fixes #2243

app/assets/javascripts/default/favorites.js

@@ -0,0 +1,59 @@
+(function() {
+  Danbooru.Favorite = {};
+
+  Danbooru.Favorite.initialize_all = function() {
+    if ($("#c-posts").length) {
+      this.hide_or_show_add_to_favorites_link();
+    }
+  }
+
+  Danbooru.Favorite.hide_or_show_add_to_favorites_link = function() {
+    var favorites = Danbooru.meta("favorites");
+    var current_user_id = Danbooru.meta("current-user-id");
+    if (current_user_id == "") {
+      $("#add-to-favorites").hide();
+      $("#remove-from-favorites").hide();
+      return;
+    }
+    var regexp = new RegExp("\\bfav:" + current_user_id + "\\b");
+    if ((favorites != undefined) && (favorites.match(regexp))) {
+      $("#add-to-favorites").hide();
+    } else {
+      $("#remove-from-favorites").hide();
+    }
+  }
+
+  Danbooru.Favorite.create = function(post_id) {
+    Danbooru.Post.notice_update("inc");
+
+    $.ajax({
+      type: "POST",
+      url: "/favorites",
+      data: {
+        post_id: post_id
+      },
+      complete: function() {
+        Danbooru.Post.notice_update("dec");
+      },
+      error: function(data, status, xhr) {
+        Danbooru.notice("Error: " + data.reason);
+      }
+    });
+  }
+
+  Danbooru.Favorite.destroy = function(post_id) {
+    Danbooru.Post.notice_update("inc");
+
+    $.ajax({
+      type: "DELETE",
+      url: "/favorites/" + post_id,
+      complete: function() {
+        Danbooru.Post.notice_update("dec");
+      }
+    });
+  }
+})();
+
+$(document).ready(function() {
+  Danbooru.Favorite.initialize_all();
+});