[Feature] Filter dropdown options based on other dropdown selections

[bryce-seifert]

Describe the feature
Ability to filter dropdown options in actions / feedbacks based on other dropdown selections.

Usecases
For example, in the OBS module there are actions where there is a dropdown where you select a scene and a drop down to select a source. However, the source dropdown lists all the sources. It would be great if the second dropdown could only show sources from a particular scene.

More discussion in this Slack thread.

[krocheck]

@estilles anything you can think of for this given your experience on the isVisible feature?

[estilles]

@krocheck this is definitely doable. We've already done all the heavy lifting with isVisible.

[krocheck]

I had a hunch you'd say that ;)

[estilles]

I like this feature. I'll take this one on. :-)

[thedist]

The originally linked Slack thread has expired so I don't recall all of the suggestions, but this is a feature that I'd definitely like to see as I'm working on the Discord module and for join channel actions a user could potentially be in tens of guilds (servers), each with dozens of tens of channels, leading to a significant list of Dropdown choices. I currently order these by guild name then channel name, but being able to split them into 2 dropdown boxes and having the first dropdown (guild selection) filter the second (channels in that guild) would be a huge quality of life improvement.

My first thought about achieving something like this would be for up to 1 option having a 'setCategory' param, with all other options having a 'category' (or it being undefined). The frontend could then have a filter on each dropdown option to see if a category has been seen, and if so filter to options that have a matching category. This would be fully backwards compatible as an undefined setCategory would match all options that have an undefined category.

A more complex solution would be an additional 'filter' function that devs could optionally define on actions/functions, and allow more complex filtering solutions, even potentially filtering the options by params external to the options, such as enabling/disabling certain choices based on the current state of the instance.