Add a link to Magento's My Account Page Conditionally

I would like to create a link on the My Account page that only get displays under certain conditions.

Right now I have the link display all the time by adding the following entry to my layout XML file:

<customer_account>
    <reference name="customer_account_navigation">
        <action method="addLink" translate="label" module="nie"><name>nie</name><path>nie</path><label>NIE Admin</label></action>
    </reference>
</customer_account>

I am assuming there is a way to code this so that it only displays under certain 开发者_开发百科circumstances.

The cart & checkout links already do something similar so their method can be copied.

1. Create a block. It won't be displaying directly so can be descended from the boring Mage_Core_Block_Abstract.

2. Give it a method where the conditional logic will go.

   public function addNieLink()
   {
       if (($parentBlock = $this->getParentBlock()) && (CONDITION-GOES-HERE)) {
           $parentBlock->addLink($this->_('NIE Admin'), 'nie', $this->_('NIE Admin'), true, array(), 50, null, 'class="top-link-cart"');
           // see Mage_Page_Block_Template_Links::addLink()
       }
   }
   
   protected function _prepareLayout()
   {
       // Add the special link automatically
       $this->addNieLink();
       return parent::_prepareLayout();
   }
   

   Put your check in place of CONDITION-GOES-HERE.

3. Add your block to the links block.

   <customer_account>
       <reference name="customer_account_navigation">
           <block type="yourmodule/link" name="yourmodule.link" />
       </reference>
   </customer_account>
   

   (Correct the block type here to your newly created link block)

The important bit is it calls getParentBlock() to find out where the link is to go.