doc.module

<?php
/**
 * Set global array to configure core entity links
 */
$vars = array (
  '#submit_handler' => 'doc_form_alter_submit_handler',
);
 
$GLOBALS['doc_entities'] = array(
	'system_site_information_settings' => array(
		'#entity' => 'configuration',
		'#id' => 'site',
		'#submit_id' => 'site',
	)+$vars,
	'node_type_form' => array(
		'#entity' => 'content_type',
		'#fieldset' => 'additional_settings',
		'#id' => array('type','#default_value'),
		'#submit_id' => array('values','name'),
	)+$vars,
	'field_ui_field_edit_form' => array(
		'#entity' => 'field',
		'#fieldset' => 'documentation',
		'#id' => array('#field','field_name'),
		'#submit_id' => array('values','name'),
	)+$vars,
	'update_manager_install_form' => array(
		'#entity' => 'module',
		'#id' => 'module',
		'#submit_id' => 'module',
    '#submit_handler' => 'doc_module_install_create_documentation',
	),
	'taxonomy_form_vocabulary' => array(
		'#entity' => 'taxonomy',
		'#id' => array('vid','#value'),
		'#submit_id' => array('values','vid'),
	)+$vars,
	'block_add_block_form' => array(
		'#entity' => 'block',
		'#id' => array('delta','#value'),
		'#submit_id' => array('values','delta'),
	)+$vars,
	'block_admin_configure' => array(
		'#entity' => 'block',
		'#id' => array('delta','#value'),
		'#submit_id' => array('values','delta'),
	)+$vars,
	'menu_edit_menu' => array(
		'#entity' => 'menu',
		'#id' => array('menu_name','#default_value'),
		'#submit_id' => array('values','menu_name'),
	)+$vars,
	'system_theme_settings' => array(
		'#entity' => 'theme',
		'#id' => array('var','#value'),
		'#submit_id' => array('values','var'),
	)+$vars,
	'user_admin_role' => array(
		'#entity' => 'user_role',
		'#id' => array('rid','#value'),
		'#submit_id' => array('values','var'),
	)+$vars,
  'doc_module_create_documentation' => array(
		'#entity' => 'module',
		'#id' => array('#module_id'),
		'#submit_id' => array('#module_id'),
	)+$vars,
);
/**
 * Implements hook_permission().
 */
function doc_permission() {
	return array(
	'administer documentation' => array(
	'title' => t('Administer documentation'),
	'description' => t('Allow editing of documentation by user.'),
	),
	'view documentation' => array(
	'title' => t('View documentation'),
	'description' => t('Allow viewing of documentation by user.'),
	),
	);
}

/**
 * Implements hook_help().
 */
function doc_help($path, $arg) {
	switch ($path) {
		case 'admin/help#documentation':
			return t('The documentation module provides a framework for documenting all aspects of a Drupal installation');
		case 'admin/config/system/documentation':
			return t('The documentation module provides a framework for documenting all aspects of a Drupal installation');
    case 'admin/documentation/module/%':
			return t('The documentation module provides a framework for documenting all aspects of a Drupal installation');
	}
}

/**
 * Implements hook_menu().
 */
function doc_menu() {
  $access = array('view documentation');
  $administer = array('administer documentation');

	$items['admin/config/system/documentation'] = array(
		'title' => 'Documentation',
		'description' => "View the documentation for this site's implementation of Drupal.",
		'page callback' => 'drupal_get_form',
		'page arguments' => array('doc_admin_settings_form'),
		'access arguments' => $administer,
		'type' => MENU_NORMAL_ITEM,
		'file' => 'doc.admin.inc',
	);
	$items['admin/settings/documentation'] = array(
		'title' => 'Documentation',
		'description' => "View the documentation for this site's implementation of Drupal.",
		'page callback' => 'drupal_get_form',
		'page arguments' => array('doc_documentation'),
		'access arguments' => $access,
		'file' => 'doc.admin.inc',
	);
	$items['admin/settings/documentation/view'] = array(
    'title' => 'View Documentation',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -1,
  );
	$items['admin/settings/documentation/settings'] = array(
    'title' => 'Change Documentation Module Settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('customfilter_filter_add'),
    'access arguments' => $administer,
    'type' => MENU_LOCAL_TASK,
  );
	$items['admin/documentation/module/%'] = array(
		'title' => 'Create Documentation for Module',
		'page callback' => 'drupal_get_form',
		'page arguments' => array('doc_module_create_documentation',3),
		'access arguments' => $administer,
		'type' => MENU_CALLBACK,
		'file' => 'doc.admin.inc',
	);
	return $items;
}
/**
 * Implements hook_theme().
 */
function doc_theme() {
	return array_merge(drupal_common_theme(), array(
		'doc_modules' => array(
		  'render element' => 'form',
		  'file' => 'doc.admin.inc',
		),
	));
}
/**
 * Implements hook_form_alter(). Adds the documentation field to a variety of forms.
 */
function doc_form_alter(&$form, &$form_state, $form_id) {
	global $doc_entities;

	if(isset($form_id) && array_key_exists($form_id,$doc_entities) && $form['#submit'][0] != 'taxonomy_vocabulary_confirm_delete_submit' ) {
		doc_generateFields($form,$form_id);
		
		module_load_include('inc', 'doc', 'doc.admin');
		array_unshift($form['#submit'],$doc_entities[$form_id]['#submit_handler']);
	}
	
	//Add documentation links to modules page
	if($form_id==='system_modules' && !isset($form['confirm'])) {
		foreach (element_children($form['modules']) as $package) {
			$form['modules'][$package]['#header'][4]['colspan'] = 4;
			
			foreach(element_children($form['modules'][$package]) as $key){
				$module = &$form['modules'][$package][$key];

				// Stick it into $module for easier accessing.
				$module['links']['documentation'] = array(
					'#type' => 'link',
					'#title' => 'Write Documentation',
					'#href' => "admin/documentation/module/$key",
					'#options' => array (
						'attributes' => array(
							'class' => array(
								'module-link',
								'module-link-documentation',
							),
						),
					),
				);
			}
		}
	}
		
//	dsm($form_id);
//	dsm(print_r($form,true));
//	dsm(get_defined_vars());
}
/**
 * This function modifies the modules page to load in using a custom function, for the purpose of adding the Write Documentation links
 */
function doc_theme_registry_alter(&$theme_registry) {
	if (!empty($theme_registry['system_modules_fieldset'])) {
		$doc_theme_path = drupal_get_path('module', 'doc');
		$doc_theme_file = 'doc.admin.inc';
		$theme_registry['system_modules_fieldset']['file'] = 'doc_theme_file';
		$theme_registry['system_modules_fieldset']['theme path'] = $doc_theme_path;
		$theme_registry['system_modules_fieldset']['function'] = 'doc_theme_system_modules_fieldset';
		$theme_registry['system_modules_fieldset']['includes'][0] = $doc_theme_path.'/'.$doc_theme_file;
	}
}
/**
 * This function generates the documentation field
 */
function doc_generateFields(&$form,&$form_id) {
	global $doc_entities;

	$id = doc_convertArrayToKeys($doc_entities[$form_id]['#id'],$form);
	$entity = $doc_entities[$form_id]['#entity'];
	$fieldset = doc_isset($doc_entities[$form_id],'#fieldset');

	$doc_field = array(
		'#type' => 'fieldset',
		'#title' => 'Documentation',
		'#collapsible' => true,
		'#group' => $fieldset,
		'documentation' => array(
			'#title' => 'Create Documentation',
			'#type' => 'textarea',
			'#description' => t('Provide documentation for this @entity.',array('@entity' => $entity)),
			'#default_value' => variable_get("doc_{$entity}_{$id}"),
		),
	);
		
	$form['doc']['fieldset'] = $doc_field;
}

/**
 * This is a convenience function that replaces PHP's native isset
 */
function doc_isset($var,$index=false,$default_value='') {
	$return_value = (isset($var) ? $var : $default_value);

	if($index){
		$return_value = (isset($var[$index]) ? $var[$index] : $default_value);
	}

	return $return_value;
}
/**
 * This is a convenience function that allows for array key paths to be encoded in another array
 */
function doc_convertArrayToKeys($keys,$arrayToAccess){
	if(is_string($keys)){
		return $keys;
	} elseif(is_array($keys)){
		if(count($keys) > 1) 
			if(isset($arrayToAccess[$keys[0]])){
				return doc_convertArrayToKeys(array_slice($keys, 1), $arrayToAccess[$keys[0]]);
			} else
				return '';
		else
 //     dsm($arrayToAccess);
			return $arrayToAccess[$keys[0]];	
	}
}