Message handling fixes

Don't create a message object for posts without text.  Additionally, use
the accepted character replacements for unicode characters.

Signed-off-by: Anna Schumaker <Anna@OcarinaProject.net>

slack/chat.py

@@ -25,7 +25,7 @@ class Message:
         self.__ts   = json["ts"]
         self.__time = datetime.fromtimestamp(float(self.__ts))
         self.__user = users.info(json.get("user", None))
-        self.__text = [ json["text"].encode("utf-8").decode("latin-1") ]
+        self.__text = [ json["text"].encode("utf-8").decode(errors="replace")]
 
     def __lt__(self, other):
         return self.__time < other.__time

slack/threads.py

@@ -16,8 +16,8 @@ class Thread:
     def __init__(self, json):
         self.__id      = json.get("id", 0)
         self.__name    = json.get("name", "").title()
-        self.__topic   = json["topic"].get("value", "").encode("utf-8").decode("latin-1")
-        self.__purpose = json["purpose"].get("value", "").encode("utf-8").decode("latin-1")
+        self.__topic   = json["topic"].get("value", "").encode("utf-8").decode(errors="replace")
+        self.__purpose = json["purpose"].get("value", "").encode("utf-8").decode(errors="replace")
         self.__unread  = json.get("unread_count", None)
         self.__last_ts = json.get("last_read", None)
 
@@ -49,7 +49,8 @@ class Thread:
         # Read original message list
         o_list = []
         for message in self.do_fetch_messages(self.__last_ts):
-            o_list += [ chat.Message(message) ]
+            if message["text"] != None:
+                o_list += [ chat.Message(message) ]
         o_list.sort()
 
         # Merge together messages from the same user