Alter hook calls and update documentation to reflect it.

includes/islandora.ingest.inc

@@ -95,7 +95,7 @@ function islandora_ingest_new_object_prepare($namespace = NULL, $label = NULL, $
  */
 function islandora_ingest_add_object(&$object) {
   $object->repository->ingestObject($object);
-  module_invoke_all('islandora_ingest_post_ingest', $object);
+  islandora_invoke(ISLANDORA_POST_INGEST_HOOK, $object);
   return $object;
 }
 

islandora.api.php

@@ -6,116 +6,128 @@
  */
 
 /**
- * remove a datastream from a repository object
- * @param object $fedora_object
- *  tuque FedoraObject
- * @param string $datastream_id
- */
-function hook_islandora_purge_datastream($fedora_object, $datastream_id) {}
-
-/**
+ * Allows modules to add to a repository objects view/edit(/misc) process.
  *
- * @param type $object
- *   tuque FedoraObject
- */
-function hook_islandora_purge_object($islandora_object) {}
-
-/**
- * allows modules to add to a repository objects display.  If you implement this
- * hook you should also register your module for view with the get types hook.
+ * If you implement this hook you must also register your module for view
+ * with the hook_islandora_get_types().
  *
- * islandora gets all displays back in an array and iterates over them.  the order
- * they are displayed is based on the order of the key of the array that each
- * module returns.
+ * Islandora gets all displays back in an array.  The order they are displayed
+ * is based on the order of the key of the array that each module returns.
  *
- * your module may also want to register a varible that says whether or not it
- * should be part of the default display. Modules can also add secondary tabs as
- * a way to add there output to an islandora display.  the basic image module has
- * samples of both (the secondary tabs examples are commented out)
+ * "HOOK_NAME" reflects those provided by the islandora_get_types() function,
+ * and these functions should be called via islandora_invoke().  There are a
+ * number of these hooks defined at the top of islandora.module, including:
+ * - ISLANDORA_VIEW_HOOK: Invoked in islandora_view_object(); returns an array
+ *     containing string values, and whose keys will be used for sorting.
+ *     Takes four parameters:
+ *   - fedora_object: A Tuque FedoraObject being operated on.
+ *   - user: The user accessing the object.
+ *   - page_number: The page in the content.
+ *   - page_size: The size o the page.
+ * - ISLANDORA_EDIT_HOOK: Invoked in islandora_edit_object(); returns an array
+ *     containing string values, whose keys will be used for sorting.
+ *     Takes one parameter:
+ *   - fedora_object: A Tuque FedoraObject being operated on.
+ * - ISLANDORA_POST_INGEST_HOOK: Invoked in islandora_ingest_add_object(); no
+ *     return.  Probably want to use this to add additional datastreams, or
+ *     or perhap remove some.  Takes one parameter:
+ *   - The object in question.
+ * - ISLANDORA_PRE_PURGE_OBJECT_HOOK: Invoked in islandora_object_purge(); can
+ *     return an associative array of with the key "delete" mapped to TRUE,
+ *     which will cause the object to be marked "deleted" instead of actually
+ *     purging the object. (This should be verirfied?)
  *
  * @param type $islandora_object
- *   tuque FedoraObject
- */
-function hook_islandora_view_object($islandora_object) {}
-
-/**
- * returns an array listing object types provided by sub modules
- *  Ex.  array($types['islandora:collectionCModel'][ISLANDORA_VIEW_HOOK] = variable_get('islandora_basic_collection_use_for_default_tab', TRUE);
- * $types['islandora:collectionCModel'][ISLANDORA_EDIT_HOOK] = FALSE;
+ *   A Tuque FedoraObject
+ * @param ...
+ *   A variable list of arguments, as required by the in question hook.
  *
  * @return array
+ *   An array to merge in.
  */
-function hook_islandora_get_types() {}
+function hook_HOOK_NAME($islandora_object) {}
 
 /**
- * allows modules to define an object edit page by cmodel
- *
- * your module should return true for ISLANDORA_EDIT_HOOK in its get_types function
- *
- * islandora provides a default implementation that should work for most use cases
- * @param string $islandora_object
- * @return string
- *
+ * Alter an object before further processing in islandora_invoke().
  */
-function hook_islandora_edit_object($islandora_object) {}
+function hook_HOOK_NAME_alter($fedora_object) {}
 
 /**
- * allows modules to alter the fedora object before it is pass through the edit
- * hooks
- * @param type $islandora_object
- *   a tugue FedoraObject
+ * Allow output of hooks passing through islandora_invoke() to be altered.
+ * @param type $arr
+ *   an arr of rendered views
  */
-function hook_islandora_edit_object_alter($islandora_object) {}
+function hook_HOOK_NAME_output_alter($arr) {}
 
 
 /**
- * creates and populates a php Fedora object.
+ * Get an array of object types provided by other modules.
+ *
+ * @return array
+ *   An associative array mapping cmodel PIDs to module names to hooks to
+ *   booleans indicating that the given module's implementation of the hook
+ *   should be invoked.
  */
-function hook_islandora_preingest_alter() {}
+function hook_islandora_get_types() {
+  $types = array(
+    'my:coolCModel' => array(
+      'my_cool_module' => array(
+        ISLANDORA_VIEW_HOOK => TRUE,
+      ),
+    ),
+  );
+  return $types;
+}
 
 /**
- * modules can implement this hook to add or remove datastreams after an
- * object has been ingested.
+ * Allows modules to define an object edit page by cmodel.
  *
- * Each module should check for the newly ingested repository objects content
- * model to make sure it is a type of object they want to act on.
+ * Your module must return TRUE for ISLANDORA_EDIT_HOOK in its
+ * implementation of hook_islandora_get_types().
  *
- * @param type $islandora_object
- *   tugue FeodoraObject
+ * Islandora provides a default implementation that should work for most use
+ * cases.
+ *
+ * @param object $islandora_object
+ *   A Tuque FedoraObject to be edited.
+ * @return array
+ *   An array of strings containing markup, which will be imploded together.
  */
-function hook_islandora_postingest($islandora_object) {}
+function hook_islandora_edit_object($islandora_object) {}
 
 /**
- * Register potential ingest routes. Implementations should return an array containing possible routes.
- * Ex. array(
- *       array('name' => t('Ingest Route Name'), 'url' => 'ingest_route/url', 'weight' => 0),
- *     );
+ * Register potential ingest routes.
+ *
+ * Implementations should return an array containing possible routes.
  */
-function hook_islandora_ingest_registry($collection_object) {}
+function hook_islandora_ingest_registry($collection_object) {
+  $reg = array(
+    array(
+      'name' => t('Ingest Route Name'),
+      'url' => 'ingest_route/url',
+      'weight' => 0,
+    ),
+  );
+  return $reg
+}
 
 /**
  * Register a datastream edit route/form.
+ *
  * @param $islandora_object
  * @param $ds_id
  */
 function hook_islandora_edit_datastream_registry($islandora_object, $ds_id) {}
 
 /**
- * alter an object before it gets used further down the stack
+ * Alter an object before it gets used further down the stack.
  * @param type $object
- *   a tuque FedoraObject
+ *   A Tuque FedoraObject
  */
 function hook_islandora_object_alter($fedora_object) {}
 
 /**
- * insert or remove rendered elements by implementing this function
- * in your module
- * @param type $arr
- *   an arr of rendered views
- */
-function hook_islandora_display_alter($arr) {}
-
-/**
+ * Allow modification of an object before ingesting.
  *
  * @param type $islandora_object
  *   a tuque FedoraObject
@@ -123,3 +135,32 @@ function hook_islandora_display_alter($arr) {}
  * @param string $collection_pid
  */
 function hook_islandora_ingest_pre_ingest($islandora_object, $content_models, $collection_pid) {}
+
+/**
+ * Allow modules to setup for the purge of a datastream.
+ *
+ * @param object $datastream
+ *   A Tuque FedoraDatastream object.
+ */
+function hook_islandora_pre_purge_datastream($datastream) {}
+
+/**
+ * Allow modules to react after a datastream is purged.
+ *
+ * @param object $object
+ *   A Tuque FedoraObject.
+ * @param string $dsid
+ *   A id of the former datastream.
+ */
+function hook_islandora_post_purge_datastream($object, $dsid) {}
+
+/**
+ * Allow modules to react post-purge.
+ *
+ * @param string $object_id
+ *   The former object's PID.
+ * @param array $content_models
+ *   An array containing the models to which the former object.
+ */
+function hook_islandora_post_purge_object($object_id, $content_models) {}
+

islandora.module

@@ -31,9 +31,11 @@ define('FEDORA_PURGE', 'delete fedora objects and datastreams');
 define('FEDORA_MODIFY_STATE', 'modify fedora state');
 define('FEDORA_MANAGE', 'manage fedora items');
 
-// hooks
+// Hooks
 define('ISLANDORA_VIEW_HOOK', 'islandora_view_object');
 define('ISLANDORA_EDIT_HOOK', 'islandora_edit_object');
+define('ISLANDORA_POST_INGEST_HOOK', 'islandora_ingest_post_ingest');
+define('ISLANDORA_PRE_PURGE_OBJECT_HOOK', 'islandora_pre_purge_object');
 
 /**
  * Implements hook_menu().
@@ -250,11 +252,40 @@ function islandora_access_callback($object = NULL, $perm = NULL) {
 }
 
 /**
- * returns an array listing object types provided by sub modules
+ * Returns an array listing object types.
+ *
+ * @param string $model
+ *   A string representing a short content model URI, to only get the relevant
+ *   elements.
+ *
  * @return array
+ *   An associative array mapping cmodel pids to modules to a boolean
+ *   indicating if the hook on the given module should be called.
+ *
+ * @todo
+ *   Rename this function and the hook, as it now has a wider usage.
  */
-function islandora_get_types() {
-  return module_invoke_all('islandora_get_types');
+function islandora_get_types($model = NULL) {
+  $types = &drupal_static(__FUNCTION__);
+
+  if ($types === NULL) {
+    $types = module_invoke_all('islandora_get_types');
+    drupal_alter('islandora_get_types', $types);
+
+    // TODO: Add in the defaults, where there's no view or edit?
+  }
+
+  if ($model !== NULL) {
+    if (isset($types[$model])) {
+      return $types[$model];
+    }
+    else {
+      return array();
+    }
+  }
+  else {
+    return $types;
+  }
 }
 
 function islandora_init() {
@@ -287,13 +318,64 @@ function islandora_edit_object($object) {
   if (!$object) {
     return drupal_not_found();
   }
-  drupal_alter('islandora_edit_object', $object);
-  $arr = module_invoke_all('islandora_edit_object', $object);
-  $output = "";
-  foreach ($arr as $key => $value) {
-    $output .= $value; //if we have multiple modules handle one cmodel we need to iterate over multiple
+
+  $output = islandora_invoke(ISLANDORA_EDIT_HOOK, $object);
+
+  // Add in the default, if we did not get any results.
+  if (empty($output)) {
+    $output = islandora_islandora_edit_object($object);
   }
+
   //we could do another module invoke all here to build the edit tab with a default implemented in this module?
+  return implode('', $output);
+}
+
+/**
+ * Invoke a hook registered via islandora_get_types().
+ *
+ * @param string $hook
+ *   The hook to invoke.
+ * @param object $object
+ *   The object to be affected by the hook.
+ * @param ...
+ *   An optional variable list of arguments.
+ *
+ * @return array
+ *   The array of results.
+ */
+function islandora_invoke($hook, $object) {
+  // Allow altering of the object, before processing.
+  drupal_alter($hook, $object);
+
+  // Accumulate the output
+  $output = array();
+
+  // Get the models...
+  $supported_models = islandora_get_types();
+
+  // Filter them down to only the ones explicitly supported.
+  $models = array_intersect(array_keys($supported_models), $object->models);
+
+  // And actually call out to accumulate the output for each model.
+  foreach($models as $model) {
+    foreach ($supported_models[$model] as $module => $hooks) {
+      if (isset($hooks[$hook]) && $hooks[$hook]) {
+        $args = func_get_args();
+
+        // Add the module into the list of args, and call module_invoke.
+        array_unshift($args, $module);
+        $return = call_user_func_array('module_invoke', $args);
+        if (is_array($return)) {
+          $output = array_merge_recursive($output, $return);
+        } 
+      }
+    }
+  }
+
+  arsort($output);
+
+  drupal_alter($hook . '_output', $output);  
+
   return $output;
 }
 
@@ -314,20 +396,16 @@ function islandora_edit_properties($object_id) {
 }
 
 /**
- * builds a default page for the edit tab
+ * Builds a default page for the edit tab.
  *
  * @param object $fedora_object
  *   A tuque Fedora Object
  */
 function islandora_islandora_edit_object($fedora_object) {
-  $supported_models = islandora_get_types();
-  $output = "";
-  foreach ($fedora_object->models as $model) {
-    if (isset($supported_models[$model][ISLANDORA_EDIT_HOOK]) && $supported_models[$model][ISLANDORA_EDIT_HOOK] == TRUE) {//another module is handling the view
-      return;
-    }
-  }
-  $output = theme('islandora_default_edit', array('islandora_object' => $fedora_object));
+  $output = theme('islandora_default_edit', array(
+    'islandora_object' => $fedora_object,
+  ));
+
   return array('Default Edit output' => $output);
 }
 
@@ -357,20 +435,13 @@ function islandora_view_object($fedora_object = NULL) {
   $page_number = (empty($_GET['page'])) ? '1' : $_GET['page'];
   $page_size = (empty($_GET['pagesize'])) ? '10' : $_GET['pagesize'];
 
-  drupal_alter('islandora_object', $fedora_object); //modify object if required before it is passed along
-  $arr = module_invoke_all('islandora_view_object', $fedora_object, $user, $page_number, $page_size); //allow submodules to decide how to handle content base on object type
-  if (empty($arr)) {
-    //TODO: make sure we iterate over the array as they will be more then one cmodel per object
-    drupal_set_message(t('there was an error loading the view for islandora object %s', array('%s' => $object_id)), 'error');
-    return "";
-  }
-  arsort($arr);
-  drupal_alter('islandora_display', $arr);
-  $output = "";
-  foreach ($arr as $key => $value) {
-    $output .= $value; //if we have multiple modules handle one cmodel we need to iterate over multiple
+  $output = islandora_invoke(ISLANDORA_VIEW_HOOK, $fedora_object, $user, $page_number, $page_size);
+
+  if (empty($output)) {
+    $output = islandora_islandora_view_object($fedora_object);
   }
-  return $output;
+
+  return implode('', $output);
 }
 
 /**
@@ -381,13 +452,6 @@ function islandora_view_object($fedora_object = NULL) {
  * @return string
  */
 function islandora_islandora_view_object($object) {
-  $supported_models = islandora_get_types();
-  $output = "";
-  foreach ($object->models as $model) {
-    if (isset($supported_models[$model][ISLANDORA_VIEW_HOOK]) && (boolean) $supported_models[$model][ISLANDORA_VIEW_HOOK] === TRUE) {//another module is handling the view
-      return;
-    }
-  }
   $output = theme('islandora_default', array('islandora_object' => $object));
   return array('Default Output' => $output);
 }
@@ -459,7 +523,7 @@ function islandora_permission() {
  */
 function islandora_object_load($object_id) {
   module_load_include('inc', 'islandora', 'includes/tuque');
-  static $islandora_tuque = NULL;
+  $islandora_tuque = &drupal_static(__FUNCTION__);
 
   if (!$islandora_tuque) {
     $islandora_tuque = new IslandoraTuque();
@@ -471,6 +535,8 @@ function islandora_object_load($object_id) {
     } catch (Exception $e) {
       return NULL;
     }
+
+    drupal_alter('islandora_object', $fedora_object);
     return $fedora_object;
   }
   else {
@@ -500,7 +566,7 @@ function islandora_object_purge($object_id) {
     return;
   }
   $content_models = $object->models;
-  $arr = module_invoke_all('islandora_pre_purge_object', $object); // notify modules of pending deletion
+  $arr = islandora_invoke(ISLANDORA_PRE_PURGE_OBJECT_HOOK, $object); // notify modules of pending deletion
   if (isset($arr['delete']) && $arr['delete']) {
     try {
       $object->delete();
@@ -517,6 +583,7 @@ function islandora_object_purge($object_id) {
       return "";
     }
   }
+
   module_invoke_all('islandora_post_purge_object', $object_id, $content_models);  // notify modules post deletion
 }