I have a Reaction resource which is used to store likes and blocks in a social media context (a user can like an other user). I want to create a like action but get the following error. How can I fix this?
iex(12)> like = Animina.Accounts.Reaction
|> Ash.Changeset.for_create(:like, %{sender_id: user2.id, receiver_id: stefan.id})
|> Animina.Accounts.Reaction.create!()
** (Protocol.UndefinedError) protocol Enumerable not implemented for #Ash.Changeset<action_type: :create, action: :like, attributes: %{sender_id: "207a829e-2464-42f7-8257-f4fa482fc7c2", receiver_id: "096da9ff-bcf7-49a1-8cba-f98413f37cab"}, relationships: %{},
The resource:
defmodule Animina.Accounts.Reaction do
@moduledoc """
This is the Reaction module which we use to manage likes, block, etc.
"""
use Ash.Resource,
data_layer: AshPostgres.DataLayer
attributes do
uuid_primary_key :id
attribute :name, :atom do
constraints one_of: [:like, :block]
allow_nil? false
end
create_timestamp :created_at
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
actions do
defaults [:create, :read, :destroy]
create :like do
accept [:sender_id, :receiver_id]
change set_attribute(:name, :like)
end
end
code_interface do
define_for Animina.Accounts
define :read
define :create
define :destroy
define :by_id, get_by: [:id], action: :read
define :by_sender_id, get_by: [:sender_id], action: :read
define :by_receiver_id, get_by: [:receiver_id], action: :read
end
identities do
identity :unique_reaction, [:sender_id, :receiver_id, :name]
end
postgres do
table "reactions"
repo Animina.Repo
references do
reference :sender, on_delete: :delete
reference :receiver, on_delete: :delete
end
end
end
Looks like you are mixing up the changeset-based resource creation flow and the code interface one. Once you have a changeset, you just pipe it into ‘Ash.create!’.
Sorry about the terse reply, typing on my phone right now
I want to call the :like action which I defined here:
actions do
defaults [:create, :read, :destroy]
create :like do
accept [:sender_id, :receiver_id]
change set_attribute(:name, :like)
end
end
If I just call Animina.Accounts.Reaction.create!/1 I get this error because the name attribute is required.
iex(5)> Animina.Accounts.Reaction.create!(%{sender_id: stefan.id, receiver_id: stefan.id})
** (Ash.Error.Invalid) Input Invalid
* attribute name is required
(ash 2.18.2) lib/ash/api/api.ex:2711: Ash.Api.unwrap_or_raise!/3
How can I call the like action? I tried this but that didn’t work:
iex(5)> Animina.Accounts.Reaction.create!(:like, %{sender_id: stefan.id, receiver_id: stefan.id})
** (FunctionClauseError) no function clause matching in Keyword.split/2
The following arguments were given to Keyword.split/2:
# 1
%{
receiver_id: "16d7d94b-3975-4220-afc6-83d0ad009c9e",
sender_id: "16d7d94b-3975-4220-afc6-83d0ad009c9e"
}
# 2
[:changeset, :actor, :tenant, :authorize?, :tracer]
Attempted function clauses (showing 1 out of 1):
def split(keywords, keys) when is_list(keywords) and is_list(keys)
(elixir 1.16.0) lib/keyword.ex:1179: Keyword.split/2
(animina 0.1.0) deps/ash/lib/ash/code_interface.ex:536: Animina.Accounts.Reaction.create!/2
I believe that you mean to be calling the function on the api, not the resource. The create function on the resource is defined by your define :create in the code interface, and its meant to cal specifically the create action.
Now I am totally lost. What is the cleanest solution for the given problem? I want for the future external JSON-API a way to create a like the most secure way. What is the best way to do so?
You have a :like action, and so how you call it in code can’t and won’t affect how the JSON:API behaves (which is why Ash is the way that it is).
There are three ways to call this like action in code, one of which is no longer available in 3.0. AshJsonApi will be unaffected by your choice here. You should choose #1, but I’m including 2 & 3 informationally.
You can define a code interface function as @joelpaulkoch says. This is the recommended approach. For this, you’d define something like this:
define :like, args: [:sender_id, :receiver_id]
and call it like YourResource.like(sender_id, receiver_id).
NOTE: In 3.0 this can be done in one additional way, where you define the code interface on the domain. It’s not relevant here, see the upgrade guide for more.
You can build a changeset and then call YourApi.create not YourApi.Resource.create. This is deprecated in 3.0
You can build a changeset and then call Ash.create. However, this only works if you have configured an api when using the resource, i.e use Ash.Resource, api: Api. (because we have to know the api). This is essentially a compatibility feature to make upgrading to 3.0. Don’t bother with it right now. When you are interested in upgrading to 3.0, the upgrade guide will explain how to make this change.
