Feature Request: Please consider implementing 'snippet' support for the Slack connector

[law]

Description

I'm developing a skill that occasionally will return a LARGE amount of text. Rather than flood the public room, it would be nice if the Opsdroid Slack connector had the ability to send a message as a 'snippet' so a small preview of the larger output would be shown, and users would have the ability to click through to see the full data-dump.

Steps to Reproduce

Right now, await message.respond(f"regular message") only sends a regular Slack message. There is the ability to send 'rich' messages with event.respond(Blocks([])), but an event.respond(Snippet([])) that utilizes the https://api.slack.com/types/file type or similar would be ideal.

Expected Functionality

Opsdroid should have the option of sending large messages as a 'snippet' or 'file' type, for cleaner displays of large amounts of data in public channels.

• Opsdroid version: 0.19.0
• Python version: 3.8.4
• OS/Docker version:

Additional Details

Any other details you wish to include such as screenshots, console messages, etc.

[FabioRosado]

I have just recently written a quick thing using NLTK to get a summary/snippet of a large block of text. I wonder if this should be done on a skill level - although I'm not sure how that would work... Maybe we could create an event that is fired when the text has more than x number of lines? 🤔

Unless you don't really care as much about a summary of that large block of test and instead you just want the first x words of the test? 🤔

[jacobtomlinson]

I think in this case we want to upload the text to Slack as a File object. In Slack a text file under 1MB is referred to as a snippet and is previewed in the chat.

We already have the File event which represents bytes objects

opsdroid/opsdroid/events.py

Lines 336 to 337 in 1e1544d

	class File(Event):
	"""Event class to represent arbitrary files as bytes."""

We should add a new handler to the Slack connector which can send File events. Something like this.

    @register_event(opsdroid.events.File)
    async def _send_file(self, file_event):
        return await self.slack.api_call(
            "files.upload",
            data={"channels": file_event.target, "content": await file_event.get_file_bytes(), "filetype": await file_event.get_mimetype(), "filename": file_event.name},
        )

Then in order to send this from your skill you would need to construct a File event with a bytearray of the text.

await message.respond(File(file_bytes=f"my long string".encode("utf-8"), mimetype="text", name="mysnippet.txt"))

This would allow the use case here of sending long messages as snippets, but also uploading of files in general.

We could also add a Snippet event to opsdroid.connector.slack.events which subclasses File and provides a nicer interface for converting to bytes, setting the mimetype, etc.

await message.respond(Snippet(f"my long string", type="text"))

Allowing the type to be set means that the user could specify the Slack file type. Perhaps auto would be a sensible default here.

[vxe]

is uploading files as snippets still on the roadmap?

[pmaresca]

I'm attempting to take a stab at this, we'll see how it goes

[pmaresca]

@jacobtomlinson I put together a small PR based on your input, any additional feedback/guidance you have would be appreciated.