@advanced-rest-client/paper-autocomplete

<paper-autocomplete> element

<input id="userInput"/>
<paper-autocomplete id="ac" source='["Apple", "Orange", "Bananas"]'></paper-autocomplete>
<script>
document.getElementById('ac').target = document.getElementById('userInput');
</script>

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" on-query="_asyncSuggestions"></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;
  });
});

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 onject. 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.

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.