Reshape the rest code to be more consistent with regards to

relationships.  Now when you view a resource, it has 4 top level
elements:

url: the url of this resource
resource: array of key value pairs describing the resource
members: array of urls to members of this collection
relationships: array of array of members.

Relationships are a special type of collection that links two
different resources together.  To remove a relationship, just
DELETE its url.  To create a relationship, POST to its
collection.

Individual modules can add their own relationships to any
resource via a callback mechanism.

Example:
  Array(
    [url] => http://g3.com/rest/item/1
    [resource] => Array (
      [id] => 1
      [album_cover_item_id] => 4
      [captured] =>
      [created] => 1264056417
      [description] =>
      [height] =>
      ...
    )
    [members] => Array(
      [0] => http://g3.com/rest/item/2
      [1] => http://g3.com/rest/item/3
      [2] => http://g3.com/rest/item/4
      [3] => http://g3.com/rest/item/5
      ...
    )
    [relationships] => Array(
      [tags] => Array (
      [0] => http://g3.com/rest/tag_item/2,1
      [1] => http://g3.com/rest/tag_item/23,1
      )
    )
  )

8 files changed, 148 insertions, 55 deletions

diff --git a/modules/gallery/helpers/gallery_rest.php b/modules/gallery/helpers/item_rest.php
index c5838ea5..edc44c45 100644
--- a/modules/gallery/helpers/gallery_rest.php
+++ b/modules/gallery/helpers/item_rest.php
@@ -17,7 +17,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
  */
-class gallery_rest_Core {
+class item_rest_Core {
   /**
    * For items that are collections, you can specify the following additional query parameters to
    * query the collection.  You can specify them in any combination.
@@ -72,10 +72,14 @@ class gallery_rest_Core {
 
     $members = array();
     foreach ($orm->find_all() as $child) {
-      $members[] = rest::url("gallery", $child);
+      $members[] = rest::url("item", $child);
     }
 
-    return array("resource" => $item->as_array(), "members" => $members);
+    return array(
+      "url" => $request->url,
+      "resource" => $item->as_array(),
+      "members" => $members,
+      "relationships" => rest::relationships("item", $item));
   }
 
   static function put($request) {
@@ -94,9 +98,9 @@ class gallery_rest_Core {
         $item->$key = $request->params->$key;
       }
     }
-    $item->save();
-
-    return array("url" => rest::url("gallery", $item));
+    if ($item->changed) {
+      $item->save();
+    }
   }
 
   static function post($request) {
@@ -131,8 +135,6 @@ class gallery_rest_Core {
     default:
       throw new Rest_Exception("Invalid type: $params->type", 400);
     }
-
-    return array("url" => rest::url("gallery", $item));
   }
 
   static function delete($request) {
@@ -142,11 +144,15 @@ class gallery_rest_Core {
     $item->delete();
   }
 
-  static function resolve($path) {
-    return url::get_item_from_uri($path);
+  static function resolve($id) {
+    $item = ORM::factory("item")->where("id", "=", $id)->find();
+    if (!access::can("view", $item)) {
+      throw new Kohana_404_Exception();
+    }
+    return $item;
   }
 
   static function url($item) {
-    return url::abs_site("rest/gallery/" . $item->relative_url());
+    return url::abs_site("rest/item/{$item->id}");
   }
 }
diff --git a/modules/rest/controllers/rest.php b/modules/rest/controllers/rest.php
index 9f0bc5b3..ba996b84 100644
--- a/modules/rest/controllers/rest.php
+++ b/modules/rest/controllers/rest.php
@@ -56,7 +56,7 @@ class Rest_Controller extends Controller {
     $handler_method = $request->method;
 
     if (!method_exists($handler_class, $handler_method)) {
-      throw new Rest_Exception("Forbidden", 403);
+      throw new Rest_Exception("Bad Request", 400);
     }
 
     try {
diff --git a/modules/rest/helpers/rest.php b/modules/rest/helpers/rest.php
index 85987ca1..fe704a9e 100644
--- a/modules/rest/helpers/rest.php
+++ b/modules/rest/helpers/rest.php
@@ -22,8 +22,16 @@ class rest_Core {
     Session::abort_save();
 
     if ($data) {
-      header("Content-type: application/json");
-      print json_encode($data);
+      if (Input::instance()->get("output_type") == "html") {
+        header("Content-type: text/html");
+        $html = preg_replace(
+          "#(^|[\n ])([\w]+?://[\w]+[^ \"\n\r\t<]*)#ise", "'\\1<a href=\"\\2\" >\\2</a>'",
+          print_r($data, 1));
+        print "<pre>$html</pre>";
+      } else {
+        header("Content-type: application/json");
+        print json_encode($data);
+      }
     }
   }
 
@@ -64,7 +72,10 @@ class rest_Core {
 
   /**
    * Convert a REST url into an object.
-   * Eg: "http://example.com/gallery3/index.php/rest/gallery/Family/Wedding" -> Item_Model
+   * Eg:
+   *   http://example.com/gallery3/index.php/rest/item/35          -> Item_Model
+   *   http://example.com/gallery3/index.php/rest/tag/16           -> Tag_Model
+   *   http://example.com/gallery3/index.php/rest/tagged_item/1,16 -> [Tag_Model, Item_Model]
    *
    * @param string  the fully qualified REST url
    * @return mixed  the corresponding object (usually a model of some kind)
@@ -88,15 +99,38 @@ class rest_Core {
 
   /**
    * Return an absolute url used for REST resource location.
-   * @param  string  module name (eg, "gallery", "tags")
+   * @param  string  resource type (eg, "item", "tag")
    * @param  object  resource
    */
-  static function url($module, $resource) {
-    $class = "{$module}_rest";
+  static function url() {
+    $args = func_get_args();
+    $resource_type = array_shift($args);
+
+    $class = "{$resource_type}_rest";
     if (!method_exists($class, "url")) {
-      throw new Exception("@todo MISSING REST CLASS: $class");
+      throw new Rest_Exception("Bad Request", 400);
+    }
+
+    $url = call_user_func_array(array($class, "url"), $args);
+    if (Input::instance()->get("output_type") == "html") {
+      $url .= "?output_type=html";
+    }
+    return $url;
+  }
+
+  static function relationships($resource_type, $resource) {
+    $results = array();
+    foreach (module::active() as $module) {
+      foreach (glob(MODPATH . "{$module->name}/helpers/*_rest.php") as $filename) {
+        $class = str_replace(".php", "", basename($filename));
+        if (method_exists($class, "relationships")) {
+          $results = array_merge(
+            $results,
+            call_user_func(array($class, "relationships"), $resource_type, $resource));
+        }
+      }
     }
 
-    return call_user_func(array($class, "url"), $resource);
+    return $results;
   }
 }
diff --git a/modules/tag/helpers/tag.php b/modules/tag/helpers/tag.php
index c49a2d0f..9e59b527 100644
--- a/modules/tag/helpers/tag.php
+++ b/modules/tag/helpers/tag.php
@@ -91,16 +91,10 @@ class tag_Core {
    * @return array
    */
   static function item_tags($item) {
-    $tags = array();
-    foreach (db::build()
-             ->select("name")
-             ->from("tags")
-             ->join("items_tags", "tags.id", "items_tags.tag_id", "left")
-             ->where("items_tags.item_id", "=", $item->id)
-             ->execute() as $row) {
-      $tags[] = $row->name;
-    }
-    return $tags;
+    return ORM::factory("tag")
+      ->join("items_tags", "tags.id", "items_tags.tag_id", "left")
+      ->where("items_tags.item_id", "=", $item->id)
+      ->find_all();
   }
 
   static function get_add_form($item) {
diff --git a/modules/tag/helpers/tag_event.php b/modules/tag/helpers/tag_event.php
index 6ee8e708..403ccd52 100644
--- a/modules/tag/helpers/tag_event.php
+++ b/modules/tag/helpers/tag_event.php
@@ -71,9 +71,13 @@ class tag_event_Core {
                 $('form input[id=tags]').autocomplete(
                   '$url', {max: 30, multiple: true, multipleSeparator: ',', cacheLength: 1});
               });");
-    $tag_value = implode(", ", tag::item_tags($item));
+
+    $tag_names = array();
+    foreach (tag::item_tags($item) as $tag) {
+      $tag_names[] = $tag->name;
+    }
     $form->edit_item->input("tags")->label(t("Tags (comma separated)"))
-      ->value($tag_value);
+      ->value(implode(", ", $tag_names));
   }
 
   static function item_edit_form_completed($item, $form) {
@@ -95,7 +99,9 @@ class tag_event_Core {
   }
 
   static function item_index_data($item, $data) {
-    $data[] = join(" ", tag::item_tags($item));
+    foreach (tag::item_tags($item) as $tag) {
+      $data[] = $tag->name;
+    }
   }
 
   static function add_photos_form($album, $form) {
diff --git a/modules/tag/helpers/tag_item_rest.php b/modules/tag/helpers/tag_item_rest.php
new file mode 100644
index 00000000..cd9bb6fe
--- /dev/null
+++ b/modules/tag/helpers/tag_item_rest.php
@@ -0,0 +1,50 @@
+<?php defined("SYSPATH") or die("No direct script access.");
+/**
+ * Gallery - a web based photo album viewer and editor
+ * Copyright (C) 2000-2009 Bharat Mediratta
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+class tag_item_rest_Core {
+  static function get($request) {
+    list ($tag, $item) = rest::resolve($request->url);
+    return array(
+      "url" => $request->url,
+      "members" => array(
+        rest::url("tag", $tag),
+        rest::url("item", $item)));
+  }
+
+  static function delete($request) {
+    list ($tag, $item) = rest::resolve($request->url);
+    $tag->remove($item);
+    $tag->save();
+  }
+
+  static function resolve($tuple) {
+    list ($tag_id, $item_id) = split(",", $tuple);
+    $tag = ORM::factory("tag")->where("id", "=", $tag_id)->find();
+    $item = ORM::factory("item")->where("id", "=", $item_id)->find();
+    if (!$tag->loaded() || !$item->loaded() || !$tag->has($item)) {
+      throw new Kohana_404_Exception();
+    }
+
+    return array($tag, $item);
+  }
+
+  static function url($tag, $item) {
+    return url::abs_site("rest/tag_item/{$tag->id},{$item->id}");
+  }
+}
diff --git a/modules/tag/helpers/tag_rest.php b/modules/tag/helpers/tag_rest.php
index 0226c6d3..d68cb73d 100644
--- a/modules/tag/helpers/tag_rest.php
+++ b/modules/tag/helpers/tag_rest.php
@@ -20,12 +20,18 @@
 class tag_rest_Core {
   static function get($request) {
     $tag = rest::resolve($request->url);
-    $items = array();
+    $tag_items = array();
     foreach ($tag->items() as $item) {
-      $items[] = rest::url("gallery", $item);
+      if (access::can("view", $item)) {
+        $tag_items[] = rest::url("tag_item", $tag, $item);
+      }
     }
 
-    return array("resource" => $tag->as_array(), "members" => $items);
+    return array(
+      "url" => $request->url,
+      "resource" => $tag->as_array(),
+      "relationships" => array(
+        "items" => $tag_items));
   }
 
   static function post($request) {
@@ -38,37 +44,34 @@ class tag_rest_Core {
     access::required("edit", $item);
 
     tag::add($item, $tag->name);
-    return array("url" => rest::url("tag", $tag));
   }
 
   static function put($request) {
     $tag = rest::resolve($request->url);
     if (isset($request->params->name)) {
       $tag->name = $request->params->name;
+      $tag->save();
     }
-
-    $tag->save();
-    return array("url" => rest::url("tag", $tag));
   }
 
   static function delete($request) {
     $tag = rest::resolve($request->url);
+    $tag->delete();
+  }
 
-    if (empty($request->params->url)) {
-      // Delete the tag
-      $tag->delete();
-    } else {
-      // Remove an item from the tag
-      $item = rest::resolve($request->params->url);
-      access::required("edit", $item);
-      $tag->remove($item);
-      $tag->save();
-      tag::compact();
+  static function relationships($resource_type, $resource) {
+    switch ($resource_type) {
+    case "item":
+      $tags = array();
+      foreach (tag::item_tags($resource) as $tag) {
+        $tags[] = rest::url("tag_item", $tag, $resource);
+      }
+      return array("tags" => $tags);
     }
   }
 
-  static function resolve($tag_name) {
-    $tag = ORM::factory("tag")->where("name", "=", $tag_name)->find();
+  static function resolve($id) {
+    $tag = ORM::factory("tag")->where("id", "=", $id)->find();
     if (!$tag->loaded()) {
       throw new Kohana_404_Exception();
     }
@@ -77,6 +80,6 @@ class tag_rest_Core {
   }
 
   static function url($tag) {
-    return url::abs_site("rest/tag/" . rawurlencode($tag->name));
+    return url::abs_site("rest/tag/{$tag->id}");
   }
 }
diff --git a/modules/tag/helpers/tags_rest.php b/modules/tag/helpers/tags_rest.php
index 41317ecd..57461125 100644
--- a/modules/tag/helpers/tags_rest.php
+++ b/modules/tag/helpers/tags_rest.php
@@ -21,7 +21,7 @@ class tags_rest_Core {
   static function get($request) {
     $tags = array();
     foreach (ORM::factory("tag")->find_all() as $tag) {
-      $tags[$tag->name] = rest::url("tag", $tag);
+      $tags[] = rest::url("tag", $tag);
     }
     return array("members" => $tags);
   }
@@ -33,7 +33,7 @@ class tags_rest_Core {
     access::required("edit", item::root());
 
     if (empty($request->params->name)) {
-      throw new Rest_Exception("Bad Request: missing name", 400);
+      throw new Rest_Exception("Bad Request", 400);
     }
 
     $tag = ORM::factory("tag")->where("name", "=", $request->params->name)->find();