Who is called a component's init() method?

Question

I'm just newbie in the Yii framework and I'm experimenting with Yii components. Let I've a simple test component:

class document extends CApplicationComponent{
        private $_width='150';
        public function init(){
            echo "This is document component init method.";
        }
        public function getWidth(){
            return $this->_width;
        }
    }

If I'm using this component in the code like the following:

Yii::import('application.components.document');
$width=Yii::app()->document->width;

then the component's init() method is invoking. Who is called this method? Can you get a refer to the line in the Yii source code on which this method is invoked.

Answer 1

From the API page for the IApplicationComponent interface which CApplicationComponent implements.

After the application completes configuration, it will invoke the init() method of every loaded application component.

After digging a little deeper this is the source code for CModule::setComponent(). CModule is the base class for all module and application classes therefore the _init will be called by your base application class.

elseif($component instanceof IApplicationComponent)
{
    $this->_components[$id]=$component;

    if(!$component->getIsInitialized())
        $component->init(); // <----

    return;
}