This example demonstrates how to provide autocomplete suggestions using a DataSource instance. While AutoComplete supports a variety of result sources without requiring a DataSource, using a DataSource can give you more control over how results are retrieved and processed, and also allows you to share data with other DataSource-based widgets on the page.
Type the name of a band or musician to see results from Yahoo! Music. Can't think of one? Try some of my favorites: Dandy Warhols, Black Rebel Motorcycle Club, The Morning After Girls, Dr. Theopolis, or Echo & the Bunnymen.
HTML
Note: be sure to add the yui3-skin-sam classname to the
page's <body> element or to a parent element of the widget in order to apply
the default CSS skin. See Understanding Skinning.
<div id="demo" class="yui3-skin-sam"> <!-- You need this skin class --> <label for="ac-input">Music artist:</label><br> <input id="ac-input" type="text"> </div>
JavaScript
YUI().use('autocomplete', 'autocomplete-highlighters', 'datasource-get', function (Y) {
  // Create a DataSource instance.
  var ds = new Y.DataSource.Get({
    source: 'http://query.yahooapis.com/v1/public/yql?format=json'
  });
  Y.one('#ac-input').plug(Y.Plugin.AutoComplete, {
    maxResults: 10,
    resultHighlighter: 'wordMatch',
    resultTextLocator: 'name',
    // Use the DataSource instance as the result source.
    source: ds,
    // YQL query to use for each request (URL-encoded, except for the
    // {query} placeholder). This will be appended to the URL that was supplied
    // to the DataSource's "source" config above.
    requestTemplate: '&q=select%20*%20from%20music.artist.search%20where%20keyword%3D%22{query}%22',
    // Custom result list locator to parse the results out of the YQL response.
    // This is necessary because YQL sometimes returns an array of results, and
    // sometimes just a single result that isn't in an array.
    resultListLocator: function (response) {
      var results = response[0].query.results &&
            response[0].query.results.Artist;
      if (results && !Y.Lang.isArray(results)) {
        results = [results];
      }
      return results || [];
    }
  });
});
Complete Example Source
<div id="demo" class="yui3-skin-sam"> <!-- You need this skin class -->
  <label for="ac-input">Music artist:</label><br>
  <input id="ac-input" type="text">
</div>
<script>
YUI().use('autocomplete', 'autocomplete-highlighters', 'datasource-get', function (Y) {
  // Create a DataSource instance.
  var ds = new Y.DataSource.Get({
    source: 'http://query.yahooapis.com/v1/public/yql?format=json'
  });
  Y.one('#ac-input').plug(Y.Plugin.AutoComplete, {
    maxResults: 10,
    resultHighlighter: 'wordMatch',
    resultTextLocator: 'name',
    // Use the DataSource instance as the result source.
    source: ds,
    // YQL query to use for each request (URL-encoded, except for the
    // {query} placeholder). This will be appended to the URL that was supplied
    // to the DataSource's "source" config above.
    requestTemplate: '&q=select%20*%20from%20music.artist.search%20where%20keyword%3D%22{query}%22',
    // Custom result list locator to parse the results out of the YQL response.
    // This is necessary because YQL sometimes returns an array of results, and
    // sometimes just a single result that isn't in an array.
    resultListLocator: function (response) {
      var results = response[0].query.results &&
            response[0].query.results.Artist;
      if (results && !Y.Lang.isArray(results)) {
        results = [results];
      }
      return results || [];
    }
  });
});
</script>
