polymerelements / iron-checked-element-behavior

Implements an element that has a checked attribute and can be added to a form

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

iron-checked-element-behavior's Issues

Custom validator is not considered

Shouldn’t the _getValidity method look like this to consider custom validators?

    _getValidity: function(value) {
      if (this.hasValidator()) {
        return this._validator.validate(value);
      }
      return this.disabled || !this.required || this.checked;
    }

https://github.com/PolymerElements/iron-checked-element-behavior/blob/master/iron-checked-element-behavior.html#L80-L82

Wrong Reference in bower file for 2.0 preview

Description

The reference for iron-form-element-behavior is pointing at 1.0.0

PolymerElements/iron-form-element-behavior#^1.0.0

Expected outcome

This should be pointing to the 2.0 preview branch

There is no documentation for Polymer.IronCheckedElementBehavior

At least according to the popup when I try to click the documentation in paper-checkbox --
https://elements.polymer-project.org/elements/paper-checkbox

Why IronCheckedElementBehavior is not in PolymerElements/iron-behaviors?

Merge into Polymer/iron-behaviors

Shouldn't this technically be a part of the iron-behaviors repository? It is an iron behavior and many elements have to use both this and iron-behaviors. In my opinion it's more semantically correct to merge the two.

boolean factorization

return this.disabled || !this.required || (this.required && this.checked);
  is equivalent to
return this.disabled || !this.required || this.checked;

https://github.com/PolymerElements/iron-checked-element-behavior/blob/master/iron-checked-element-behavior.html#L81

iron-checked-element-behavior included in iron-elements

Just asking, iron-checked-element-behavior gonna be included either in the iron-elements package or in iron-behaviors right?
I saw it's been only one week since last update (as well as in the paper-toggle-button). So no hurry to include them but just to write down if I have to remove single dependancy afterwards or not, thanks!