Difference between #3 and #4 of Working with radiobutton list

This isI am a tutorial to work with radioButtonList
which will handle enum datatype. 
Form design and validation both are detailed here. 

Trynewbie, i thought my code may help some one. 
Try this and let me know if here is any issueerror
or any other better way to do this.

Scenario:
---------
Let we have enum for table field menuType as shown below.

- menuType : enum('Page','PhpPage','External')

- pageId: int (If menuType is 'Page')

- phpPageId: int (If menuType is 'PhpPage')

- externalLink: varchar (If menuType is 'External')


Form elements:
--------------

Now in form, based on menu type selection i want to show or hide other 3 fields.
The below code will take care of it. 
I have called 'menuTypeChange' function on change of any radio selection. This
function will show/hide respected elements.


~~~
[php]
<script language="javascript">
function menuTypeChange(menyType)
{	
	$('.menuType').hide();
	if(menyType!="")
		$('#'+menyType+'Div').show();
}
</script>
<div class="row">
		<?php echo $form->labelEx($model,'menuType'); ?>
        <?php echo
$form->radioButtonList($model,'menuType',array('Page'=>'Page','PhpPage'=>'PHP
Page', 'External'=>'External'), array('onchange' =>
'menuTypeChange(this.value);')); ?>
        <?php echo $form->error($model,'menuType'); ?>
    </div>
    
	<div id="PageDiv" class="row menuType">
		<?php echo $form->labelEx($model,'pageId'); ?>
        <?php echo $form->dropDownList($model, 'pageId',
CHtml::listData(Page::model()->findAll(array('condition'=>'isDeleted=:isDeleted',
'params'=>array(':isDeleted'=>0))), 'pageId', 'pageName'),
array('empty'=>'- - Select - -')); ?>      
		<?php echo $form->error($model,'pageId'); ?>
	</div>
    
    <div id="PhpPageDiv" class="row menuType">
		<?php echo $form->labelEx($model,'phpPageId'); ?>
        <?php echo $form->dropDownList($model, 'phpPageId',
CHtml::listData(PhpPage::model()->findAll(), 'phpPageId', 'phpPageName'),
array('empty'=>'- - Select - -')); ?>      
		<?php echo $form->error($model,'phpPageId'); ?>
	</div>

	<div id="ExternalDiv" class="row menuType">
		<?php echo $form->labelEx($model,'externalLink'); ?>
		<?php echo
$form->textField($model,'externalLink',array('size'=>60,'maxlength'=>255));
?>
		<?php echo $form->error($model,'externalLink'); ?>
	</div>
<script language="javascript">
    menuTypeChange('<?php echo $model->menuType;?>');
	</script>
~~~
I have done with form. Now the problem is validation.

How validation works?
---------------------

With default rules when i submit form it is asking me all 3 fields validation
even i have selected only one menu type.
For this let me create one new custom validation function as shown below.
~~~
[php]
public function rules()
  return array(
  ....
  ....
   array('menuType', 'required'),
    array('pageId','radioValidate','menuType','Page'),
    array('phpPageId','radioValidate','menuType','PhpPage'),
    array('externalLink','radioValidate','menuType','External'),
    array('externalLink', 'url'),
  ....
  );
}
public function radioValidate($attribute,$params)
{
	$field = $params[0];
	$value = $params[1];
	
	if($this->$field == $value && $this->$attribute == '')
	{
		$this->addError($attribute,$this->getAttributeLabel($attribute).' cannot
be blank.');
	}
}
~~~


Let me explain more on this rule:


~~~
[php]
array('pageId','radioValidate','menuType','Page'),
~~~

Above rule means: 
If **menuType**'s value is **Page** then only **pageId** is compulsory.

Same goes with other too,


~~~
[php]
array('phpPageId','radioValidate','menuType','PhpPage'),
array('externalLink','radioValidate','menuType','External'),
~~~