Refactor the way that the rss module works so that we're not allowing

the url to dictate arbitrary static method calls.

* Each xxx_rss helper has a single feed() call which takes an id as the argument

* xxx_rss::available_feedS() only returns feeds when they're applicable (ie
  if you're viewing a tag, it won't show you an item feed).

* Feed urls are now in the module/feed_id form so that we can bind a
  feed id to a given module

* Tightened up the Rss_Controller by using url::merge and some other tricks.

* Made the slideshow module express its own feed.

9 files changed, 161 insertions, 144 deletions

diff --git a/modules/comment/helpers/comment_rss.php b/modules/comment/helpers/comment_rss.php
index c3eb7b2b..afcc275c 100644
--- a/modules/comment/helpers/comment_rss.php
+++ b/modules/comment/helpers/comment_rss.php
@@ -19,48 +19,60 @@
  */
 
 class comment_rss_Core {
-  static function available_feeds($item) {
-    return array(array("description" => t("All new comments"),
-                       "uri" => "comments"),
-                 array("description" => sprintf(t("Comments on %s"), $item->title),
-                       "uri" => "comments/{$item->id}"));
+  static function available_feeds($item, $tag) {
+    $feeds["comment/newest"] = t("All new comments");
+    if ($item) {
+      $feeds["comment/item/$item->id"] =
+        t("Comments on %title", array("title" => p::clean($item->title)));
+    }
+    return $feeds;
   }
 
-  static function comments($offset, $limit, $id) {
-    $comments = ORM::factory("comment")
-      ->where("state", "published")
-      ->orderby("created", "DESC");
-    if ($id) {
-      $comments->where("item_id", $id);
-    }
+  static function feed($feed_id, $offset, $limit, $id) {
+    switch ($feed_id) {
+    case "newest":
+      $comments = ORM::factory("comment")
+        ->where("state", "published")
+        ->orderby("created", "DESC");
+      $all_comments = ORM::factory("comment")
+        ->where("state", "published")
+        ->orderby("created", "DESC");
+      break;
 
-    $feed->view = "comment.mrss";
-    $comments = $comments->find_all($limit, $offset);
-    $feed->children = array();
-    foreach ($comments as $comment) {
-      $item = $comment->item();
-      $feed->children[] = new ArrayObject(
-        array("pub_date" => date("D, d M Y H:i:s T", $comment->created),
-              "text" => $comment->text,
-              "thumb_url" => $item->thumb_url(),
-              "thumb_height" => $item->thumb_height,
-              "thumb_width" => $item->thumb_width,
-              "item_uri" => url::abs_site("{$item->type}s/$item->id"),
-              "title" => $item->title,
-              "author" => $comment->author_name()),
-        ArrayObject::ARRAY_AS_PROPS);
+    case "item":
+      $comments = ORM::factory("comment")
+        ->where("state", "published")
+        ->orderby("created", "DESC")
+        ->where("item_id", $id);
+      $all_comments = ORM::factory("comment")
+        ->where("state", "published")
+        ->where("item_id", $id);
     }
 
-    $all_comments = ORM::factory("comment")->where("state", "published");
-    if ($id) {
-      $all_comments->where("item_id", $id);
-    }
+    if (!empty($comments)) {
+      $feed->view = "comment.mrss";
+      $comments = $comments->find_all($limit, $offset);
+      $feed->children = array();
+      foreach ($comments as $comment) {
+        $item = $comment->item();
+        $feed->children[] = new ArrayObject(
+          array("pub_date" => date("D, d M Y H:i:s T", $comment->created),
+                "text" => $comment->text,
+                "thumb_url" => $item->thumb_url(),
+                "thumb_height" => $item->thumb_height,
+                "thumb_width" => $item->thumb_width,
+                "item_uri" => url::abs_site("{$item->type}s/$item->id"),
+                "title" => $item->title,
+                "author" => $comment->author_name()),
+          ArrayObject::ARRAY_AS_PROPS);
+      }
 
-    $feed->max_pages = ceil($all_comments->find_all()->count() / $limit);
-    $feed->title = htmlspecialchars(t("Recent Comments"));
-    $feed->uri = url::abs_site("albums/" . (empty($id) ? "1" : $id));
-    $feed->description = t("Recent Comments");
+      $feed->max_pages = ceil($all_comments->find_all()->count() / $limit);
+      $feed->title = htmlspecialchars(t("Recent Comments"));
+      $feed->uri = url::abs_site("albums/" . (empty($id) ? "1" : $id));
+      $feed->description = t("Recent Comments");
 
-    return $feed;
+      return $feed;
+    }
   }
 }
\ No newline at end of file
diff --git a/modules/gallery/helpers/gallery_rss.php b/modules/gallery/helpers/gallery_rss.php
index 413d12a4..6e966bdb 100644
--- a/modules/gallery/helpers/gallery_rss.php
+++ b/modules/gallery/helpers/gallery_rss.php
@@ -19,45 +19,44 @@
  */
 
 class gallery_rss_Core {
-  static function available_feeds($item) {
-    return array(array("description" => t("New photos or movies"),
-                       "uri" => "updates"),
-                 array("description" => t("Album feed"),
-                       "uri" => "albums"));
+  static function available_feeds($item, $tag) {
+    $feeds["gallery/latest"] = t("Latest photos and movies");
+    return $feeds;
   }
 
-  static function updates($offset, $limit) {
-    $feed->children = ORM::factory("item")
-      ->viewable()
-      ->where("type !=", "album")
-      ->orderby("created", "DESC")
-      ->find_all($limit, $offset);
-
-    $all_children = ORM::factory("item")
-      ->viewable()
-      ->where("type !=", "album")
-      ->orderby("created", "DESC");
-
-    $feed->max_pages = ceil($all_children->find_all()->count() / $limit);
-    $feed->title = t("Recent Updates");
-    $feed->link = url::abs_site("albums/1");
-    $feed->description = t("Recent Updates");
-
-    return $feed;
-  }
-
-  static function albums($offset, $limit, $id) {
-    $item = ORM::factory("item", $id);
-    access::required("view", $item);
-
-    $feed->children = $item
-      ->viewable()
-      ->descendants($limit, $offset, "photo");
-    $feed->max_pages = ceil($item->viewable()->descendants_count("photo") / $limit);
-    $feed->title = $item->title;
-    $feed->link = url::abs_site("albums/{$item->id}");
-    $feed->description = $item->description;
-
-    return $feed;
+  static function feed($feed_id, $offset, $limit, $id) {
+    switch ($feed_id) {
+    case "latest":
+      $feed->children = ORM::factory("item")
+        ->viewable()
+        ->where("type !=", "album")
+        ->orderby("created", "DESC")
+        ->find_all($limit, $offset);
+
+      $all_children = ORM::factory("item")
+        ->viewable()
+        ->where("type !=", "album")
+        ->orderby("created", "DESC");
+
+      $feed->max_pages = ceil($all_children->find_all()->count() / $limit);
+      $feed->title = t("Recent Updates");
+      $feed->link = url::abs_site("albums/1");
+      $feed->description = t("Recent Updates");
+      return $feed;
+
+    case "album":
+      $item = ORM::factory("item", $id);
+      access::required("view", $item);
+
+      $feed->children = $item
+        ->viewable()
+        ->descendants($limit, $offset, "photo");
+      $feed->max_pages = ceil($item->viewable()->descendants_count("photo") / $limit);
+      $feed->title = $item->title;
+      $feed->link = url::abs_site("albums/{$item->id}");
+      $feed->description = $item->description;
+
+      return $feed;
+    }
   }
 }
diff --git a/modules/gallery/helpers/gallery_theme.php b/modules/gallery/helpers/gallery_theme.php
index 290434ed..f955e8f7 100644
--- a/modules/gallery/helpers/gallery_theme.php
+++ b/modules/gallery/helpers/gallery_theme.php
@@ -42,10 +42,6 @@ class gallery_theme_Core {
       $buf .= html::script("modules/gallery/js/fullsize.js");
     }
 
-    if ($theme->item()) {
-      $buf .= rss::feed_link("albums/{$theme->item()->id}");
-    }
-
     if ($session->get("l10n_mode", false)) {
       $buf .= "<link rel=\"stylesheet\" type=\"text/css\" href=\"" .
         url::file("modules/gallery/css/l10n_client.css") . "\" />";
diff --git a/modules/rss/controllers/rss.php b/modules/rss/controllers/rss.php
index 29300d58..e9dd9fff 100644
--- a/modules/rss/controllers/rss.php
+++ b/modules/rss/controllers/rss.php
@@ -20,37 +20,43 @@
 class Rss_Controller extends Controller {
   public static $page_size = 20;
 
-  public function feed($method, $id=null) {
+  public function feed($module_id, $feed_id, $id=null) {
     $page = $this->input->get("page", 1);
-    $feed_uri = "rss/feed/$method" . (empty($id) ? "" : "/$id");
     if ($page < 1) {
-      url::redirect($feed_uri);
+      url::redirect(url::merge(array("page" => 1)));
     }
 
-    $feed = rss::feed_data($method, ($page - 1) * self::$page_size, self::$page_size, $id);
-    $max_pages = $feed->max_pages;
-    if ($max_pages && $page > $max_pages) {
-      url::redirect("$feed_uri?page={$max_pages}");
+    // Run the appropriate feed callback
+    if (module::is_active($module_id)) {
+      $class_name = "{$module_id}_rss";
+      if (method_exists($class_name, "feed")) {
+        $feed = call_user_func(
+          array($class_name, "feed"), $feed_id,
+          ($page - 1) * self::$page_size, self::$page_size, $id);
+      }
+    }
+    if (empty($feed)) {
+      Kohana::show_404();
+    }
+
+    if ($feed->max_pages && $page > $feed->max_pages) {
+      url::redirect(url::merge(array("page" => $feed->max_pages)));
     }
 
     $view = new View(empty($feed->view) ? "feed.mrss" : $feed->view);
     unset($feed->view);
 
-    $feed->uri = url::abs_site($feed_uri);
     $view->feed = $feed;
+    $view->pub_date = date("D, d M Y H:i:s T");
 
+    $feed->uri = url::abs_site(Router::$current_uri);
     if ($page > 1) {
-      $previous_page = $page - 1;
-      $feed->previous_page_uri = url::site("$feed_uri?page={$previous_page}");
+      $feed->previous_page_uri = url::abs_site(url::merge(array("page" => $page - 1)));
     }
-
-    if ($page < $max_pages) {
-      $next_page = $page + 1;
-      $feed->next_page_uri = url::site("$feed_uri?page={$next_page}");
+    if ($page < $feed->max_pages) {
+      $feed->next_page_uri = url::abs_site(url::merge(array("page" => $page + 1)));
     }
 
-    $view->pub_date = date("D, d M Y H:i:s T");
-
     rest::http_content_type(rest::RSS);
     print $view;
   }
diff --git a/modules/rss/helpers/rss.php b/modules/rss/helpers/rss.php
index 8a7d0c97..81ff175f 100644
--- a/modules/rss/helpers/rss.php
+++ b/modules/rss/helpers/rss.php
@@ -19,34 +19,18 @@
  */
 
 class rss_Core {
-  static function feed_link($uri) {
-    $url = url::site("rss/feed/$uri");
-    return "<link rel=\"alternate\" type=\"" . rest::RSS . "\" href=\"$url\" />";
-  }
-
   /**
-   * Get all available rss feeds
+   * Convert a rss feed id into a rss feed url.
    */
-  static function available_feeds($item) {
-    $feeds = array();
-    foreach (module::active() as $module) {
-      $class_name = "{$module->name}_rss";
-      if (method_exists($class_name, "available_feeds")) {
-        foreach (call_user_func(array($class_name, "available_feeds"), $item) as $feed) {
-          $feeds[$feed["description"]] = url::site("rss/feed/{$feed['uri']}");
-        }
-      }
-    }
-
-    return $feeds;
+  static function url($uri) {
+    return url::site("rss/feed/$uri");
   }
 
-  static function feed_data($method, $offset, $limit, $id) {
-    foreach (module::active() as $module) {
-      $class_name = "{$module->name}_rss";
-      if (method_exists($class_name, $feed)) {
-        return call_user_func(array($class_name, $feed), $offset, $limit, $id);
-      }
-    }
+  /**
+   * Return a <link> element for a given rss feed id.
+   */
+  static function feed_link($uri) {
+    $url = url::site("rss/feed/$uri");
+    return "<link rel=\"alternate\" type=\"" . rest::RSS . "\" href=\"$url\" />";
   }
 }
\ No newline at end of file
diff --git a/modules/rss/helpers/rss_theme.php b/modules/rss/helpers/rss_theme.php
index 52d988bf..3d1b9a29 100644
--- a/modules/rss/helpers/rss_theme.php
+++ b/modules/rss/helpers/rss_theme.php
@@ -19,17 +19,22 @@
  */
 class rss_theme_Core {
   static function sidebar_blocks($theme) {
-    // @todo this needs to be data driven
-    if (!$theme->item()) {
-      return;
-    }
-
     $block = new Block();
     $block->css_id = "gRss";
     $block->title = t("Available RSS Feeds");
     $block->content = new View("rss_block.html");
-    $block->content->feeds = rss::available_feeds($theme->item());
+    $block->content->feeds = array();
+    foreach (module::active() as $module) {
+      $class_name = "{$module->name}_rss";
+      if (method_exists($class_name, "available_feeds")) {
+        $block->content->feeds = array_merge(
+          $block->content->feeds,
+          call_user_func(array($class_name, "available_feeds"), $theme->item(), $theme->tag()));
+      }
+    }
 
-    return $block;
+    if ($block->content->feeds) {
+      return $block;
+    }
   }
 }
diff --git a/modules/rss/views/rss_block.html.php b/modules/rss/views/rss_block.html.php
index f964329c..39921d7d 100644
--- a/modules/rss/views/rss_block.html.php
+++ b/modules/rss/views/rss_block.html.php
@@ -1,9 +1,9 @@
 <?php defined("SYSPATH") or die("No direct script access.") ?>
 <ul id="gFeeds">
-<? foreach($feeds as $title => $url): ?>
+<? foreach($feeds as $url => $title): ?>
   <li style="clear: both;">
     <span class="ui-icon-left">
-    <a href="<?= $url ?>">
+    <a href="<?= rss::url($url) ?>">
       <span class="ui-icon ui-icon-signal-diag"></span>
       <?= $title ?>
     </a>
diff --git a/modules/slideshow/helpers/slideshow_theme.php b/modules/slideshow/helpers/slideshow_theme.php
index 125d175c..69acb113 100644
--- a/modules/slideshow/helpers/slideshow_theme.php
+++ b/modules/slideshow/helpers/slideshow_theme.php
@@ -20,7 +20,17 @@
 class slideshow_theme_Core {
   static function head($theme) {
     $proto = (empty($_SERVER["HTTPS"]) || $_SERVER["HTTPS"] === "off") ? "http" : "https";
-    return "<script src=\"$proto://lite.piclens.com/current/piclens_optimized.js\"" .
+
+    if (module::is_active("rss")) {
+      if ($item = $theme->item()) {
+        $buf = rss::feed_link("gallery/album/{$item->id}");
+      } else if ($tag = $theme->tag()) {
+        $buf = rss::feed_link("tag/{$tag->id}");
+      }
+    }
+
+    $buf .= "<script src=\"$proto://lite.piclens.com/current/piclens_optimized.js\"" .
       "type=\"text/javascript\"></script>";
+    return $buf;
   }
 }
diff --git a/modules/tag/helpers/tag_rss.php b/modules/tag/helpers/tag_rss.php
index dbef3914..f94508cf 100644
--- a/modules/tag/helpers/tag_rss.php
+++ b/modules/tag/helpers/tag_rss.php
@@ -19,23 +19,28 @@
  */
 
 class tag_rss_Core {
-  static function available_feeds($item) {
-    return array(array("description" => t("Tag Album feed"),
-                       "uri" => "tags"));
-  }
-
-  static function tags($offset, $limit, $id) {
-    $tag = ORM::factory("tag", $id);
-    if (!$tag->loaded) {
-      return Kohana::show_404();
+  static function available_feeds($item, $tag) {
+    if ($tag) {
+      $feeds["tag/tag/{$tag->id}"] =
+        t("Tag feed for %tag_name", array("tag_name" => p::clean($tag->name)));
+      return $feeds;
     }
+    return array();
+  }
 
-    $feed->children = $tag->items($limit, $offset, "photo");
-    $feed->max_pages = ceil($tag->count / $limit);
-    $feed->title = $tag->name;
-    $feed->link = url::abs_site("tags/{$tag->id}");
-    $feed->description = t("Photos related to %tag_name", array("tag_name" => $tag->name));
+  static function feed($feed_id, $offset, $limit, $id) {
+    if ($feed_id == "tag") {
+      $tag = ORM::factory("tag", $id);
+      if (!$tag->loaded) {
+        Kohana::show_404();
+      }
+      $feed->children = $tag->items($limit, $offset, "photo");
+      $feed->max_pages = ceil($tag->count / $limit);
+      $feed->title = $tag->name;
+      $feed->link = url::abs_site("tags/{$tag->id}");
+      $feed->description = t("Photos related to %tag_name", array("tag_name" => $tag->name));
 
-    return $feed;
+      return $feed;
+    }
   }
 }