JarCasting
IronCheckedElementBehavior
Use IronCheckedElementBehavior to implement a custom element that has a checked property, which can be used for validation if the element is also required. Element instances implementing this behavior will also be registered for use in an iron-form element.
See: Documentation, Demo.
Usage
Installation
npm install --save @polymer/iron-checked-element-behavior
In a Polymer 3 element
import {PolymerElement} from '@polymer/polymer/polymer-element.js';
import {mixinBehaviors} from '@polymer/polymer/lib/legacy/class.js';
import {html} from '@polymer/polymer/lib/utils/html-tag.js';
import {IronCheckedElementBehavior} from '../iron-checked-element-behavior.js';
class SimpleCheckbox extends mixinBehaviors(IronCheckedElementBehavior, PolymerElement) {
static get template() {
return html`
<style>
:host([invalid]) {
color: red;
}
</style>
<button on-click="_checkValidity">validate</button>
<input type="checkbox" id="checkbox" checked="{{checked::input}}">
<span id="labelText">{{label}}</span>
`;
}
static get properties() {
return {label: {type: String, value: 'not validated'}};
}
_checkValidity() {
this.validate();
this.label = this.invalid ? 'is invalid' : 'is valid';
}
}
customElements.define('simple-checkbox', SimpleCheckbox);
Contributing
If you want to send a PR to this element, here are the instructions for running the tests and demo locally:
Installation
git clone https://github.com/PolymerElements/iron-checked-element-behavior
cd iron-checked-element-behavior
npm install
npm install -g polymer-cli
Running the demo locally
polymer serve --npm
open http://127.0.0.1:<port>/demo/
Running the tests
polymer test --npm
