compose: Update compose placeholder text if recipients are changed.

[vinitS101]

The placeholder text is now updated every time recipients of Private Messages are changed (added or removed).

Fixes #15897.

GIFs or Screenshots:

For PMs:

EDIT:

For stream messages:

[zulipbot]

Hello @zulip/server-compose members, this pull request was labeled with the "area: compose" label, so you may want to check it out!

[Gittenburg]

Do you also update the placeholder when changing which stream / topic you reply to? Because that missing is also part of #15897 and your commits message 64b380b only speaks of PMs.

[vinitS101]

@Gittenburg Those already get updated when you move to the compose text-area.

Started a discussion on czo - https://chat.zulip.org/#narrow/stream/6-frontend/topic/compose.20placeholder.20text/near/957729

[Gittenburg]

The PM placeholder also already updates when you focus the textarea. The problem I raise in my issue is that incorrect placeholders are confusing. In my opinion we could also just fix the placeholder to always be "Message" no matter whom / where you send it. That would still be better than having inconsistencies in the UI.

[ryanreh99]

Hi, I don't think we should add dependencies to the user_pill and input_pill files.

As we have the onPillCreate and onPillRemove functions which can be attached to the compose_pm_pill object.

[timabbott]

@vinitS101 ping on updating this.

[vinitS101]

There was a bug in input_pill.js where onPillCreate did not get updated when a user pill was added in the PM compose box using typeheads. The second the commit fixes that issue, thanks to @ryanreh99.

The final commit is pending some tests, but works as expected (same as the GIF in the first comment). I'll add these tests and also a commit that updates the placeholder text for stream messages when the stream name is update.

@timabbott

[vinitS101]

Added a commit that updates the placeholder text for stream name changes. Also added a GIF of the same to the first comment.

[vinitS101]

@timabbott please review this PR.

[timabbott]

I merged the first commit. @ryanreh99 can you review the onPillCreate change?

@vinitS101 it might help for you to expand that commit's commit message to make clear (1) exactly what the bug was and (2) how you're confident that nothing was relying on the old behavior; it's not obvious to me on a quick look.

[ryanreh99]

The commit lgtm.
Previous behaviour was that the onPillCreate function was called after the individual pill object was created.
Now, we call it after creating and adding it to the pill container.

The commit title should be renamed to input pills instead of user_pills.

[vinitS101]

Rebased and updated the commit messages to better explain the current and changed behavior.

[timabbott]

Great, merged, thanks @vinitS101!

[andersk]

input_pill.onPillCreate and input_pill.onPillRemove don’t exist. (input_pill is the module, not an instance.) What happened here?

[timabbott]

@ryanreh99 @vinitS101 it'd be great if one of you can figure out what the bug was with those onPillCreate methods; they were deleted in 03c409d, but it's possible another fix would be better.