Ash Elixir•3y ago

If I set an argument default in a Flow I have it `nil` in a custom step

defmodule MmsBiztalk.Flows.Rollback do
  use Ash.Flow

  flow do
    api MmsBiztalk

    argument :resource, :string do
      allow_nil? false
    end

    argument :step, :integer do
      default 1
    end

    argument :resource_id, :integer

    returns :get_last_data_in_resources
  end

  steps do
    custom :get_last_data_in_resources, MmsBiztalk.Flows.Steps.LastDataInResources do
      input %{resource: arg(:resource), resource_id: arg(:resource_id)}
    end

    transaction :back_in_time, MmsBiztalk.DataIn do
      map :cycle_resources_changes, result(:get_last_data_in_resources) do
        custom :rollback_resource, MmsBiztalk.Flows.Steps.RollbackResource do
          input %{
            resource: arg(:resource),
            change: element(:cycle_resources_changes),
            step: arg(:step)
          }
        end
      end
    end
  end
end

defmodule MmsBiztalk.Flows.Rollback do
  use Ash.Flow

  flow do
    api MmsBiztalk

    argument :resource, :string do
      allow_nil? false
    end

    argument :step, :integer do
      default 1
    end

    argument :resource_id, :integer

    returns :get_last_data_in_resources
  end

  steps do
    custom :get_last_data_in_resources, MmsBiztalk.Flows.Steps.LastDataInResources do
      input %{resource: arg(:resource), resource_id: arg(:resource_id)}
    end

    transaction :back_in_time, MmsBiztalk.DataIn do
      map :cycle_resources_changes, result(:get_last_data_in_resources) do
        custom :rollback_resource, MmsBiztalk.Flows.Steps.RollbackResource do
          input %{
            resource: arg(:resource),
            change: element(:cycle_resources_changes),
            step: arg(:step)
          }
        end
      end
    end
  end
end

in MmsBiztalk.Flows.Steps.RollbackResource the value of input.step is nil.

13 Replies

ZachDaniel•3y ago

So it’s not setting default values?

tommasop#2001OP•3y ago

Exactly

ZachDaniel•3y ago

fixed in main 🙂

tommasop#2001OP•3y ago

Working thanks a lot @Zach Daniel it now seems if I set the value it will still get the default .... 😅

ZachDaniel•3y ago

Wait really? Does it happen only if you set the value to nil?

tommasop#2001OP•3y ago

the actual case is with the default value to nil?

ZachDaniel•3y ago

sorry, not following

tommasop#2001OP•3y ago

    argument :update_key, :atom do
      default nil
    end

    argument :status_changes, :term do
      default nil
    end

    returns :create_data_in_and_map_resources
  end

  steps do
    transaction :create_data_in_and_map_resources, MmsBiztalk.DataIn do
      create :create_data_in, MmsBiztalk.DataIn, :create do
        input %{data_type: arg(:data_type)}
      end

      map :cycle_resources, arg(:resources_attributes) do
        branch :creation_bulk, expr(is_nil(^arg(:update_key))) do
          custom :create_resource, MmsBiztalk.Flows.Steps.CreateResource do
            input %{
              attributes: element(:cycle_resources),
              resource: arg(:resource),
              data_in_id: path(result(:create_data_in), [:id])
            }
          end

    argument :update_key, :atom do
      default nil
    end

    argument :status_changes, :term do
      default nil
    end

    returns :create_data_in_and_map_resources
  end

  steps do
    transaction :create_data_in_and_map_resources, MmsBiztalk.DataIn do
      create :create_data_in, MmsBiztalk.DataIn, :create do
        input %{data_type: arg(:data_type)}
      end

      map :cycle_resources, arg(:resources_attributes) do
        branch :creation_bulk, expr(is_nil(^arg(:update_key))) do
          custom :create_resource, MmsBiztalk.Flows.Steps.CreateResource do
            input %{
              attributes: element(:cycle_resources),
              resource: arg(:resource),
              data_in_id: path(result(:create_data_in), [:id])
            }
          end

the argument update_key even if has a value is always nil

ZachDaniel•3y ago

🥲

ZachDaniel•3y ago

I don’t really see how that would happen here: https://github.com/ash-project/ash/blob/main/lib/ash/flow/flow.ex#L168

GitHub

ash/flow.ex at main · ash-project/ash

A declarative and extensible framework for building Elixir applications. - ash/flow.ex at main · ash-project/ash

tommasop#2001OP•3y ago

tommasop#2001OP•3y ago

Sorry my bad, the problem is how to pass parameters to flows it seems after some number of parameters the arguments must go in a map I can pass parameters normally up to three (don't know why)

MmsBiztalk.Flows.EsolverToBiztalk.BulkPull.run("one", "two", "three")

MmsBiztalk.Flows.EsolverToBiztalk.BulkPull.run("one", "two", "three")

after the third I need to pass them in maps:

MmsBiztalk.Flows.EsolverToBiztalk.BulkPull.run("one", "two", "three", %{four: "four", five: "five"})

MmsBiztalk.Flows.EsolverToBiztalk.BulkPull.run("one", "two", "three", %{four: "four", five: "five"})

ZachDaniel•3y ago

ah, its only params that don't have defaults that are automatically added as arguments Sorry, it’s “params that are required that don’t have a default” it’s a bit magical, probably should have just made them all passed as a map TBH

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If I set an argument default in a Flow I have it `nil` in a custom step

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