Rasa: Issue in the Slack connector

[JiteshGaikwad]

Rasa version: 1.9.6

Python version: Python 3.7.6

Operating system (windows, osx, ...): windows

Issue: The Slack connector is not able to handle the button payload response from the slack.

Error (including full traceback):

 File "c:\users\jitesh\appdata\local\programs\python\python37\lib\site-packages\sanic\request.py", line 173, in load_json
    self.parsed_json = loads(self.body)
ValueError: Expected object or value

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\users\jitesh\appdata\local\programs\python\python37\lib\site-packages\sanic\app.py", line 976, in handle_request
    response = await response
  File "c:\users\jitesh\appdata\local\programs\python\python37\lib\site-packages\rasa\core\channels\slack.py", line 356, in webhook 
    metadata = self.get_metadata(request)
  File "c:\users\jitesh\appdata\local\programs\python\python37\lib\site-packages\rasa\core\channels\slack.py", line 329, in get_metadata
    slack_event = request.json
  File "c:\users\jitesh\appdata\local\programs\python\python37\lib\site-packages\sanic\request.py", line 167, in json
    self.load_json()
  File "c:\users\jitesh\appdata\local\programs\python\python37\lib\site-packages\sanic\request.py", line 177, in load_json
    raise InvalidUsage("Failed when parsing body as json")
sanic.exceptions.InvalidUsage: Failed when parsing body as json

Below is the output of the error in slack:

when I tried to find where the issue lies, I got to know that the request object that was received from slack was in the req.form and the issue occurs when getting the metadata value on the below line:

https://github.com/RasaHQ/rasa/blob/002b892f573541b42a05b783df64424f959ff9e8/rasa/core/channels/slack.py#L356
since the get_metadata function uses req.json to set the values for metadata and req.json isn't there so it throws the above error.

So as a workaround, I tried to update the connector and it worked for me:

        @slack_webhook.route("/webhook", methods=["GET", "POST"])
        async def webhook(request: Request) -> HTTPResponse:
            if request.form:
                output = request.form
                payload = json.loads(output["payload"][0])
                if self._is_interactive_message(payload):
                    sender_id = payload["user"]["id"]
                    text = self._get_interactive_response(payload["actions"][0])
                    if text is not None:
                        # metadata = self.get_metadata(request)
                        out_channel = payload["channel"]["id"]
                        users = payload["user"]["id"]
                        metadata = {'out_channel': out_channel, 'users': users}
                        return await self.process_message(
                            request, on_new_message, text, sender_id, metadata
                        )
                    elif payload["actions"][0]["type"] == "button":
                        # link buttons don't have "value", don't send their clicks to bot
                        return response.text("User clicked link button")
                return response.text(
                    "The input message could not be processed.", status=500
                )

I am getting the values for metadata from the payload.

Below is the output from the slack after updating the connector:

I don't know whether it's a reliable workaround solution😅 would like to know your thoughts on this 😄

[sara-tagger]

Thanks for the issue, @degiz will get back to you about it soon!

You may find help in the docs and the forum, too 🤗

[iicky]

I am also having this same exact issue when processing a Slack button. I'll try and test out the workaround as well to see if it works for me.

[vipuldarkknight]

I was also facing the same issue with slack, so when I was looking at where the problem lies, I got to know the same thing which @JiteshGaikwad pointed out, as the metadata option was an optional one for the functions thereafter so I commented that line and initialized metadata to an empty dictionary and that seems to work for me. Please look into this matter.

Also, I think if you are initializing the metadata as done for request.json you should do like,
lst = [ ]
lst.append( payload["message"]["user"] )
out_channel = payload["channel"]["id"]
users = lst
should be used, you can see the similarity with the get_metadata function for request.json

[degiz]

@JiteshGaikwad @vipuldarkknight

thanks a lot for reporting the bug! I can also reproduce the exception. Since you already found a fix, would you consider creating a PR with a fix?

[vipuldarkknight]

@JiteshGaikwad @vipuldarkknight

thanks a lot for reporting the bug! I can also reproduce the exception. Since you already found a fix, would you consider creating a PR with a fix?

how can we do that?

[degiz]

@vipuldarkknight standard Github way - you fork the project, commit a change, and open the PR towards Rasa-master 😄

[vipuldarkknight]

@vipuldarkknight standard Github way - you fork the project, commit a change, and open the PR towards Rasa-master

yeah I have opened a PR proposing the same changes that I suggested earlier