Creating a drupal module

It’s amazing – I’ve worked on dozens of Drupal projects (as far back as 4.7) as a PM, and never actually built a module myself. Wow. Now I’m going to have to learn!

Contents 1 Guides 2 Howto: block function 2.1 Configuration form 3 Permissions for custom pages 4 create page (private) view 5 Notes on function names 6 Creating a module action

Guides

• Learn how to create a module from scratch!: http://drupal.org/node/1074362
• Configure your fave text editor to do syntax highlighting with Drupal’s non-standard filenames: http://drupal.org/node/29325

Howto: block function

• name it: give it a lowercase_underscore type name for module file name and function prefixes (make sure it’s not an existing theme name)
• create folder and module file sites/all/modules/module_name/module_name.module
• create module_name.info file
• add module @file comment description
• add a help hook: module_name_help function (returns text and breaks)
• if it’s a block hook, add module_name_block_info (describe it to Drupal) : info, cache etc.
• add content functions (get things from db. etc)
• if it’s a block module: do a block view
  • use a switch($delta) – you might want more blocks later in the same module
  • do access checks – on content retrieval functions
  • do the db grab function to get stuff in a result
  • load up the $items array with a foreach loop
  • if it’s empty – return an apology
  • otherwise: pass data (as $items array) through ot the template function – choosing a format (lists etc… or whatever)
  • return the block

Configuration form

• Impement a hook_menu function (module_name_menu) – to create a configuration form for the module
  • do not t(translate) it (automatically translated by drupal) – pass it an array of title, description, page callback (drupal_get_form), page arguments (current_posts_form – see below), access arguments and type.
  • Then return items.
• now do the current_posts_form
  • use #variables and check the forms api reference for element attributes you can set.
  • variable_get(thing, def.val) to get/set default persistent variable (indexed on form name)
  • system_settings_form calls Drupal’s form api to do the work. (you don’t have to create a submit button… although we could if we wanted)
• now do any necessary data validation
  • use &$form_state to capture and keep $_POST variables during form process
  • use ifs to validate values from the $form_state array

 

Permissions for custom pages

• create module_name_permission hook
• create private page callback hook
• add $display variable to module_name_contents() function
  • this will enable block or page view

create page (private) view

• use private function call for module_name_page hook
• load items into array with module_name_contents hook (+display variable ‘page’)
• add a ‘if no data’ option & return the page array
• else, return page array *with double underscore after theme tag*
• eg: item_list__module_name (this enables specific theming options by telling Drupal it’s a theme hook suggestion)

Notes on function names

• private: _module_name_functionname
• public: module_name_functionname
• always check your function name isn’t the same as a hook name
• if you’re implementing a hook: module_name_hookname
• NB: page callbacks (very specific to module) are a good candidate for private

 

Creating a module action

• first define the action using hook_actions_info
• then create action functions module_name_description_of_action_action
• optional form definition