I\'m trying to work frameworkless, with pure javascript Web Components. I want my Web Components to be able to work stand-alone and be used on different sites, and yet I als
With Web Components you can pass objects through attributes as you said, but you can also pass an object with a method, or throug a property (which is actually a setter method).
<my-component id="comp1"></my-component>
...
var myObject = { y:1, y:2 }
comp1.value = myObject //via property
comp1.setValue( myObject ) //via method
Here is a sample app with two native V1 Web Components. <component-1>
can talk to <component-2>
because you supply an ID into <component-1>
and that ID refers to the ID set on <component-2>
.
This is similar to how the <label>
tag work with its for
attribute.
<component-1 link-id="c2"></component-1>
<hr/>
<component-2 id="c2"></component-2>
// Class for `<component-1>`
class Component1 extends HTMLElement {
constructor() {
super();
this._linkedComponent = null;
this._input = document.createElement('input');
this._input.addEventListener('focus', this._focusHandler.bind(this));
this._button = document.createElement('button');
this._button.textContent = 'Add';
this._button.addEventListener('click', this._clickHandler.bind(this));
}
connectedCallback() {
this.appendChild(this._input);
this.appendChild(this._button);
}
static get observedAttributes() {
return ['link-id'];
}
attributeChangedCallback(attrName, oldVal, newVal) {
if (oldVal !== newVal) {
if (newVal === null) {
this._linkedComponent = null;
}
else {
this._linkedComponent = document.getElementById(newVal);
}
}
}
_clickHandler() {
if (this._linkedComponent) {
this._linkedComponent.value = this._input.value;
}
}
_focusHandler() {
this._input.value = '';
}
}
// Class for `<component-2>`
class Component2 extends HTMLElement {
constructor() {
super();
this._textArea = document.createElement('textarea');
this._textArea.setAttribute('style','width:100%;height:200px;');
}
connectedCallback() {
this.appendChild(this._textArea);
}
set value(newValue) {
this._textArea.value += (newValue+'\n');
}
}
customElements.define('component-1', Component1);
customElements.define('component-2', Component2);
<component-1>
will only talk to <component-2>
if there is a component with the ID that was provided to <component-1>
through its link-id
attribute.