Magento Helper – Referencing a Helper Class in Magento

helpermodule

I am trying to write a helper class for my module. The helper class will provide two methods with various functionality. Can I put this helper class beside the other helper class in my …/Helper/Data.php file or should I put it somewhere else? Also, how should I reference it from other parts of Magento in order to get access to its methods?

Best Answer

You can create as many helpers as you want in your module.
Let's say your module name is Namespace_Module.
The config.xml of your module should contain this inside the <global> tag:

<helpers>
    <module>
       <class>Namespace_Module_Helper</class>
    </module>
</helpers>

Now let's say you want to create a helper called Something.
You should place the code in Namespace/Module/Helper/Something.php:

<?php 
class Namespace_Module_Helper_Something extends Mage_Core_Helper_Abstract { //or any other helper

    public function doSomething(){
        ....
    }
}

You can call your new helper anywhere like this:

Mage::helper('module/something')->doSomething();

Basically Mage::helper('module'); is the same thing as Mage::helper('module/data');

Related Solutions

Magento – checkout Helper Url overload not working

I'm on my phone so I can't search for you, but you need to determine if the class is being invoked directly i.e. new Mage_Checkout_Helper_Url or if another class is extending it. That's the only way this rewrite won't work.

Magento – How to Extend Multiple Classes from a Single Helper

As far as I know, this is not at all possible with magento. Basically what you need is to inherit your class from HelperA (of module A) and HelperB (of module B).

In php, you cannot extend a class from two base classes

So if you really need to extend from HelperA and HelperB at the same time, then the best shot would be..

Extend your your Helper from HelperA and then rewrite HelperA class in such a way that it extends from HelperB instead of default base class Mage_Core_Helper_Abstract

Extend your your Helper from HelperB and then rewrite HelperB class in such a way that it extends from HelperA instead of default base class Mage_Core_Helper_Abstract.

This way your Helper will extend from both HelperA and HelperB. Which method should opt in this case is purely depends upon your application. So choose the right option. Here I am going to show you how to do the first implementation.

File : app/code/local/Namespace/Module/etc/config.xml

<config>
    <global>
        <helpers>
            <!-- your module's helper definition -->
            <namespace_module>
                <class>Namespace_Module_Helper_Data</class>
            </namespace_module>

            <!-- this part rewrites helperA class -->
            <helperA_alias_name>
                <rewrite>
                    <data>Namspace_Module_Helper_Rewrite_NamespaceA_ModuleA_Helper_Data</data>
                </rewrite>
            </helperA_alias_name>
        </helpers>
    </global>
</config>

File : app/code/local/Namespace/Module/Helper/Data.php

<?php
class Namespace_Module_Helper_Data 
    extends Namspace_Module_Helper_Rewrite_NamespaceA_ModuleA_Helper_Data
{
    //your helper method should come here.
}

File : app/code/local/Namespace/Module/Helper/Rewrite/NamespaceA/ModuleA/Helper/Data.php

<?php
class Namspace_Module_Helper_Rewrite_NamespaceA_ModuleA_Helper_Data
    extends NamespaceB_ModuleB_Helper_Data
{
    //you need to paste every single method of HelperB here.
}

Explanation

Here Namespace_Module stands for your module. NamespaceA_ModuleA stands for MODULE A and NamespaceB_ModuleB stands for MODULE B.

Your module's config.xml file holds two important definitions. First it defines your modules helper class Namespace_Module_Helper_Data. Secondly, it rewrites HelperA with a custom class Namspace_Module_Helper_Rewrite_NamespaceA_ModuleA_Helper_Data. This way magento will use Namspace_Module_Helper_Rewrite_NamespaceA_ModuleA_Helper_Data class when a request for helper class of MODULE A get processed.

Now see the class definitions. Firstly, your helper class extends Namspace_Module_Helper_Rewrite_NamespaceA_ModuleA_Helper_Data. This means your class is now inheriting Helper A. Secondly Namspace_Module_Helper_Rewrite_NamespaceA_ModuleA_Helper_Data extends from HelperB. Due to this now your helper class inherit from HelperB too.

ie Your helper class inherits from HelperA which then inherits from HelperB.

This is purely theory. I didn't try this before. But it seems really logical for me.

Note 1 : Use this approach only in the case, if you really want to define only one class which should extend from two base classes. Otherwise you can go for @Rick Method.

Note 2 : For the proper working of your module, you need to make sure two things here. First, your module should load only after MODULE A and MODULE B. Second, MODULE B should load before MODULE A. That is the order of loading should be..

  MODULE B - first
  MODULE A - second
  YOUR MODULE - third

Good luck

Best Answer

Related Solutions

Magento – checkout Helper Url overload not working

Magento – How to Extend Multiple Classes from a Single Helper

Explanation

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