This example demonstrates how to provide autocomplete suggestions using a YQL query as the source. In this case, we're using a custom search.suggest YQL table to provide suggestions based on popular Yahoo! Search queries.
HTML
<div id="demo" class="yui3-skin-sam"> <label for="ac-input">Search:</label><br> <input id="ac-input" type="text"> </div>
JavaScript
YUI().use('autocomplete', 'autocomplete-highlighters', function (Y) {
  Y.one('#ac-input').plug(Y.Plugin.AutoComplete, {
    resultHighlighter: 'phraseMatch',
    source: 'select * from search.suggest where query="{query}"',
    yqlEnv: 'http://pieisgood.org/yql/tables.env'
  });
});
Complete Example Source
<div id="demo" class="yui3-skin-sam">
  <label for="ac-input">Search:</label><br>
  <input id="ac-input" type="text">
</div>
<script>
YUI().use('autocomplete', 'autocomplete-highlighters', function (Y) {
  Y.one('#ac-input').plug(Y.Plugin.AutoComplete, {
    resultHighlighter: 'phraseMatch',
    source: 'select * from search.suggest where query="{query}"',
    yqlEnv: 'http://pieisgood.org/yql/tables.env'
  });
});
</script>