Proposed filter_extensions hook and example

gistfile1.aw

<?php

/////////////////////////////////////////////
// Added hook call to EE_Extensions:
/////////////////////////////////////////////
class EE_Extensions {  
	... 
	function __construct()
  	{  
		$this->EE =& get_instance();
  		if ($this->EE->config->item('allow_extensions') == 'y')
  		{
  			$query = $this->EE->db->query("SELECT DISTINCT ee.* FROM exp_extensions ee WHERE enabled = 'y' ORDER BY hook, priority ASC, class");
  			if ($query->num_rows() > 0)
  			{
  				$this->extensions = array();
  				foreach($query->result_array() as $row)
  				{
					$row['class'] = ucfirst(strtolower($row['class']));
  					$this->extensions[$row['hook']][$row['priority']][$row['class']] = array($row['method'], $row['settings'], $row['version']);
  					$this->version_numbers[$row['class']] = $row['version'];
  				}
  			}
  			// Added - airways
  			if($this->active_hook('filter_extensions'))
  			{
  			    $this->extensions = $this->call('filter_extensions', $this->extensions);
  			}
  			// End Added - airways
  		}
  	}
...
}


/////////////////////////////////////////////
The extension:
/////////////////////////////////////////////


class Filter_extensions_ext {

    public $settings        = array();
    public $description     = 'Allow specifying what extensions are enabled in a config file';
    public $docs_url        = '';
    public $name            = 'Filter Extensions';
    public $settings_exist  = 'n';
    public $version         = '1.0';

    public $EE;


    public function __construct($settings = '')
    {
        $this->EE =& get_instance();
        $this->settings = $settings;
    }

    public function activate_extension()
    {
        // Setup custom settings in this array.
        $this->settings = array();

        $data = array(
            'class'     => __CLASS__,
            'method'    => 'filter_extensions',
            'hook'      => 'filter_extensions',
            'settings'  => serialize($this->settings),
            'version'   => $this->version,
            'enabled'   => 'y'
        );

        $this->EE->db->insert('extensions', $data);

    }

    public function filter_extensions($extensions)
    {
        $ext_config = $this->EE->config->item('filter_extensions');
        $disable = isset($ext_config['disable']) ? $ext_config['disable'] : array();
        
        foreach($extensions as $hook => $priority_list)
        {
            foreach($priority_list as $priority => $class_list)
            {
                foreach($class_list as $class => $call)
                {
                    if(!in_array($class, $disable))
                    {
                        $extensions_out[$hook][$priority][$class] = $call;
                    }
                }
            }
        }
        return $extensions_out;
    }

    function disable_extension()
    {
        $this->EE->db->where('class', __CLASS__);
        $this->EE->db->delete('extensions');
    }

    function update_extension($current = '')
    {
        if ($current == '' OR $current == $this->version)
        {
            return FALSE;
        }
    }
}

/* End of file ext.filter_extensions.php */
/* Location: /system/expressionengine/third_party/filter_extensions/ext.filter_extensions.php */


/////////////////////////////////////////////
// The config.php settings:
/////////////////////////////////////////////

$config['filter_extensions'] = array(
    'disable' => array('Safecracker_ext')
);