How to create and destroy likes and blocks?

I have a social media setup where a User resource can like or block an other User resource. Here is the beginning of the resource:

defmodule Animina.Accounts.Reaction do 
  use Ash.Resource,
    data_layer: AshPostgres.DataLayer

  attributes do
    uuid_primary_key :id

    attribute :name, :atom do
      constraints one_of: [:like, :block]
    end
  end

  relationships do
    belongs_to :sender, Animina.Accounts.User do
      allow_nil? false
      attribute_writable? true
    end

    belongs_to :receiver, Animina.Accounts.User do
      allow_nil? false
      attribute_writable? true
    end
  end

I want to like, unlike, block and unblock from within our own code and open an external JSON-API for 3rd party software to do the same.

Is it a good idea to create custom actions (like, unlike, block and unblock) for that? If yes, how? If no, why?

The documentation is too abstract for a mediocre programmer like me who works best with examples.

Yes, you should create “semantic actions”, i.e like, unlike, block, unblock over create, update, and destroy. When you connect AshJsonApi, you will tell it which actions to make available over the JSON:API.

1 Like

Is it best/cleanest to do this with this resource (the resource which gets created) or would it be better to create those actions into the User resource since I want to block/like a user?

There will never be exactly one right answer for this question that applies in all cases, but in Ash(especially in 3.0 with code interfaces on the domain), you are free to define actions in the “most structurally convenient” way, and then expose consistent interfaces. In other words, callers don’t care where the action is defined. Since like creates a Like, it’s easiest to define it as a create action on that resource. Same for destroy.

So, in short, best to define on the resource you’re manipulating directly, as opposed to defining it on a conceptually related thing. You’re are “liking a user”, but mechanically that is “creating a like”. If you end up wanting to make an action on user that delegates to this action, you’ll need this one anyway, so start there.

1 Like