This is extracted from https://github.com/discourse/discourse/pull/29129.
In some chat specs, we provide an array as a value for group lists like
`chat_allowed_groups`, which is wrong. This results in a value like
`"1|2|[3]"` instead of `"1|2|3"`.
This change allows us to distinguish between regular user generated chat messages and those created via the Chat SDK.
A new created_by_sdk boolean column is added to the Chat Messages table. When this value is true, we will not include the message in the user summary email that is sent to users.
Prior to this commit, only system users had this pass.
Another significant change of the PR, is to make membership of a channel the angular stone of the permission check to create/update/stop streaming a message. The idea being, if you are a member of a channel already we don't need to check if you can join it AGAIN.
We also have `Chat::AutoRemove::HandleCategoryUpdated` which will deal with permissions change so it's simpler and less prone to error to consider the membership as the only source of truth.
The TextCleaner step has been moved from chat message’s validation to create_message/update_message services. It allows us to easily tweak part of its behavior depending on the needs.
For example we will now disable strip_whitespaces by default when streaming messages as we want to keep newlines and spaces at the end of the message.
Forcing a thread will work even in channel which don't have `threading_enabled` or in direct message channels.
For now this feature is only available through the `ChatSDK`:
```ruby
ChatSDK::Message.create(in_reply_to_id: 1, guardian: guardian, raw: "foo bar baz", channel_id: 2, force_thread: true)
```
```ruby
ChatSDK::Message.start_stream(message_id: 1, guardian: guardian)
ChatSDK::Message.stream(raw: "foo", message_id: 1, guardian: guardian)
ChatSDK::Message.stream(raw: "bar", message_id: 1, guardian: guardian)
ChatSDK::Message.stop_stream(message_id: 1, guardian: guardian)
```
Generally speaking only admins or owners of the message can interact with a message. Also note, Streaming to an existing message with a different user won't change the initial user of the message.
This commit introduces the possibility to stream messages. To allow plugins to use streaming this commit also ships a `ChatSDK` library to allow to interact with few parts of discourse chat.
```ruby
ChatSDK::Message.create_with_stream(raw: "test") do |helper|
5.times do |i|
is_streaming = helper.stream(raw: "more #{i}")
next if !is_streaming
sleep 2
end
end
```
This commit also introduces all the frontend parts:
- messages can now be marked as streaming
- when streaming their content will be updated when a new content is appended
- a special UI will be showing (a blinking indicator)
- a cancel button allows the user to stop the streaming, when cancelled `helper.stream(...)` will return `false`, and the plugin can decide exit early
