<paper-autocomplete>

Use paper-autocomplete to add autocomplete functionality to the input elements. It also works wilt polymer inputs.

The element works with static list of suggestions or with dynamic (asynchronous) operation that require calling te backend or local datastore. In second case you should set loader property which will display a loader animation while results are loaded.

You must associate suggestions with the input field. This can be done by passing an element reference to the target property.

Example:

Static suggestions

<paper-input label="Enter fruit name" id="fruits"></paper-input>
<paper-autocomplete id="fruitsSuggestions"></paper-autocomplete>

const ac = document.getElementById('fruitsSuggestions');
ac.target = document.getElementById('fruits');
ac.source = ['Apple', 'Orange', 'Bananas'];

or defined in an attribute:

<paper-autocomplete source='["Apple", "Orange", "Bananas"]'></paper-autocomplete>

Dynamic suggestions

<paper-input-container>
  <label>Enter friut name</label>
  <iron-input slot="input">
    <input id="asyncField">
  </iron-input>
</paper-input-container>
<paper-autocomplete loader id="fruitAsync"></paper-autocomplete>

const ac = document.querySelector('#fruitAsync');
ac.target = document.querySelector('#asyncField');
ac.addEventListener('query', (e) => {
  const query = e.detail.value;
  // some function go get results.
  asyncQuery(query, (suggestions) => {
    e.target.source = suggestions;
  });
});

New in 3.1.0

• Replaced Polymer with LitElement
• Upgraded testing framework and tests
• All changes are backward compatible
• Breaking: removing value property. It wasn't ever set and used
• New: Adding selected property that represent selected item from source array
• New: Adding noink proeprty to disable ripple effect when clicking on a list item
• New: Added support for ARIA and role attributes
• New: Added onquery and onselected setters and getters
• Deprecated open-on-focus attribute, use openonfocus instead
• Deprecated selected-item attribute, use selecteditem instead

Rendering the suggestions

Suggestions array can be either an array of strings or objects. For strings, displayed in the list and inserted to the input field value is the same item.

You can set different list item display value and value inserted into the field when the array contains object. Each object must contain value and display properties where value property will be inserted into the text field and display will be used to display description inside the list.

// Simple suggestions
autocomplete.source = ['Apple', 'Orange', 'Bananas'];

// Complex suggestions
autocomplete.source = [
  { id: 1, value: 'Apple' },
  { id: 2, value: 'Bananas' },
  { id: 3, value: 'Orange' }
];

Note, the selected event always contains the string value of the selection. You can read selected item as the original type from selected property of the autocomplete

autocomplete.onselected = (e) {
  const label = e.detail.value;
  // contains suggestion value
  const item = e.target.selected;
  // contains an item from `source`, e.g. `{ id: 1, value: 'Apple' }`
};

Query event

The query event is fired when the user query change in the way so the element is not able to render suggestions properly. This means if the user add a letter to previously entered value the query event will not fire since it already have list of suggestion that should be used to filter suggestions from. And again when the user will delete a letter the element will still have list of source suggestions to filter suggestions from. However, if the user change the query entirely it will fire query event and the app will expect to source to change. Setting source is not mandatory.

Preventing from changing the input value

To prevent the element to update the value of the target input, listent for selected event and cancel it by calling event.preventDefault() function.

Setting target property

To set an input target simply use target property. It accept any element.

In templating system or in an HTML page you may want to use an is of another element to be used as a target. You can set the target as other element's id but only if the referenced element is a descendant of autocomplete's parent element.

<div class="parent">
  <div class="search-bar">
    <label for="search">Search</label>
    <input type="search" id="search"/>
    <button>Search</button>
  </div>
  <paper-autocomplete target="search"></paper-autocomplete>
</div>

In all other cases pass a reference to a HTMLElement element to the target property.

a11y

The element alters the following properties on the target element:

• aria-autocomplete="list"
• autocomplete="off"
• aria-haspopup="true"
• aria-controls is set to autocomplete's id value. If id is not set then it's auto generated.

API components

This components is a part of API components ecosystem

Usage

Installation

npm install --save @advanced-rest-client/paper-autocomplete

In an html file

<html>
  <head>
    <script type="module">
      import '@advanced-rest-client/paper-autocomplete/paper-autocomplete.js';
    </script>
  </head>
  <body>
    <paper-autocomplete></paper-autocomplete>
  </body>
</html>

In a Polymer 3 element

import {PolymerElement, html} from '@polymer/polymer/polymer-element.js';
import '@advanced-rest-client/paper-autocomplete/paper-autocomplete.js';

class SampleElement extends PolymerElement {
  static get template() {
    return html`
    <paper-autocomplete></paper-autocomplete>
    `;
  }
}
customElements.define('sample-element', SampleElement);

Installation

git clone https://github.com/advanced-rest-client/paper-autocomplete
cd paper-autocomplete
npm install

Running the demo locally

npm start

Running the tests

npm test