Hooks Class¶

Hooks allows you to dynamically change or add functionality without changing Vesthelm Engine core files.

In Vesthelm Engine there are two types of hooks: controller and dynamic

Controller Hook - Use when you do not need to modify variables values in a file or class!!!
Advantages: easier debugging, do not need to edit database table to change hook - hook code stored in a file.
Disadvantages: less functionality than dynamic hook - can not modify variables values
- Creating a Controller Hook
- Anatomy of a Controller Hook
Dynamic Hook - Use when you need to modify variables values in a file or class!!!
Advantages: powerful
Disadvantages: to change hook code need to edit database table, hard debugging - using eval()
- Creating a Dynamic Hook
Calling a Hook

Creating a Controller Hook¶

Let's say you want to assign variable to bulletin board application template. So you will use hook AfterRegisterFunctions defined in includes/smarty.php

defined('V_IN_FRONTEND') or die('Powered by <a href="http://www.vesthelm.com/">Vesthelm EE</a>');

class Bulletin_Board_AfterRegisterFunctions_Hook extends Vesthelm_Hook_Controller {

    public function execute() {
        var_dump('Testing Controller Hook');
    }

    public function init() {
        $this->_initBulletins();
    }

    public function assign() {
        $this->_assignBulletins();
    }

    protected function _initBulletins() {
        $this->sponsored_bulletins = $this->bulletin_board->Bulletin->getBulletins();
    }

    protected function _assignBulletins() {
        if (!empty($this->sponsored_bulletins)) {
            $this->View->assign("sponsored_bulletins", $this->sponsored_bulletins);
        }
    }

}

And now in your template files you can use $sponsored_bulletins variable:

{if $sponsored_bulletins}
    {foreach from=$sponsored_bulletins item=bulletin name="bulletins"}
        {$bulletin.description}
    {/foreach}
{/if}

Anatomy of a Controller Hook¶

Controller Hooks classes are stored in folders:

//Core hooks
example.com/frontend/hooks
example.com/acp/hooks

//Application hooks
example.com/applications/{application_name}/frontend/hooks
example.com/applications/{application_name}/acp/hooks

//Addon hooks
example.com/addons/{addon_name}/frontend/hooks
example.com/addons/{addon_name}/acp/hooks

The basic prototype for a hook class is:

class Enhancement_Name_Hook_Name_Hook extends Vesthelm_Hook_Controller {
    public function execute() {        
    }
}

Where Enhancement_Name is the name of your enhancement. Enhancement names must have the first letter capitalized after underscore _ character.

Where Hook_Name is the name of your class. Class names must have the first letter capitalized after underscore _ character.

The file name will be same as your class name (Hook_Name). For example, if your class is:

class Bulletin_Board_AfterRegisterFunctions_Hook extends Vesthelm_Hook_Controller {
    public function execute() {        
    }
}

Your file will be:

applications/bulletin_board/acp/hooks/AfterRegisterFunctions.php

Creating a Dynamic Hook¶

Dynamic Hooks evaluated by PHP eval()

Let's say you want to unset variable $enhancements in a file includes/smarty.php. So you will use hook AfterRegisterFunctions and add following code to database table hooks:

global $enhancements;

$enhancements = null;

MySQL query:

INSERT INTO `{your_table_prefix}_hooks` (`id`, `enh`, `file`, `name`, `value`, `code`, `status`, `enhancement`, `side`, `u_id`, `order`) VALUES
(NULL, '', 'index', 'AfterRegisterFunctions', 'global $enhancements;

$enhancements = null;', 'php', 'active', '', 'frontend', '', 0);

Calling a Hook¶

To call hook in a file:

call_hook('hookName', 'enhancement_name', 'file_name');

Where hookName is the name of your hook.

Where enhancement_name is the name of your enhancement. (if empty value specified will try to use V_APPLICATION or V_ADDON constant)

Where file_name is the name of your file where you adding call_hook() function. (if empty value specified will try to use V_REALM constant)