.341 -1.776,-2.341c -1.452,-0.993 0.11,-0.973 0.11,-0.973c 1.606,0.113 2.452,1.649 2.452,1.649c 1.427,2.446 3.743,1.739 4.656,1.33c 0.143,-1.034 0.558,-1.74 1.016,-2.14c -3.554,-0.404 -7.29,-1.777 -7.29,-7.907c 0,-1.747 0.625,-3.174 1.649,-4.295c -0.166,-0.403 -0.714,-2.03 0.155,-4.234c 0,0 1.344,-0.43 4.401,1.64c 1.276,-0.355 2.645,-0.532 4.005,-0.539c 1.359,0.006 2.729,0.184 4.008,0.539c 3.054,-2.07 4.395,-1.64 4.395,-1.64c 0.871,2.204 0.323,3.831 0.157,4.234c 1.026,1.12 1.647,2.548 1.647,4.295c 0,6.145 -3.743,7.498 -7.306,7.895c 0.574,0.497 1.085,1.47 1.085,2.963c 0,2.141 -0.019,3.864 -0.019,4.391c 0,0.426 0.288,0.925 1.099,0.768c 6.354,-2.118 10.933,-8.113 10.933,-15.18c 0,-8.837 -7.164,-16 -16,-16Z"></path></svg>GitHub</a><ahref="./"title="Introducing a library."class="current">1. Introduction</a><ahref="p02-elements"title="Basic concepts of elements modifications and creations.">2. Elements</a><ahref="p03-events"title="Using not only events in UI declaratively.">3. Events and Addons</a><ahref="p04-signals"title="Handling reactivity in UI via signals.">4. Signals and reactivity</a><ahref="p05-scopes"title="Organizing UI into components">5. Scopes and components</a><ahref="p06-customElement"title="Using custom elements in combinantion with DDE">6. Web Components</a></nav><main><p>The library tries to provide pure JavaScript tool(s) to create reactive interfaces using …</p><h3id="h-event-driven-programming--parts-separation--ps"><!--<dde:mark type="component" name="h3" host="parentElement" ssr/>--><ahref="#h-event-driven-programming--parts-separation--ps"tabindex="-1">#</a> Event-driven programming (3 parts separation ≡ 3PS)</h3><p>Let's introduce the basic principle on which the library is built. We'll use the JavaScript listener as a starting point. </p><divclass="code"data-js="todo
const onchage=
event=>
console.log("Reacting to the:", event); // A
input.addEventListener("change", onchange); // B
input.dispatchEvent(new Event("change")); // C
</code></div><p>As we can see, in the code at location “A” we define <em>how to react</em> when the function is called with any event as an argument. At that moment, we <em>don't care who/why/how</em> the function was called. Similarly, at point “B”, we reference to a function to be called on the event <em>without caring</em> what the function will do at that time. Finally, at point “C”, we tell the application that a change has occurred, in the input, and we <em>don't care if/how someone</em> is listening for the event.</p><!--<dde:mark type="component" name="example" host="this" ssr/>--><divid="code-example-1-8meex5b3tyo"class="example"><!--<dde:mark type="component" name="code" host="parentElement" ssr/>--><codeclass="language-js">import { el } from "./esm-with-signals.js";