Display a list of allowed entries in a different channel's field for a selected author

Question

I get stucked. I've to do this: I've a channel "Projects" where a Super Author write a list of projects. I've another channel "Articles" where Authors can write articles and make a unique relationship with a single entry in "Projects" channel. But only Super Author can allow which Author can select that single project. So in a field in "Articles" entry for that author, it should be listed only allowed "Projects" entries for that author.

EX: There is S_A (Super Author), A_1 (Author 1), A_2 (Author 2). S_A make Prj_1, Prj_2, Prj_3 and assign that permissions:

Prj_1 -> A_1
Prj_2 -> A_1;A_2
Prj_3 -> A_2

A_1 when write an article in "Articles" channel can select from a dropdown only Prj_1 & Prj_2, and can't see Prj_3 in the list;

A_2A_1 when write an article in "Articles" channel can select from a dropdown only Prj_2 & Prj_3, and can't see Prj_1 in the list;

I've done this steps: I've created 3 different channels:

- Authors (with plug-in Profile:Edit); 
- Project;
- Articles;

In Projects i've created this channel fields: prj_author that is a Playa field to allow S_A to select allowed Authors.

In Articles i've created this channel fields: art_projects that is a Playa field to show all the entries in the "Projects" channel, but here i can't filter entries for the selected author in prj_author playa field.

Please can somebody can help me? I can offer a beer :D

Answer 1

You'll need to write a custom fieldtype to achieve this - I can't think of any existing fieldtypes that could accomplish this for you.

So in your fieldtype, you'd query exp_playa_relationships for all parent_entry_id's where where child_entry_id was equal to the entry_id associated with ee()->session->userdata('member_id'). (Not sure how Profile:Edit stores its Channel/Member relationships, but it's probably in a simple DB table.) Then, use that data to build a menu from there.

Very difficult to then pass this to a Playa field though - you'd be best off building your own dropdown menu.