How I can handle a many to many relationship between two diferent apis?

[hackemateninja]

Hello I am trying to do a many to many association between resources from two diferent apis this is my registry from both sides

defmodule Hatamoto.Accounts.Registry do
  alias Hatamoto.Accounts.{Client, ClientBranch, Company, Employee, Subscription, Token}
  use Ash.Registry

  entries do
    entry Client
    entry ClientBranch
    entry Company
    entry Employee
    entry Subscription
    entry Token
  end
end

defmodule Hatamoto.Engine.Registry do
  alias Hatamoto.Engine.{
    Bill,
    Branch,
    Delivery,
    Discount,
    Notification,
    Product,
    Reminder,
    Sale,
    Stock,
    Vehicle
  }

  use Ash.Registry

  entries do
    entry Bill
    entry Branch
    entry Delivery
    entry Discount
    entry Notification
    entry Product
    entry Reminder
    entry Sale
    entry Stock
    entry Vehicle
  end
end

This is my relationship on client module

many_to_many :branches, Hatamoto.Engine.Branch do
     api Hatamoto.Engine
      through Hatamoto.Accounts.ClientBranch
      source_attribute_on_join_resource :client_id
      destination_attribute_on_join_resource :branch_id
    end

this is my relationship from branch

many_to_many :clients, Hatamoto.Accounts.Client do
      api Hatamoto.Accounts
      through Hatamoto.Accounts.ClientBranch
      source_attribute_on_join_resource :branch_id
      destination_attribute_on_join_resource :client_id
    end

and this is my relationship from clientBranch resouse

relationships do
    belongs_to :client, Hatamoto.Accounts.Client do
      primary_key? true
      allow_nil? false
    end

    belongs_to :branch, Hatamoto.Engine.Branch do
      primary_key? true
      allow_nil? false
    end
  end

But i got this error

Resource Hatamoto.Accounts.ClientBranch is not accepted by api Hatamoto.Engine for autogenerated join relationship: :branches_join_assoc

Relationship was generated by the many_to_many relationship :branches

If the through resource Hatamoto.Accounts.ClientBranch is not accepted by the same
api as the destination resource Hatamoto.Engine.Branch,
then you must define that relationship manually. To define it manually, add the following to your
relationships:

has_many :branches_join_assoc, Hatamoto.Accounts.ClientBranch do
  # configure the relationship attributes
  ...
end

You can use a name other than :branches_join_assoc, but if you do, make sure to
add that to :branches, i.e

many_to_many :branches_join_assoc, Hatamoto.Accounts.ClientBranch do
  ...
  join_relationship_name :your_new_name
end

[zachdaniel]

The error message describes the process. You'll need to add define the underlying has_many relationship manually, and configure the api of that relationship accordingly.

[hackemateninja]

are there any examples of code that you can provide me, please?

[zachdaniel]

given this relationship, where the through resource is in the source api not in Other.Api

many_to_many :friends, User do
  through FriendLink
  ...
  api Other.Api
end

you can split the has_many relationship out with a different api configured (or likely in your case, no api configured)

has_many :friend_links, FriendLink do
  ...
  # don't configure an api, since its in the same source api
end

many_to_many :friends, Friend do
  ...
  join_relationship 
end