Can I create a module including only a helper class?

Question

Is it possible to create a module/extension with only a Helper class declared? I am trying to create a module because I need to use a function on more than one phtml files.

So far I got this code:

/app/etc/modules/Mycompanyname_CategoryStep.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Mycompanyname_CategoryStep>
            <active>true</active>
            <codePool>local</codePool>
        </Mycompanyname_CategoryStep>
    </modules>
</config>

/app/code/local/Mycompanyname/CategoryStep/Helper/Data.php

<?php
class Mycompanyname_CategoryStep_Helper_Data extends Mage_Core_Helper_Abstract
{
    public function add($num1, $num2)
    {
        return $num1 + $num2;
    }
}

/app/code/local/Mycompanyname/CategoryStep/etc/config.xml

<?xml version="1.0" encoding ="UTF-8"?>
<config>
    <modules>
        <Mycompanyname_CategoryStep>
        <version>0.1.0</version>
        </Mycompanyname_CategoryStep>
    </modules>
    <global>
        <helpers>
            <categorystep>
                <class>Mycompanyname_CategoryStep_Helper</class>
            </categorystep>
        </helpers>
    </global>
</config>

That's the error I get:

Fatal error: Class 'Mage_Categorystep_Helper_Data' not found in /home/account/public_html/app/Mage.php on line 550

Am I missing something? I followed this guide to create the module and this guide and several others to create the Helper class. Any help would be appreciated.

Answer 1

Yes you can. You need to create module xml in

in app/etc/modules/Mycompanyname_Categorystep.xml

<?xml version="1.0"?>
<config>
  <modules>
    <Mycompanyname_Categorystep>
      <active>true</active>
      <codePool>local</codePool>
      <version>0.1.0</version>
    </Mycompanyname_Categorystep>
  </modules>
</config>

Then for module main config create app/code/local/Mycompanyname/Categorystep/etc/config.xml

<?xml version="1.0"?>
<config>
  <modules>
    <Mycompanyname_Categorystep>
      <version>0.1.0</version>
    </Mycompanyname_Categorystep>
  </modules>
  <global>
    <helpers>
      <categorystep>
        <class>Mycompanyname_Categorystep_Helper</class>
      </categorystep>
    </helpers>
  </global>
</config> 

then your helper app/code/local/Mycompanyname/Categorystep/Helper/Data.php

<?php
class Mycompanyname_Categorystep_Helper_Data extends Mage_Core_Helper_Abstract
{
    //Your code here
}

The thing is, in Magento 1.9 module name's first letter should capital, but not all other. So you need to use Categorystep instead of CategoryStep