Allow karma to be undone without voting the other way

src/lib/discussion/Post.php

@@ -173,7 +173,7 @@
             }
         }
 
-        public function karma($up = true) {
+        public function karma($up = true, $cancel = false) {
             $DtW = \dtw\DtW::getInstance();
 
             if (!$DtW->user->isAuth()) {
@@ -189,17 +189,30 @@
                 throw new \Exception('You don\'t have enough reputation to down vote');
             }
 
-            // Insert or update
-            $stmt = \dtw\DtW::$db->prepare('
-                INSERT INTO forum_karma (`post_id`, `user_id`, `vote`)
-                VALUES (:post_id, :user_id, :vote)
-                ON DUPLICATE KEY UPDATE `vote` = :vote
-            ');
-            $stmt->execute(array(
-                ':post_id' => $this->id,
-                ':user_id' => $DtW->user->id,
-                ':vote' => $up ? 'up' : 'down',
-            ));
+            if (!$cancel) {
+                // Insert or update
+                $stmt = \dtw\DtW::$db->prepare('
+                    INSERT INTO forum_karma (`post_id`, `user_id`, `vote`)
+                    VALUES (:post_id, :user_id, :vote)
+                    ON DUPLICATE KEY UPDATE `vote` = :vote
+                ');
+                $stmt->execute(array(
+                    ':post_id' => $this->id,
+                    ':user_id' => $DtW->user->id,
+                    ':vote' => $up ? 'up' : 'down',
+                ));
+            } else {
+                // Remove vote
+                $stmt = \dtw\DtW::$db->prepare('
+                    DELETE FROM forum_karma
+                    WHERE `post_id` = :post_id AND `user_id` = :user_id AND `vote` = :vote
+                ');
+                $stmt->execute(array(
+                    ':post_id' => $this->id,
+                    ':user_id' => $DtW->user->id,
+                    ':vote' => $up ? 'up' : 'down',
+                ));
+            }
 
             // Get new total
             $this->updateKarma();
@@ -213,7 +226,11 @@
             }
 
             if ($stmt->rowCount() === 0) {
-                throw new \Exception('Karma had already been awarded for this post');
+                if (!$cancel) {
+                    throw new \Exception('Karma had already been awarded for this post');
+                } else {
+                    throw new \Exception('Karma has not been awarded for this post');
+                }
             }
         }
 

src/routes/discussion.php

@@ -620,7 +620,7 @@
             $thread = $app->DtW->discussions->getThread($request->thread);
             $post = $app->DtW->discussions->getPost($thread->id, $request->post);
 
-            $post->karma(isset($_GET['up']));
+            $post->karma(isset($_GET['up']), isset($_GET['cancel']));
 
             \dtw\utils\Flash::add('Karma awarded', 'success');
         } catch (Exception $e) {

src/www/css/_discussion.scss

@@ -288,7 +288,6 @@
                     &.discussion-thread-message-karma--up {
                         [data-karma=up] {
                             opacity: 0.3;
-                            cursor: default;
                         }
 
                         h3 {
@@ -299,7 +298,6 @@
                     &.discussion-thread-message-karma--down {
                         [data-karma=down] {
                             opacity: 0.3;
-                            cursor: default;
                         }
 
                         h3 {

src/www/js/_discussions.js

@@ -256,40 +256,46 @@ $(function() {
 
         if (action === 'up') {
             if (previousAction === 'up') {
-                return;
-            }
-
-            newValue++;
-            if (previousAction === 'down') {
+                $parent.removeClass('discussion-thread-message-karma--up');
+                action = 'cancel';
+                newValue--;
+            } else {
                 newValue++;
+                if (previousAction === 'down') {
+                    newValue++;
+                }
+
+                $parent.removeClass('discussion-thread-message-karma--down');
+                $parent.addClass('discussion-thread-message-karma--up');
             }
 
             $this.siblings('h3').text(newValue);
-
-            $parent.removeClass('discussion-thread-message-karma--down');
-            $parent.addClass('discussion-thread-message-karma--up');
         } else if (action === 'down') {
             if (previousAction === 'down') {
-                return;
-            }
-
-            newValue--;
-            if (previousAction === 'up') {
+                $parent.removeClass('discussion-thread-message-karma--down');
+                action = 'cancel';
+                newValue++;
+            } else {
                 newValue--;
+                if (previousAction === 'up') {
+                    newValue--;
+                }
+
+                $parent.removeClass('discussion-thread-message-karma--up');
+                $parent.addClass('discussion-thread-message-karma--down');
             }
 
             $this.siblings('h3').text(newValue);
-
-            $parent.removeClass('discussion-thread-message-karma--up');
-            $parent.addClass('discussion-thread-message-karma--down');
         } else {
             return;
         }
 
         $this.addClass('active');
 
+        var url = $(this).attr('href') + (action === 'cancel' ? '&cancel' : '');
+
         $.ajax({
-            url: $(this).attr('href'),
+            url: url,
             dataType: 'json',
             type: 'POST',
             data: {
@@ -302,9 +308,11 @@ $(function() {
                 // reset
                 $this.siblings('h3').text(currentValue);
 
-                $parent.removeClass('discussion-thread-message-karma--' + action);
-                if (previousAction) {
-                    $parent.addClass('discussion-thread-message-karma--' + previousAction);
+                if (action !== 'cancel') {
+                    $parent.removeClass('discussion-thread-message-karma--' + action);
+                    if (previousAction) {
+                        $parent.addClass('discussion-thread-message-karma--' + previousAction);
+                    }
                 }
             }
         });