@polymer/iron-selector

<iron-selector>, IronSelectableBehavior, IronMultiSelectableBehavior

iron-selector is an element which can be used to manage a list of elements that can be selected. Tapping on the item will make the item selected. The selected indicates which item is being selected. The default is to use the index of the item. iron-selector's functionality is entirely defined by IronMultiSelectableBehavior.

IronSelectableBehavior gives an element the concept of a selected child element. By default, the element will select one of its selectable children when a 'tap' event (synthesized by Polymer, roughly 'click') is dispatched to it.

IronSelectableBehavior lets you ...

• decide which children should be considered selectable (selectable),
• retrieve the currently selected element (selectedItem) and all elements in the selectable set (items),
• change the selection (select, selectNext, etc.),
• decide how selected elements are modified to indicate their selected state (selectedClass, selectedAttribute),

... among other things.

IronMultiSelectableBehavior includes all the features of IronSelectableBehavior as well as a multi property, which can be set to true to indicate that the element can have multiple selected child elements. It also includes the selectedItems and selectedValues properties for working with arrays of selectable elements and their corresponding values (multi is true) - similar to the single-item versions provided by IronSelectableBehavior: selectedItem and selected.

See: Documentation, Demo.

Usage

Installation

npm install --save @polymer/iron-selector

In an HTML file

  
    
  
  
    
      <div>Item 1</div>
      <div>Item 2</div>
      <div>Item 3</div>
    
  

In a Polymer 3 element

import {PolymerElement} from '@polymer/polymer/polymer-element.js';
import {html} from '@polymer/polymer/lib/utils/html-tag.js';

import '@polymer/iron-selector/iron-selector.js';

class ExampleElement extends PolymerElement {
  static get template() {
    return html`
      
        <div>Item 1</div>
        <div>Item 2</div>
        <div>Item 3</div>
      
    `;
  }
}

customElements.define('example-element', ExampleElement);

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-selector
cd iron-selector
npm install
npm install -g polymer-cli

Running the demo locally

polymer serve --npm
open https://127.0.0.1:/demo/

Running the tests

polymer test --npm