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.