Update content in AJAX with partialRender

The easiest way to update content in AJAX is to use the partialRender method.
For this exemple I have three files: a controller (HelloWorldController.php) and two views (index.php and _ajaxContent.php)

controllers/HelloWorldController.php

class HelloWorldController extends CController
{
    public function actionIndex()
    {
        $data = array();
        $data["myValue"] = "Content loaded";
 
        $this->render('index', $data);
    }
 
    public function actionUpdateAjax()
    {
        $data = array();
        $data["myValue"] = "Content updated in AJAX";
 
        $this->renderPartial('_ajaxContent', $data, false, true);
    }
}

The actionIndex set myValue to "Content loaded" and this variable is passed to the view "index.php" and to "_ajaxContent.php"

Note: if using accessRules() in your controller file, you will need to modify accessRules() by adding the appropriate part of the function name to a rule set - in this case 'updateajax' like this:

array('allow',  // allow all users to perform 'index' and 'view' actions
    'actions'=>array('index','view','updateajax'),
    'users'=>array('*'),
        ),

views/helloWorld/index.php

<div id="data">
   php $this->renderPartial('_ajaxContent', array('myValue'=>$myValue)); ?>
div>
 
php echo CHtml::ajaxButton ("Update data",
                              CController::createUrl('helloWorld/UpdateAjax'), 
                              array('update' => '#data'));
?>

The ajaxButton call "actionUpdateAjax" and the returned data are inserted in the div "data"

views/helloWorld/_ajaxContent.php

 echo $myValue ?>

Display $myValue

Now, run index.php?r=helloWorld
Enjoy!