Rewrite for third party module's model not working

Question

By using the third party module, There is a option in admin configuration side to select the number of columns for the catalog page. I want to add an additional column option in the admin configuration side.

In third party module Model/Columncount.php

    <?php class Third_Party_Model_Columncount
    {
        public function toOptionArray()
        {
            return array(
  array('value'=>'3', 'label'=>Mage::helper('ThemeConfig')->__('3 Column Grid')),
  array('value'=>'4', 'label'=>Mage::helper('ThemeConfig')->__('4 Column Grid')),
  array('value'=>'5', 'label'=>Mage::helper('ThemeConfig')->__('5 Column Grid'))
                );
    }
    ?>

I need to add one more option with it,

For that I made an module to rewrite model as below

My_Module.xml

<config>
  <modules>
    <My_Module>
        <active>true</active>
        <codePool>local</codePool>
        <depends><Third_Party/></depends>
    </My_Module>
  </modules>
</config>

in the My/Module/etc/config.xml

<config>
    <modules>
      <My_Module>
       <version>0.1.0</version>
      </My_Module>
    </modules>
    <global>
        <models>
        <module>
        <class>My_Module_Model</class>
        </module>
            <party>
                <rewrite>
                    <columncount>My_Module_Model_Columncount</columncount>
                </rewrite>
            </party>
        </models>
    </global>
</config>

and in My/Module/Model/Columncount.php

<?php class My_Module_Model_Columncount extends Third_Party_Model_Columncount
{
    public function toOptionArray()
    {
        return array(
        array('value'=>'3', 'label'=>Mage::helper('ThemeConfig')->__('3 Column Grid')),
        array('value'=>'4', 'label'=>Mage::helper('ThemeConfig')->__('4 Column Grid')),
        array('value'=>'5', 'label'=>Mage::helper('ThemeConfig')->__('5 Column Grid')),
        array('value'=>'6', 'label'=>Mage::helper('ThemeConfig')->__('6 Column Grid'));
    }

}?>

But it is not getting rewritten, why? Can anyone help here.

Answer 1

The rewrite is fine and should work but you do have error in config.xml file

<module>    

is repeated twice, second note should be closed

</module>  

You can try test it using

get_class(Mage::getModel('party/columncount'))

The problem might also be related to attribute / column renderer. You need to check if the model / block uses magento class prefix party/columncount to handle renderer or if the class name is put as it is Third_Party_Model_Columncount