Limit the number of reaction types which can be shown on a post

reaction.py

@@ -502,7 +502,7 @@ def updateReactionCollection(recentPostsCache: {},
 
 
 def htmlEmojiReactions(postJsonObject: {}, interactive: bool,
-                       actor: str) -> str:
+                       actor: str, maxReactionTypes: int) -> str:
     """html containing row of emoji reactions
     """
     if not hasObjectDict(postJsonObject):
@@ -515,7 +515,8 @@ def htmlEmojiReactions(postJsonObject: {}, interactive: bool,
     for item in postJsonObject['object']['reactions']['items']:
         emojiContent = item['content']
         if not reactions.get(emojiContent):
-            reactions[emojiContent] = 1
+            if len(reactions.items()) < maxReactionTypes:
+                reactions[emojiContent] = 1
         else:
             reactions[emojiContent] += 1
     if len(reactions.items()) == 0:

webapp_post.py

@@ -1304,6 +1304,10 @@ def individualPostAsHtml(signingPrivateKeyPem: str,
     if not postJsonObject:
         return ''
 
+    # maximum number of different emoji reactions which can
+    # be added to a post
+    maxReactionTypes = 5
+
     # benchmark
     postStartTime = time.time()
 
@@ -1882,7 +1886,9 @@ def individualPostAsHtml(signingPrivateKeyPem: str,
     if boxName != 'tlmedia':
         reactionStr = ''
         if showIcons:
-            reactionStr = htmlEmojiReactions(postJsonObject, True, personUrl)
+            reactionStr = \
+                htmlEmojiReactions(postJsonObject, True, personUrl,
+                                   maxReactionTypes)
             if postIsSensitive and reactionStr:
                 reactionStr = '<br>' + reactionStr
         postHtml = '    <div id="' + timelinePostBookmark + \