module to install attribute using setup resource

Question

I tried to create a shopping module with help, when I install the module it should add a custom attribute but for some reason it is not working

I have this structure:

config.xml is simple and just telling where to find the resource and the module name:

 <?xml version="1.0"?>
<config>
  <modules>
    <Cart_Shopping>
      <version>1.0.0</version>
      <title> Product Message</title>
    </Cart_Shopping>
  </modules>
  <global>
    <resources>
      <shop_setup>
        <setup>
          <module>Cart_Shopping</module>
          <class>Mage_Eav_Model_Entity_Setup</class>
        </setup>
        <connection>
          <use>core_setup</use>
        </connection>
      </shop_setup>
      <shop_write>
        <connection>
          <use>core_write</use>
        </connection>
      </shop_write>
    </resources>
  </global>
  <adminhtml>
    <fieldsets>
      <cart_message>
        <create>1</create>
        <update>1</update>
      </cart_message>
    </fieldsets>
  </adminhtml>
</config>

here is installer,the mysql4-install-1.0.0

$installer = Mage::getResourceModel('catalog/setup', 'catalog_setup');
Mage::log("negin", null, 'mylogfile.log');
$installer->startSetup();
$installer->addAttribute('catalog_product', 'cart_message', array(
  'type'              => 'varchar',
  'backend'           => '',
  'frontend'          => '',
  'label'             => 'Message in Cart',
  'input'             => 'select',
  'class'             => '',
  'source'            => 'catalog/product_attribute_source_layout',
  'global'            => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_STORE,
  'visible'           => true,
  'required'          => false,
  'user_defined'      => false,
  'default'           => '',
  'searchable'        => true,
  'filterable'        => false,
  'comparable'        => false,
  'visible_on_front'  => true,
  'unique'            => false,
  'group'             => 'General'
));
$installer->endSetup();

also app/etc/modules file which is reading the codepool of local:

  <config>
    <modules>
      <Cart_Shopping>
        <active>true</active>
        <codePool>local</codePool>
        <version>1.0.0</version>
      </Cart_Shopping>
    </modules>
  </config>

would you please tell me what is wrong in my configuration?

Answer 1

you config.xml should be like this. And you should have to include Namespace in your config.xml

<config>
    <modules>
        <Namespace_Shopping>
            <version>1.0.0</version>
        </Namespace_Shopping>
    </modules>
    <global>          
      <resources>
            <shop_setup>
                <setup>
                    <module>Namespace_Shopping</module>
                    <class>Mage_Eav_Model_Entity_Setup</class>
                </setup>
            </shop_setup>
       </resources>            
    </global>
</config>

make sure your main configuration file for module should be content namespace as well

Module configuration file should be as

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

EDIT

Also make sure core_resource table should not content your module version entry with 1.0.0. if it is there then your installer file wont execute.

hope, it works for you.