wecu
v3.2.1
Published
A library for building composable, reactive web components.
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55
Maintainers
calebowenspersonReadme
Web Element Composition Utility
Due to limitations in typescripts .d.ts type declarations, its not possible to mark properties as private or protected. To try and help you understand what is intended for the user to call, I have prefixed "unsafe" methods with an underscore.
API Documentation
To view API docs visit https://calebowens.github.io/web-element-composition-utility/
About
WECU is a library that lets you create web components and compose them together using an intuitive OO system.
The idea behind WECU is that it lets the user take control of the program, with the user calling it on their own terms. WECU is based arround the idea that the GUI is bound to your data in the class, just how your actions are also. It results in creating a nice abstraction over the DOM for implementing reactive behaviour without taking any control away from the programmer like a framework would.
Who This is For
This library will be ideal for:
- People who want to be able to manage each part of their web app
- Still want convenience of being able to create and compose components
- Would like to be able to program in a more traditional OOP way
Demo Projects
I've written a demo project using webpack and typescript that I encourage you to check out at https://github.com/calebowens/wecu-example
Using Deno as Bundler
For usage with deno you can use the import link https://deno.land/x/wecu@<VERSION_NUMBER>/deno_dist/index.ts.
For bundling deno you'll need to use the enable libs "dom" and "es2015" in your deno.json.
Examples
These examples have been written with the following typescript setup in mind:
- Run
yarn add typescript vite - Add
tsconfig.json
{
"compilerOptions": {
"target": "es2015",
"experimentalDecorators": true,
"moduleResolution": "node",
"outDir": "./lib",
"esModuleInterop": true,
"declaration": true,
"strict": true
},
"include": [
"./src"
]
}- Run
yarn vite
Root of an app
main.ts
import { Component, P, mountComponent } from "wecu";
class Root extends Component {
render() {
return [new P("Hello World!")];
}
}
mountComponent(Root, '#app')index.html
<!DOCTYPE html>
<html>
<head>
<script src="main.js" async defer></script>
</head>
<body>
<div id="app"></div>
</body>
</html>Conditional Rendering
main.ts
import { Component, P, Button, mountComponent } from "wecu";
class Root extends Component {
private toggle = new Button("Toggle");
private show = true;
constructor() {
super();
this.toggle.element.addEventListener("click", () => {
this.show = !this.show; // We've modified state so we need to re-render the button
this.rerender();
});
}
render() {
if (this.show) {
return [new P("HelloThere!"), this.toggle];
} else {
return [this.toggle];
}
}
}
mountComponent(Root, '#app')index.html
<!DOCTYPE html>
<html>
<head>
<script src="main.js" async defer></script>
</head>
<body>
<div id="app"></div>
</body>
</html>Using an observable variable
main.ts
import { Component, Observable, P, Button, mountComponent } from "wecu";
class Root extends Component {
private toggle = new Button("Toggle");
private show = new Observable(true);
constructor() {
super();
// Register the event listener on the internal element of the button
this.toggle.element.addEventListener("click", () => {
this.show.value = !this.show.value;
});
// Rather than calling rerender in the button event listener, I can
// observe the value for changes
this.show.onUpdate(() => {
this.rerender();
});
}
render() {
if (this.show) {
return [new P("Hello There!"), this.toggle];
} else {
return [this.toggle];
}
}
}
mountComponent(Root, '#app')index.html
<!DOCTYPE html>
<html>
<head>
<script src="main.js" async defer></script>
</head>
<body>
<div id="app"></div>
</body>
</html>Registering a Component as a Web Component
main.ts
import { Component, registerComponent, P } from "wecu";
class Root extends Component {
render() {
return [new P("Hello World!")];
}
}
registerComponent(Root, "x-root");index.html
<!DOCTYPE html>
<html>
<head>
<script src="main.js" async defer></script>
</head>
<body>
<x-root></x-root>
</body>
</html>Styling Components
main.ts
import { Component, registerComponent, P, Style } from "wecu";
class Root extends Component {
render() {
return [
new Style(`
:host {
width: 100%;
}
p {
color: green;
}
`),
new P("Hello World!")
];
}
}
registerComponent(Root, "x-root");index.html
<!DOCTYPE html>
<html>
<head>
<script src="main.js" async defer></script>
</head>
<body>
<x-root></x-root>
</body>
</html>Using an Emitter
main.ts
import { Button, Component, Input, Emitter, P, registerComponent } from "wecu";
export default class CreateTask extends Component {
private addTask = new Button("Create Task");
private input = new Input();
public taskEmitter = new Emitter<string>();
constructor() {
super();
this.addTask.element.addEventListener("click", () => {
this.taskEmitter.emit(this.input.element.value);
this.input.element.value = "";
});
}
render() {
return [this.input, this.addTask];
}
}
export default class Root extends Component {
private tasks: P[] = [];
private taskCreator = new CreateTask();
constructor() {
super();
this.taskCreator.taskEmitter.onEmit((title) => {
this.tasks.push(new P(title));
this.rerender();
});
}
render() {
return [this.taskCreator, ...this.tasks];
}
}
registerComponent(Root, "x-root");index.html
<!DOCTYPE html>
<html>
<head>
<script src="main.js" async defer></script>
</head>
<body>
<x-root></x-root>
</body>
</html>