Club Drupal

Drupal module: Variable API

===========================

Variable module will provide a registry for meta-data about Drupal variables.

Module Developers: Please declare your variables.

Why?

====

- So other modules can know about your module's variables and they can be translated, exported, etc.

- You'll get automatic variable edit forms, tokens, access control and uninstall for free. 

How?

====

Easy: Implement hook_variable_info();

/**

 * Implements hook_variable_info().

 */

function mymodule_variable_info($options) {

  $variable['mymodule_number'] = array(

    'title' => t('Magic number', array(), $options),

    'description' => t('Magic number, array(), $options),

    'type' => 'number',

    'access' => 'administer menus',

  );

  $variable['mymodule_name'] = array(

    'title' => t('Name', array(), $options),

    'description' => t('Enter your name, please.', array(), $options),

    'type' => 'string',

    'default' => t('Drupal user', array(), $options),

  );

  $variable['mymodule_mail'] = array(

    'title' => t('Mail'),

    'type' => 'mail_text',

    // This type will spawn into two real variables: mymodule_mail_subject, mymodule_mail_body

    // Everything, included the form elements, will be handled automatically

  );

  return $variable;

}  

Note: You can have your variables declared in a separate file that just will be loaded when needed.

      yourmodule.variable.inc

FAQ

===

- Will I need to add a dependency on the variable.module?

  Not neccessarily. Just if you want to enjoy some of the module's features advanced features like:

  - Getting variable values or defaults in different languages. Use variable_get_value().

  - Let other modules alter my variable defaults. Implement hook_variable_info_alter().

  - Let other modules know when variables are changed. Use variable_set_value(). Implement hook_variable_update().

  - Getting automatic forms for all the module's variables, a group of variables, etc..

  - Having variables with multiple values handled automatically like mail body and subject or variables for node types.

  Otherwise you can just provide the meta-data for other modules to use. You still get:

  - Tokens for your variables like [variable:myvariable_name]

  - Variables deleted automatically when the module is uninstalled

  - Localizable texts for your variables when using the Internationalization module.

- How do I get a form with all of my module's variables?

  drupal_get_form('variable_module_form', 'mymodule');

- Once I have declared a default for my variable, how can I benefit from it?

  variable_get_value('variable_name');

- What if I don't want to provide any administration form for my variables?

  That's ok, people will still be able to see and edit them by enabling the 'Variable Admin' module included.