updates code to reflect changes in mattmakai/fullstackpython.com#145

requirements.txt

@@ -1 +1 @@
-slackclient==1.0.0
+slackclient>=1.1.0

starterbot.py

@@ -1,57 +1,70 @@
 import os
 import time
+import re
 from slackclient import SlackClient
 
 
-# starterbot's ID as an environment variable
-BOT_ID = os.environ.get("BOT_ID")
+# instantiate Slack client
+slack_client = SlackClient(os.environ.get('SLACK_BOT_TOKEN'))
+# starterbot's user ID in Slack: value is assigned after the bot starts up
+starterbot_id = None
 
 # constants
-AT_BOT = "<@" + BOT_ID + ">"
+RTM_READ_DELAY = 1 # 1 second delay between reading from RTM
 EXAMPLE_COMMAND = "do"
+MENTION_REGEX = "^<@(|[WU].+)>(.*)"
 
-# instantiate Slack & Twilio clients
-slack_client = SlackClient(os.environ.get('SLACK_BOT_TOKEN'))
+def parse_bot_commands(slack_events):
+    """
+        Parses a list of events coming from the Slack RTM API to find bot commands.
+        If a bot command is found, this function returns a tuple of command and channel.
+        If its not found, then this function returns None, None.
+    """
+    for event in slack_events:
+        if event["type"] == "message" and not "subtype" in event:
+            user_id, message = parse_direct_mention(event["text"])
+            if user_id == starterbot_id:
+                return message, event["channel"]
+    return None, None
 
+def parse_direct_mention(message_text):
+    """
+        Finds a direct mention (a mention that is at the beginning) in message text
+        and returns the user ID which was mentioned. If there is no direct mention, returns None
+    """
+    matches = re.search(MENTION_REGEX, message_text)
+    # the first group contains the username, the second group contains the remaining message
+    return (matches.group(1), matches.group(2).strip()) if matches else (None, None)
 
 def handle_command(command, channel):
     """
-        Receives commands directed at the bot and determines if they
-        are valid commands. If so, then acts on the commands. If not,
-        returns back what it needs for clarification.
+        Executes bot command if the command is known
     """
-    response = "Not sure what you mean. Use the *" + EXAMPLE_COMMAND + \
-               "* command with numbers, delimited by spaces."
+    # Default response is help text for the user
+    default_response = "Not sure what you mean. Try *{}*.".format(EXAMPLE_COMMAND)
+
+    # Finds and executes the given command, filling in response
+    response = None
+    # This is where you start to implement more commands!
     if command.startswith(EXAMPLE_COMMAND):
         response = "Sure...write some more code then I can do that!"
-    slack_client.api_call("chat.postMessage", channel=channel,
-                          text=response, as_user=True)
-
-
-def parse_slack_output(slack_rtm_output):
-    """
-        The Slack Real Time Messaging API is an events firehose.
-        this parsing function returns None unless a message is
-        directed at the Bot, based on its ID.
-    """
-    output_list = slack_rtm_output
-    if output_list and len(output_list) > 0:
-        for output in output_list:
-            if output and 'text' in output and AT_BOT in output['text']:
-                # return text after the @ mention, whitespace removed
-                return output['text'].split(AT_BOT)[1].strip().lower(), \
-                       output['channel']
-    return None, None
 
+    # Sends the response back to the channel
+    slack_client.api_call(
+        "chat.postMessage",
+        channel=channel,
+        text=response or default_response
+    )
 
 if __name__ == "__main__":
-    READ_WEBSOCKET_DELAY = 1 # 1 second delay between reading from firehose
-    if slack_client.rtm_connect():
-        print("StarterBot connected and running!")
+    if slack_client.rtm_connect(with_team_state=False):
+        print("Starter Bot connected and running!")
+        # Read bot's user ID by calling Web API method `auth.test`
+        starterbot_id = slack_client.api_call("auth.test")["user_id"]
         while True:
-            command, channel = parse_slack_output(slack_client.rtm_read())
-            if command and channel:
+            command, channel = parse_bot_commands(slack_client.rtm_read())
+            if command:
                 handle_command(command, channel)
-            time.sleep(READ_WEBSOCKET_DELAY)
+            time.sleep(RTM_READ_DELAY)
     else:
-        print("Connection failed. Invalid Slack token or bot ID?")
+        print("Connection failed. Exception traceback printed above.")