Ash Framework•3y ago

Proxying actions to other actions

I've found it a useful pattern to do some transformations that then proxy the remainder of the work to another action—often the primary action of its type. The way I'm doing that is roughly:

actions do
  create :upstream do
    change fn cs, ctx ->
      # do some upstream stuff
      Session
      |> Changeset.new
      |> Changeset.for_action(:create, %{param: value}, Map.to_list ctx)
    end
  end
end

actions do
  create :upstream do
    change fn cs, ctx ->
      # do some upstream stuff
      Session
      |> Changeset.new
      |> Changeset.for_action(:create, %{param: value}, Map.to_list ctx)
    end
  end
end

I've started getting a lot of the following:

warning: Changeset has already been validated for action :upstream.

In the future, this will become an error.

For safety, we prevent any changes after that point because they will bypass validations or other action logic.. To proceed anyway,
you can use `set_argument/3`. However, you should prefer a pattern like the below, which makes
any custom changes *before* calling the action.

  Resource
  |> Ash.Changeset.new()
  |> Ash.Changeset.set_argument(...)
  |> Ash.Changeset.for_create(...)

warning: Changeset has already been validated for action :upstream.

In the future, this will become an error.

For safety, we prevent any changes after that point because they will bypass validations or other action logic.. To proceed anyway,
you can use `set_argument/3`. However, you should prefer a pattern like the below, which makes
any custom changes *before* calling the action.

  Resource
  |> Ash.Changeset.new()
  |> Ash.Changeset.set_argument(...)
  |> Ash.Changeset.for_create(...)

Is there a preferred way to execute this pattern? It does seem like I'm doing something quite like what the message recommends.

37 Replies

ZachDaniel•3y ago

So the problem is that you're returning a changeset for the wrong action What you want is a manual action

manual fn changeset, _ -> 
  __MODULE__
  |> Changeset.for_action(:create, changeset.attributes)
  |> Api.create()
  
end

manual fn changeset, _ -> 
  __MODULE__
  |> Changeset.for_action(:create, changeset.attributes)
  |> Api.create()
  
end

would be one way to go about it There is generally no need to use Changeset.new

\ ឵឵឵OP•3y ago

Tbh I just added that to check if it would silence the warning 😂 Ok, so it would be better to use a manual for this, that's fair. I do recall thinking it seemed a little suspect to return a changeset for a different action 🙂 Would this still need Map.to_list ctx to thread through the calling context, or is that happening somewhere else?

ZachDaniel•3y ago

Yeah, you would still need that kind of thing

\ ឵឵឵OP•3y ago

Right on, cheers!

ZachDaniel•3y ago

Might need to make a helper for doing that kind of thing because if we ever add a key to the context that isn't a valid option to new changesets, it would break that code

\ ឵឵឵OP•3y ago

Thanks for the warning, I'll start wrapping them up from now on.

ZachDaniel•3y ago

Yeah, maybe do something like Map.take(...) |> Map.to_list() and take the keys you know about

\ ឵឵឵OP•3y ago

Actually I was experimenting with several options for this at one point; one of the reasons I ended up on this was because if I do it the other way, I'm getting:

[warning] Missed 1 notifications in action App.Post.create_special.

This happens when the resources are in a transaction, and you did not pass
`return_notifications?: true`. If you are in a changeset hook, you can
return the notifications. If not, you can send the notifications using
`Ash.Notifier.notify/1` once your resources are out of a transaction.

[warning] Missed 1 notifications in action App.Post.create_special.

This happens when the resources are in a transaction, and you did not pass
`return_notifications?: true`. If you are in a changeset hook, you can
return the notifications. If not, you can send the notifications using
`Ash.Notifier.notify/1` once your resources are out of a transaction.

ZachDaniel•3y ago

Yep, so if you add return_notifications?: true option, it will return them alongside the actual result lemme check something real quick Yeah so you can return {:ok, result, %{notifications: notifications}} from manual create So you'd do something like:

case Api.create(changeset, Keyword.put(..., :return_notifications?, true)) do
  {:ok, result, notifications} -> {:ok, result, %{notifications: notifications}}
  {:error, error} -> {:error, error}
end

case Api.create(changeset, Keyword.put(..., :return_notifications?, true)) do
  {:ok, result, notifications} -> {:ok, result, %{notifications: notifications}}
  {:error, error} -> {:error, error}
end

I'm going to fix the need for that before too long, we can automatically gather up notifications Just need to do it 🙂 Might be a 3.0 thing

\ ឵឵឵OP•3y ago

Nice! That would be great. I'm still getting the same warning, though, wondering if it might be somewhere else:

  def nested_ctx(ctx) do
    ctx
    |> Map.take([:actor, :context])
    |> Map.put(:return_notifications?, true)
    |> Map.to_list
  end

  def nested_ctx(ctx) do
    ctx
    |> Map.take([:actor, :context])
    |> Map.put(:return_notifications?, true)
    |> Map.to_list
  end

          case Post.create(%{...}, nested_ctx ctx) do
            {:ok, result, notes} ->
              {:ok, result, %{notifications: notes}}

            err ->
              err
          end

          case Post.create(%{...}, nested_ctx ctx) do
            {:ok, result, notes} ->
              {:ok, result, %{notifications: notes}}

            err ->
              err
          end

Wait a sec Thought it might be coming from the error branch, but seems ok:

            {:error, Ash.Error.to_ash_error("unable to create post")}

            {:error, Ash.Error.to_ash_error("unable to create post")}

ZachDaniel•3y ago

🤔 Does it give you a stacktrace in the warning?

\ ឵឵឵OP•3y ago

Yep

(elixir 1.14.4) lib/process.ex:773: Process.info/2
(ash 2.6.31) lib/ash/actions/helpers.ex:220: Ash.Actions.Helpers.warn_missed!/3
(ash 2.6.31) lib/ash/actions/update.ex:175: Ash.Actions.Update.add_notifications/6
(ash 2.6.31) lib/ash/actions/update.ex:38: Ash.Actions.Update.run/4
(app 0.1.3) lib/app/api.ex:1: App.Api.update/2
(app 0.1.3) lib/app/resources/auth/session.ex:83: App.Session.manual_0_generated_247EFA27A05C93763A80C351587532F0/2
(ash 2.6.31) lib/ash/actions/create.ex:354: anonymous fn/8 in Ash.Actions.Create.as_requests/5
(ash 2.6.31) lib/ash/changeset/changeset.ex:1865: Ash.Changeset.run_around_actions/2
(ash 2.6.31) lib/ash/changeset/changeset.ex:1575: anonymous fn/2 in Ash.Changeset.with_hooks/3
(ecto_sql 3.10.1) lib/ecto/adapters/sql.ex:1203: anonymous fn/3 in Ecto.Adapters.SQL.checkout_or_transaction/4
(db_connection 2.5.0) lib/db_connection.ex:1630: DBConnection.run_transaction/4
(ash 2.6.31) lib/ash/changeset/changeset.ex:1573: anonymous fn/3 in Ash.Changeset.with_hooks/3
(ash 2.6.31) lib/ash/changeset/changeset.ex:1689: Ash.Changeset.transaction_hooks/2
(ash 2.6.31) lib/ash/actions/create.ex:319: anonymous fn/10 in Ash.Actions.Create.as_requests/5
(ash 2.6.31) lib/ash/engine/request.ex:1048: Ash.Engine.Request.do_try_resolve_local/4
(ash 2.6.31) lib/ash/engine/request.ex:282: Ash.Engine.Request.do_next/1
(ash 2.6.31) lib/ash/engine/request.ex:211: Ash.Engine.Request.next/1
(ash 2.6.31) lib/ash/engine/engine.ex:683: Ash.Engine.advance_request/2
(ash 2.6.31) lib/ash/engine/engine.ex:589: Ash.Engine.fully_advance_request/2
(ash 2.6.31) lib/ash/engine/engine.ex:530: Ash.Engine.do_run_iteration/2

(elixir 1.14.4) lib/process.ex:773: Process.info/2
(ash 2.6.31) lib/ash/actions/helpers.ex:220: Ash.Actions.Helpers.warn_missed!/3
(ash 2.6.31) lib/ash/actions/update.ex:175: Ash.Actions.Update.add_notifications/6
(ash 2.6.31) lib/ash/actions/update.ex:38: Ash.Actions.Update.run/4
(app 0.1.3) lib/app/api.ex:1: App.Api.update/2
(app 0.1.3) lib/app/resources/auth/session.ex:83: App.Session.manual_0_generated_247EFA27A05C93763A80C351587532F0/2
(ash 2.6.31) lib/ash/actions/create.ex:354: anonymous fn/8 in Ash.Actions.Create.as_requests/5
(ash 2.6.31) lib/ash/changeset/changeset.ex:1865: Ash.Changeset.run_around_actions/2
(ash 2.6.31) lib/ash/changeset/changeset.ex:1575: anonymous fn/2 in Ash.Changeset.with_hooks/3
(ecto_sql 3.10.1) lib/ecto/adapters/sql.ex:1203: anonymous fn/3 in Ecto.Adapters.SQL.checkout_or_transaction/4
(db_connection 2.5.0) lib/db_connection.ex:1630: DBConnection.run_transaction/4
(ash 2.6.31) lib/ash/changeset/changeset.ex:1573: anonymous fn/3 in Ash.Changeset.with_hooks/3
(ash 2.6.31) lib/ash/changeset/changeset.ex:1689: Ash.Changeset.transaction_hooks/2
(ash 2.6.31) lib/ash/actions/create.ex:319: anonymous fn/10 in Ash.Actions.Create.as_requests/5
(ash 2.6.31) lib/ash/engine/request.ex:1048: Ash.Engine.Request.do_try_resolve_local/4
(ash 2.6.31) lib/ash/engine/request.ex:282: Ash.Engine.Request.do_next/1
(ash 2.6.31) lib/ash/engine/request.ex:211: Ash.Engine.Request.next/1
(ash 2.6.31) lib/ash/engine/engine.ex:683: Ash.Engine.advance_request/2
(ash 2.6.31) lib/ash/engine/engine.ex:589: Ash.Engine.fully_advance_request/2
(ash 2.6.31) lib/ash/engine/engine.ex:530: Ash.Engine.do_run_iteration/2

ZachDaniel•3y ago

I'll tell you hwat I'll just make it all unnecessary and make the internals gather up notifications magically 🙂

\ ឵឵឵OP•3y ago

Works for me 😁 Thanks mate

ZachDaniel•3y ago

can you try main? It should handle the notifications automatically now

\ ឵឵឵OP•3y ago

Yep, just a minute

ZachDaniel•3y ago

Don't forget to remove your code that does return_notifications?

\ ឵឵឵OP•3y ago

Already gone Now I'm getting the warning twice :thinkies: (for different actions, though)

ZachDaniel•3y ago

🤔 but you weren't getting it before for those actions?

\ ឵឵឵OP•3y ago

The second warning? Nope. But it looks like everything is working otherwise.

ZachDaniel•3y ago

Sorry, still a bit unclear. Did you used to get warnings from those actions at all? So was it 1 and now its 2? Or was it 0 and now its 2?

\ ឵឵឵OP•3y ago

I wasn't getting notification warnings lately, since I had them as

Resource
|> Changeset.for_action(...)

Resource
|> Changeset.for_action(...)

During the thread I've switched one path over to using code interface rather than that, but before it was producing only one warning. The two warnings it creates are for the actions I'd expect the path to take, though, so good possibility the one warning was worse.

ZachDaniel•3y ago

can you lay it all out? like what actions you're talking about, how you're invoking them? are you using return_notifications? anywhere?

\ ឵឵឵OP•3y ago

I had only added it to the one path as well, and removed it.

  def nested_ctx(ctx) do
    ctx
    |> Map.take([:authorize?, :actor, :context])
    |> Map.to_list
  end

  def nested_ctx(ctx) do
    ctx
    |> Map.take([:authorize?, :actor, :context])
    |> Map.to_list
  end

This is the util for threading context. The manual actions are returning from the code interface, like:

Post.create(%{...}, nested_ctx ctx)

Post.create(%{...}, nested_ctx ctx)

Error conditions are being returned so:

{:error, Ash.Error.to_ash_error("unable to create post")}

{:error, Ash.Error.to_ash_error("unable to create post")}

The vast majority of the actions are still create, update, etc. and not manual as we spoke about above. (where possible)

ZachDaniel•3y ago

I just pushed up another thing to main mix deps.update ash try updating it and see if that helps

\ ឵឵឵OP•3y ago

Sure, 2 new commits?

ZachDaniel•3y ago

yep

\ ឵឵឵OP•3y ago

Same 2 The new warning is coming from this action:

manual fn cs, _ ->
  a = Changeset.get_argument(cs, :a)
  b = Changeset.get_attribute(cs, :b)
  valid = verify_attributes(a, b)
  case valid do
    true -> Changeset.apply_attributes(cs)
    false -> {:error, Ash.Error.to_error_class("unable to verify attributes", changeset: cs)}
  end
end

manual fn cs, _ ->
  a = Changeset.get_argument(cs, :a)
  b = Changeset.get_attribute(cs, :b)
  valid = verify_attributes(a, b)
  case valid do
    true -> Changeset.apply_attributes(cs)
    false -> {:error, Ash.Error.to_error_class("unable to verify attributes", changeset: cs)}
  end
end

(Which is called by the first action)

ZachDaniel•3y ago

that doesn't make any sense 😆 that action isn't even doing anything its just returning a struct can I see how the first action is calling it?

\ ឵឵឵OP•3y ago

Just a sec

ZachDaniel•3y ago

I have an example in my tests that does the same thing essentially (calls a nested action from within an action) and its not showing that warning

\ ឵឵឵OP•3y ago

with {:tag, {:ok, %Tag{category: %Category{} = category}}} <-
        {:a, Tag.get([tag: tag], authorize?: false, load: [:category])},
      {:cat, {:ok, %Category{parent: %Parent{} = parent}}} <-
        {:b, Category.proxy(category, parent, authorize?: false)}
do
  Post.create(%{}, nested_ctx ctx)
else
  {:tag, _} ->
    {:error, Ash.Error.to_ash_error("invalid tag")}

  {:cat, _} ->
    {:error, Ash.Error.to_ash_error("invalid category")}
end

with {:tag, {:ok, %Tag{category: %Category{} = category}}} <-
        {:a, Tag.get([tag: tag], authorize?: false, load: [:category])},
      {:cat, {:ok, %Category{parent: %Parent{} = parent}}} <-
        {:b, Category.proxy(category, parent, authorize?: false)}
do
  Post.create(%{}, nested_ctx ctx)
else
  {:tag, _} ->
    {:error, Ash.Error.to_ash_error("invalid tag")}

  {:cat, _} ->
    {:error, Ash.Error.to_ash_error("invalid category")}
end

That's the shape of it. The get is unsurprisingly fine, the action call issuing a warning is the second action in the with. This action is being called via code interface, and warnings are coming from both Post.create and Category.proxy. This action is not generating a warning Gonna try something No dice

ZachDaniel•3y ago

Are you creating a transaction manually above that? like Repo.transaction?

\ ឵឵឵OP•3y ago

Nope, just calling that last action via code interface.

ZachDaniel•3y ago

And the warning points at that Post.create I'll have to take a look later then

\ ឵឵឵OP•3y ago

Yep, Post.create and Category.proxy No worries 🙂

ZachDaniel•3y ago

Found the problem 🙂 will fix it later tonight or tomorrow 🙂 Fixed in main 🙂

Gaming

Programming

Proxying actions to other actions

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