Magento Product Attribute Setup Installer - Add New Product Attribute & Add to All Attribute Sets to Specified Group - Full List of available params used for catalog_product addAttribute installation

config.xml

filepath: My/Module/etc/
<?xml version="1.0"?>
<config>
    <modules>
        <My_Module>
            <version>0.0.1</version>
        </My_Module>
    </modules>
    <global>
        <resources>
            <unique_resource_name>
                <setup>
                    <module>My_Module</module>
                    <class>Mage_Catalog_Model_Resource_Setup</class>
                </setup>
                <connection>
                    <use>core_setup</use>
                </connection>
            </unique_resource_name>
            <unique_resource_name>
                <connection>
                    <use>core_write</use>
                </connection>
            </unique_resource_name>
            <unique_resource_name>
                <connection>
                    <use>core_read</use>
                </connection>
            </unique_resource_name>
        </resources>
    </global>
</config>

for-category_mysql4-install-0.0.1.php

<?php
/**
 * Product Attribute Installer
 */

/* @var $installer Mage_Catalog_Model_Resource_Setup */
$installer = $this;
$installer->startSetup();

$installer->addAttribute(Mage_Catalog_Model_Category::ENTITY, 'new_attribute', array(
    'group' => 'Display Settings', ///the tab group it belongs to
    'input' => 'select', //input type
    'type' => 'int', //db type
    'label' => 'Show Simple Products Only', //backend label
    'source' => 'eav/entity_attribute_source_boolean', //source for options if needed, else empty/null it
    'global' => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_STORE, // scope to store or ::GLOBAL
    'backend' => '', //backend model if needed for options, otherwise we leave empty/null
    'wysiwyg_enabled' => 0, //no we hate this
    'visible_on_front' => 1, //include in collection data
    'is_html_allowed_on_front' => 0, //not sure if this is required or not, seems the table is shared with product attributes that use this
    'visible' => 1, //is visible 
    'required' => 0, //is required?
    'user_defined' => 1, //user defined yes
    'default' => '0', //default value - I am using a select int dropdown (yes/no) bool, so I'm defaulting to No(0).
));

$installer->endSetup();

for-products_mysql4-install-0.0.1.php

filepath: My/Module/sql/unique_resource_name/
<?php
/**
 * Product Attribute Installer
 */

/* @var $installer Mage_Catalog_Model_Resource_Setup */

$code = 'new_attribute_code';

$installer = $this;
$installer->startSetup();

// Add new attribute `size`
$installer->addAttribute(Mage_Catalog_Model_Product::ENTITY, $code, array(
    'label' => 'MyLabel',             // Default label
    'input' => 'text',           // Input type (text, textarea, select...)
    'type' => 'varchar',              // Attribute type (varchar, text, int, decimal...)
    'required' => false,              // Is the attribute mandatory?
    'comparable' => false,               // Is the attribute comparable? (on frontend).
    'filterable' => false,               // Is the attribute filterable? (on frontend, in category view)
    'filterable_in_search' => false,               // Is the attribute filterable? (on frontend, in search view)
    'used_for_promo_rules' => false,               // Do we need that attribute for specific promo rules?
    'global' => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_STORE, // Attribute scope
    'is_configurable' => false,               // Can the attribute be used to create configurable products?
    'is_html_allowed_on_front' => false,              // Is HTML allowed on frontend?
    'note' => '',                 // Note below the input field on admin area
    'searchable' => false,               // Is the attribute searchable?
    'unique' => false,              // Must attribute values be unique?
    'used_for_sort_by' => false,              // Can the attribute be used for the 'sort by' select on catalog/search views?
    'used_in_product_listing' => false,               // Attribute value included in product model for catalog listing
    'user_defined' => true,               // Is the attribute user defined? If false the attribute isn't removable. TRUE needed if configurable attribute.
    'visible' => true,               // Is the attribute visible? If true the field appears in admin product page.
    'visible_on_front' => true,               // Is the attribute visible on front?
    'visible_in_advanced_search' => false,               // Is the attribute visible on advanced search?
    'wysiwyg_enabled' => false              // Is Wysiwyg enabled? (use `textarea` input if you put that value to true)
));

//add to all available attribute_sets, to specified group 
$entityId = Mage::getModel('eav/entity_type')->getCollection()->addFieldToFilter('entity_type_code', 'catalog_product')->getFirstItem()->getId();
$collection = Mage::getResourceModel('eav/entity_attribute_set_collection')->setEntityTypeFilter($entityId);

foreach ($collection as $attrs):
    $installer->addAttributeToSet(
        Mage_Catalog_Model_Product::ENTITY,   // Entity type
        $attrs->getAttributeSetId(),                            // Attribute set name
        'Product Details',                            // specified Attribute set group name you want to add to
        $code,                  // Attribute code to add
        5                                   // Position on the attribute set group
    );
endforeach;

$installer->endSetup();

My_Module.xml

filepath: app/etc/modules/
<?xml version="1.0"?>
<config>
    <modules>
        <My_Module>
            <active>true</active>
            <codePool>local</codePool>
        </My_Module>
    </modules>
</config>