add attribute to admin user

Question

I need to add a field that I did to the customer, but also to the admin user. I have the customer one working,

$installer->addAttribute('customer', 'ldap_user', array(
 'type' => 'int',
 'input' => 'select',
 'source' => 'eav/entity_attribute_source_boolean',
 'label' => 'Has AD account',
 'visible' => true,
 'required' => false,
));
$attr = Mage::getSingleton( 'eav/config' )->getAttribute( 'customer', 'ldap_user' );
$attr->setData( 'used_in_forms', array( 'adminhtml_customer' ) );
$attr->save();

But I can't seem to find anything on how to do one for the admin user and all attempts so far to convert this to the admin/user model has failed. Any ideas on the correct way to add this field?

*UPDATE Base on @Marius answer I'm closer. The install part works, and the column was added. The tab prepare Form is not yes right. I put

\app\code\local\Wsu\NetworkSecurities\Block\Adminhtml\Permissions\User\Edit\Tab\Main.php

<?php
class Wsu_NetworkSecurities_Block_Adminhtml_Permissions_User_Edit_Tab_Main extends Mage_Adminhtml_Block_Permissions_User_Edit_Tab_Main {
 protected function _prepareForm() {
 parent::_prepareForm(); 
 $form = $this->getForm();
 $fieldset = $form->getElements()->searchById('user_base_fieldset');
 $fieldset->addField('ldap_user', 'select', array(
 'name' => 'is_active',
 'label' => Mage::helper('adminhtml')->__('LDAP user'),
 'id' => 'is_active',
 'title' => Mage::helper('adminhtml')->__('LDAP user'),
 'class' => 'input-select',
 'style' => 'width: 80px',
 'options' => array('1' => Mage::helper('adminhtml')->__('Yes'), '0' => Mage::helper('adminhtml')->__('No')),
 )); 
 $this->setForm($form);
 return $this;
 }
}

But I am not seeing it. I can see also I think I need to rewrite system_account/index too I would think?

/etc/config.xml

<?xml version="1.0" encoding="utf-8"?>
<config>
 <modules>
 <Wsu_NetworkSecurities>
 <version>0.1.0</version>
 </Wsu_NetworkSecurities>
 </modules>
 <global>
 <blocks>
 <wsu_networksecurities>
 <class>Wsu_NetworkSecurities_Block</class>
 </wsu_networksecurities>
 <adminhtml>
 <rewrite>
 <permissions_user_edit_tab_main>Wsu_NetworkSecurities_Block_Adminhtml_Permissions_User_Edit_Tab_Main</permissions_user_edit_tab_main>
 </rewrite>
 </adminhtml>
 </blocks>
 </global>
</config>

That is what I have for the blocks.

UPDATE

So this works to add a new fieldset and add the field, but it never could get in the main fieldset, but it works.

 protected function _prepareForm() {
 parent::_prepareForm(); 
 $form = $this->getForm();
 $fieldset = $form->addFieldset('LDAP', array(
 'legend' => Mage::helper('adminhtml')->__('User Info'),
 'class' => 'fieldset-wide'
 ));
 $fieldset->addField('ldap_user', 'select', array(
 'name' => 'is_active',
 'label' => Mage::helper('adminhtml')->__('LDAP user'),
 'id' => 'is_active',
 'title' => Mage::helper('adminhtml')->__('LDAP user'),
 'class' => 'input-select',
 'style' => 'width: 80px',
 'options' => array('1' => Mage::helper('adminhtml')->__('Yes'), '0' => Mage::helper('adminhtml')->__('No')),
 )); 
 return $this;
 }
}

• user4351: What's the config.xml for the module, especially the part that rewrites that block?
• Quantum: @Melvyn I have updated the question with the requested area.

Answer 1

You will need to add a column to the admin_user table.

$installer->getConnection()->addColumn($installer->getTable('admin/user'), 'ldap_user', array(
 'type' => Varien_Db_Ddl_Table::TYPE_TEXT,
 'length' => 256,
 'nullable' => true,
 'default' => null,
 'comment' => 'Ldap user'
)); 

Then, if you want to add/edit this field from the backend you need to rewrite the method Mage_Adminhtml_Block_Permissions_User_Edit_Tab_Main::_prepareForm and add a new element in there:

 $fieldset->addField('ldap_user', 'select', array(
 'name' => 'is_active',
 'label' => Mage::helper('adminhtml')->__('LDAP user'),
 'id' => 'is_active',
 'title' => Mage::helper('adminhtml')->__('LDAP user'),
 'class' => 'input-select',
 'style' => 'width: 80px',
 'options' => array('1' => Mage::helper('adminhtml')->__('Yes'), '0' => Mage::helper('adminhtml')->__('No')),
 )); 

Clear the cache and it should work.

• Quantum: I have updated the question to reflect your answer. I'm not quite there it seems. ideas?
• user4351: You haven't rewritten the block. It's not enough to extend the class, you need to tell Magento to use yours. I'll leave the details to @Marius.
• Quantum: so I added the rewrite to the config, although atm I'm running down why I have a fault addField() on a non-object
• Quantum: @Marius I thought this was working, but when I go to add ` $user->load($username, 'username');$user->setLdapUser(1)->save();` The value is not saving. Any idea?
• Marius: Clear the cache