Cannot add custom customer attribute

Question

I have created a simple module that should add a custom attribute Display Name to customers but when i add this to my site i get no attribute show up. The module is correctly setup and enabled

I've looked in the eav_attribute table in the database and theres no record of it. Cache has been flushed before and after

etc/config.xml

<?xml version="1.0" encoding="UTF-8"?>
<config>
  <modules>
    <Namespace_Module>
      <version>0.0.1</version>
    </Namespace_Module>
  </modules>
    <global>
      <resources>
          <module_setup>
            <setup>
              <module>Namespace_Module</module>
              <class>Mage_Eav_Model_Entity_Setup</class>
            </setup>
            <connection>
              <use>default_setup</use>
            </connection>
          </module_setup>
      </resources>
    </global>
</config>

sql/module_setup/mysql4-install-0.0.1.php

<?php
$installer = $this;
$installer->startSetup();
$customerEntityTypeId = $installer->getEntityTypeId('customer');
$atttributeCode = 'display_name';

$installer->removeAttribute($customerEntityTypeId, $atttributeCode );
$installer->addAttribute('customer', $atttributeCode, array(
    'type' => 'varchar',
    'input' => 'text',
    'label' => 'Display Name',
    'global' => true,
    'visible' => true,
    'required' => false,
    'user_defined' => true,
    'visible_on_front' => true
));

$usedInCustomerAddressForms = array(
    'adminhtml_customer',
    'customer_account_edit'
);
$attribute = Mage::getSingleton('eav/config')->getAttribute('customer', $attributeCode);
$attribute->setData('used_in_forms', $usedInCustomerAddressForms);
$attribute->save();
$this->endSetup();

Answer 1

The first param of addAttribute() should not be the string "customer", it should be the entity type id, which you already have in $customerEntityTypeId.

The same for the function getAttribute().

So change

$installer->addAttribute('customer', $atttributeCode, array(

to

$installer->addAttribute($customerEntityTypeId, $atttributeCode, array(

and change

$attribute = Mage::getSingleton('eav/config')->getAttribute('customer', $attributeCode);

to

$attribute = Mage::getSingleton('eav/config')->getAttribute($customerEntityTypeId, $attributeCode);

Answer 2

Your resource setup seems to be wrong.

  <resources>
      <module_setup>
        <setup>
          <module>Namespace_Module</module>
          <class>Namespace_Module_Model_Resource_Setup</class>
        </setup>
        <connection>
          <use>default_setup</use>
        </connection>
      </module_setup>
  </resources>

See the class node. You were using Mage_Eav_Model_Entity_Setup and it is wrong. If you are planning to use your Magento's default resource setup, then you don't want to define this part. Setting up a resource setup for a custom module allows us more power than rely on default setup resource. If you are planning to use your own resource setup, then it is essential to define setup class. It should look like this.

<?php
class Namespace_Module_Model_Resource_Setup extends Mage_Eav_Model_Entity_Setup {
} 

However I don't think, this is the real cause of your issue. But I need to point out this because, according to me, this part seems wrong.

Workaround

You can do a small workaround to find the issue. It is sure that the problem inside installer script. So what you need to do is, delete the entry that corresponds for your module from core_resource table. This will make Magento again execute the installer file. Put a die() statement in the installer file and analyze each and every item inside that file by printing out it.

There is an excellent tutorial for this. Try to follow this This