CAutoComplete

protected function getClientOptions()
{
    static $properties=array(
        'minChars', 'delay', 'cacheLength', 'matchSubset',
        'matchCase', 'matchContains', 'mustMatch', 'selectFirst',
        'extraParams', 'multiple', 'multipleSeparator', 'width',
        'autoFill', 'max', 'scroll', 'scrollHeight', 'inputClass',
        'formatItem', 'formatMatch', 'formatResult', 'highlight',
        'resultsClass', 'loadingClass');
    static $functions=array('formatItem', 'formatMatch', 'formatResult', 'highlight');

    $options=$this->options;
    foreach($properties as $property)
    {
        if($this->$property!==null)
            $options[$property]=$this->$property;
    }
    foreach($functions as $func)
    {
        if(is_string($this->$func) && strncmp($this->$func,'js:',3))
            $options[$func]='js:'.$this->$func;
    }

    return $options;
}

public function init()
{
    list($name,$id)=$this->resolveNameID();
    if(isset($this->htmlOptions['id']))
        $id=$this->htmlOptions['id'];
    else
        $this->htmlOptions['id']=$id;
    if(isset($this->htmlOptions['name']))
        $name=$this->htmlOptions['name'];

    $this->registerClientScript();

    if($this->hasModel())
    {
        $field=$this->textArea ? 'activeTextArea' : 'activeTextField';
        echo CHtml::$field($this->model,$this->attribute,$this->htmlOptions);
    }
    else
    {
        $field=$this->textArea ? 'textArea' : 'textField';
        echo CHtml::$field($name,$this->value,$this->htmlOptions);
    }
}

public function registerClientScript()
{
    $id=$this->htmlOptions['id'];

    $acOptions=$this->getClientOptions();
    $options=$acOptions===array()?'{}' : CJavaScript::encode($acOptions);

    $cs=Yii::app()->getClientScript();
    $cs->registerCoreScript('autocomplete');
    if($this->data!==null)
        $data=CJavaScript::encode($this->data);
    else
    {
        $url=CHtml::normalizeUrl($this->url);
        $data='"'.$url.'"';
    }
    $cs->registerScript('Yii.CAutoComplete#'.$id,"jQuery(\"#{$id}\").legacyautocomplete($data,{$options}){$this->methodChain};");

    if($this->cssFile!==false)
        self::registerCssFile($this->cssFile);
}

public static function registerCssFile($url=null)
{
    $cs=Yii::app()->getClientScript();
    if($url===null)
        $url=$cs->getCoreScriptUrl().'/autocomplete/jquery.autocomplete.css';
    $cs->registerCssFile($url);
}