Support Join query in filterOptions

[tsemachh]

Joins are great , yet many of the usages of joins are not possible today due to the fact that we can't use join fields with filterOptions.
filterOptions eventually use Rest API which supports join , so we need to add to filterOptions the capability to filter by join as we have in the rest API.
See:
https://discord.com/channels/967097582721572934/1300760003250094103
https://discord.com/channels/967097582721572934/1300810327574708346

[DanRibbens]

I'm making sure I understand this correctly. You want to be able to configure filterOptions on the join field so that you only surface the docs that match a certain query in the edit view join table.

I can see how that could be useful.

Is that right?

[akhrarovsaid]

Hey @DanRibbens,

Spot on - I believe this is exactly what this feature request is seeking. We have had a few users on the Discord inquire about this exact feature in recent memory for various use-cases.

[tsemachh]

@DanRibbens correct
Imagine a researcher which gathers medias on topic x
Then author takes the data to publish article and the media in the article comes from.the author media on that topic

[DanRibbens]

#8973

[tsemachh]

@DanRibbens I replied in #8973 (comment)
You got me right besides the fact that the query is not static it's context sensitive based on the data provided in the collection field level.
aka having it in join field level will just allow us static filtering , while filterOptions provides dynamic filtering example:

              {
                type: 'upload',
                name: 'gallery',
                relationTo: 'media',
                filterOptions: async (args: FilterOptionsProps<PublicTopic>) => {
                  'use server'
                    return { belongToTopic: { equals: args.data.topicEntity } }
                },
              },

While author flow is to select the topicEntity and then all media is filtered by media which has a join field belongToTopic