Dynamic Dropdown in yii - php

Question

I followed the instructions given in the wiki in creating dynamic dropdowns in yii but still the second dropdown doesnt generate,
here is my view file:
echo CHtml::dropDownList('AccountTypeID','', array(1=>'Admin',2=>'Manager',3=>'Business',4=>'Finance',5=>'Customer Support'),array('ajax' => array('type'=>'POST',
'url'=>CController::createUrl('currentController/dynamiccities'), //url to call.
'update'=>'#city_id', //selector to update
)));
echo CHtml::dropDownList('city_id','', array());
and here is my controller:
public function actionDynamiccities(){
$data= RefAccountgroup::model()->findAll('parent_id=:parent_id',
array(':parent_id'=>(int) $_POST['AccountTypeID']));
$data=CHtml::listData($data,'AccountGroupID','AccountGroupName');
foreach($data as $value=>$name)
{
echo CHtml::tag('option',
array('value'=>$value),CHtml::encode($name),true);
}}

Answer 1

Please pay attention on the 'ajax' declaration
'ajax' => array(
'type'=>'POST',
'url'=>CController::createUrl('currentController/dynamiccities'), //url to call.
'update'=>'#city_id', //remember to change it according to this rules #modelname_columnname
'data'=>array('AccountTypeID'=>'js:this.value'), //I think you missed this line
)));
If you have firebug installed on your firefox browser, try to look up at the console tab, and check whether your dropdownlist change successfully sent out parameter AccountTypeID and you can see the responses as well.

Answer 2

First things first, your question would have been improved if you actually included the link to what tutorial you tried to follow.
Second, when answering the question in the comment, "It didn't sent a data" doesn't really clarify anything. At this point, I'm not sure if you even looked in Firebug or any web developer tool to inspect what was being posted and what was being received. My guess is that if you would have looked you would have seen a POST request being made, with no data being sent, and no data being returned.
Your AJAX call doesn't have a data parameter, so $_POST['AccountTypeID'] will not be defined, meaning that $data in your controller will be empty as well.
Update your AJAX to POST the AccountTypeID, e.g.:
echo CHtml::dropDownList('AccountTypeID',
'',
array(1=>'Admin',2=>'Manager',3=>'Business',4=>'Finance',5=>'Customer Support'),
array('ajax' => array('type'=>'POST',
'url'=>CController::createUrl('currentController/dynamiccities'), //url to call.
'update'=>'#city_id', //selector to update
'data'=> '$("#AccountTypeID").serialize()',
)));
echo CHtml::dropDownList('city_id','', array());
You may need to adjust the data parameter to properly parse the correct input to get the AccountTypeID - I'm just guessing in my sample code above.
Then, while testing, make sure to use Firebug or similar to inspect what's getting POST'ed and make sure that you have AccountTypeID being passed.

Answer 3

Is simple. You need to declare a public variable on your model with the same name as the dropdownlist. Ex.
in your model
public mydropdown;
in your view
echo $form->dropDownList($model, 'mydropdown',array('1'=>'hello','2'=>'bye'));

Answer 4

Not sure if this helps, but...
echo CHtml::dropDownList('city_id','', array( 'id' => 'city_id' ));