I'm building a chatbot with Telegram and Google Dialogflow. When I integrate Dialogflow into Telegram via the Dialogflow "Integrations" tab, Dialogflow registers as a Webbhook service to intercept all received Telegram messages. Unfortunately, I cannot act on non-text messages like stickers, images and Telegram payment checkout messages.
I wish Dialogflow would forward all the received messages to my custom fulfillment webhook in the Fallback intent. In my webhook, I would be able to parse the received body and act on the unsupported telegram messages accordingly.
I know that there is a FACEBOOK_MEDIA event in Dialogflow. This event is fired when an image is sent via a Facebook messenger to Dialogflow. Is there something like a TELEGRAM_MEDIA or even a TELEGRAM_UNSUPPORTED event available?
I would really like to be able to act on more than just text messages in Dialogflow.
Do I need to add another layer between Telegram and Dialogflow to be able to act on all Telegram messages?
What I have analyzed so far:
I forward all Google Dialogflow interaction logs to Google Cloud stackdriver. It seems as if non-text messages are completely ignored by Dialogflow. I see no log entry at all when I send a non-text message to my telegram bot. On the other hand, when I send a text, the log and its JSON payload appears immediately in the stackdriver.
I created a fallback intent in Dialogflow and enabled "Enable webhook call for this intent" in the Fulfillment section. Unfortunately, my fulfillment function doesn't fire on any non-text events. Dialogflow blocks it in the first place.