This commit introduces the skeleton of the chat thread UI. The
structure of the components looks like this. Its done this way
so the side panel can be used for other things as well if we wish,
not just for threads:
```
.main-chat-outlet
<ChatLivePane />
<ChatSidePanel>
<-- rendered with {{outlet}} -->
<ChatThread />
</ChatSidePanel>
```
Later on the `ChatThreadList` will be rendered here as well.
Now, when you go to a channel you can open a thread by clicking
on either the Open Thread message action button or by clicking on
the reply indicator. This will take you to a route like `chat/c/:slug/:channelId/t/:threadId`.
This works on mobile as well.
This commit includes basic serializers and routes for threads,
as well as a new `ChatThreadsManager` service in JS that caches
threads for a channel the same way the channel threads manager does.
The chat messages inside the thread are intentionally left out
until a later PR.
**NOTE: These changes are gated behind the site setting enable_experimental_chat_threaded_discussions
and the threading_enabled boolean on a ChatChannel**
Whenever we create a chat message that is `in_reply_to` another
message, we want to lazily populate the thread record for the
message chain.
If there is no thread yet for the root message in the reply chain,
we create a new thread with the appropriate details, and use that
thread ID for every message in the chain that does not yet have
a thread ID.
* Root message (ID 1) - no thread ID
* Message (ID 2, in_reply_to 1) - no thread ID
* When I as a user create a message in reply to ID 2, we create a thread and apply it to ID 1, ID 2, and the new message
If there is a thread for the root message in the reply chain, we
do not create one, and use the thread ID for the newly created chat
message.
* Root message (ID 1) - thread ID 700
* Message (ID 2, in_reply_to 1) - thread ID 700
* When I as a user create a message in reply to ID 2, we use the existing thread ID 700 for the new message
We also support passing in the `thread_id` to `ChatMessageCreator`,
which will be used when replying to a message that is already part of
a thread, and we validate whether that `thread_id` is okay in the context
of the channel and also the reply chain.
This work is always done, regardless of channel `thread_enabled` settings
or the `enable_experimental_chat_threaded_discussions` site setting.
This commit does not include a large data migration to backfill threads for
all existing reply chains, its unnecessary to do this so early in the project,
we can do this later if necessary.
This commit also includes thread considerations in the `MessageMover` class:
* If the original message and N other messages of a thread is moved,
the remaining messages in the thread have a new thread created in
the old channel and are moved to it.
* The reply chain is not preserved for moved messages, so new threads are
not created in the destination channel.
In addition to this, I added a fix to also clear the `in_reply_to_id` of messages
in the old channel which are moved out of that channel for data cleanliness.
Whenever we create a chat message that is `in_reply_to` another
message, we want to lazily populate the thread record for the
message chain.
If there is no thread yet for the root message in the reply chain,
we create a new thread with the appropriate details, and use that
thread ID for every message in the chain that does not yet have
a thread ID.
* Root message (ID 1) - no thread ID
* Message (ID 2, in_reply_to 1) - no thread ID
* When I as a user create a message in reply to ID 2, we create a thread and apply it to ID 1, ID 2, and the new message
If there is a thread for the root message in the reply chain, we
do not create one, and use the thread ID for the newly created chat
message.
* Root message (ID 1) - thread ID 700
* Message (ID 2, in_reply_to 1) - thread ID 700
* When I as a user create a message in reply to ID 2, we use the existing thread ID 700 for the new message
We also support passing in the `thread_id` to `ChatMessageCreator`,
which will be used when replying to a message that is already part of
a thread, and we validate whether that `thread_id` is okay in the context
of the channel and also the reply chain.
This work is always done, regardless of channel `thread_enabled` settings
or the `enable_experimental_chat_threaded_discussions` site setting.
This commit does not include a large data migration to backfill threads for
all existing reply chains, its unnecessary to do this so early in the project,
we can do this later if necessary.
This commit also includes thread considerations in the `MessageMover` class:
* If the original message and N other messages of a thread is moved,
the remaining messages in the thread have a new thread created in
the old channel and are moved to it.
* The reply chain is not preserved for moved messages, so new threads are
not created in the destination channel.
In addition to this, I added a fix to also clear the `in_reply_to_id` of messages
in the old channel which are moved out of that channel for data cleanliness.
This commit fleshes out and adds functionality for the new `#hashtag` search and
lookup system, still hidden behind the `enable_experimental_hashtag_autocomplete`
feature flag.
**Serverside**
We have two plugin API registration methods that are used to define data sources
(`register_hashtag_data_source`) and hashtag result type priorities depending on
the context (`register_hashtag_type_in_context`). Reading the comments in plugin.rb
should make it clear what these are doing. Reading the `HashtagAutocompleteService`
in full will likely help a lot as well.
Each data source is responsible for providing its own **lookup** and **search**
method that returns hashtag results based on the arguments provided. For example,
the category hashtag data source has to take into account parent categories and
how they relate, and each data source has to define their own icon to use for the
hashtag, and so on.
The `Site` serializer has two new attributes that source data from `HashtagAutocompleteService`.
There is `hashtag_icons` that is just a simple array of all the different icons that
can be used for allowlisting in our markdown pipeline, and there is `hashtag_context_configurations`
that is used to store the type priority orders for each registered context.
When sending emails, we cannot render the SVG icons for hashtags, so
we need to change the HTML hashtags to the normal `#hashtag` text.
**Markdown**
The `hashtag-autocomplete.js` file is where I have added the new `hashtag-autocomplete`
markdown rule, and like all of our rules this is used to cook the raw text on both the clientside
and on the serverside using MiniRacer. Only on the server side do we actually reach out to
the database with the `hashtagLookup` function, on the clientside we just render a plainer
version of the hashtag HTML. Only in the composer preview do we do further lookups based
on this.
This rule is the first one (that I can find) that uses the `currentUser` based on a passed
in `user_id` for guardian checks in markdown rendering code. This is the `last_editor_id`
for both the post and chat message. In some cases we need to cook without a user present,
so the `Discourse.system_user` is used in this case.
**Chat Channels**
This also contains the changes required for chat so that chat channels can be used
as a data source for hashtag searches and lookups. This data source will only be
used when `enable_experimental_hashtag_autocomplete` is `true`, so we don't have
to worry about channel results suddenly turning up.
------
**Known Rough Edges**
- Onebox excerpts will not render the icon svg/use tags, I plan to address that in a follow up PR
- Selecting a hashtag + pressing the Quote button will result in weird behaviour, I plan to address that in a follow up PR
- Mixed hashtag contexts for hashtags without a type suffix will not work correctly, e.g. #ux which is both a category and a channel slug will resolve to a category when used inside a post or within a [chat] transcript in that post. Users can get around this manually by adding the correct suffix, for example ::channel. We may get to this at some point in future
- Icons will not show for the hashtags in emails since SVG support is so terrible in email (this is not likely to be resolved, but still noting for posterity)
- Additional refinements and review fixes wil
