AF
Ash Framework•3mo ago
Sirius

How to use one Enum value for REST/GraphQL, serialized as another to the database

Hello all, I'm still new to Elixir and the Ash framework. I'm trying to create a set of values to use for both the REST and GraphQL interfaces of my API to have values spelt out such as north, north_east, etc. spelt out. However when I read or write that field to the database, I'd like to have it serialized as string values such as N, NE, etc. Here's the code I have so far: 
defmodule My.Direction do
  use Ash.Type.Enum
    values: [
      :north,
      :north_east,
      :east,
      :south_east,
      :south,
      :south_west,
      :west,
      :north_west
    ]
      
  use AshGraphql.Type
  
  def storage_type(), do: :string
  
  @impl AshGraphql.Type
  def graphql_type(_), do: :direction
end


defmodule My.BoatPath do
  use Ash.Resource
  ...

  attributes do
    ...
    attribute :direction, My.Direction do
      allow_nil? true
      public? true
    end
    ...
  end
end
defmodule My.Direction do
  use Ash.Type.Enum
    values: [
      :north,
      :north_east,
      :east,
      :south_east,
      :south,
      :south_west,
      :west,
      :north_west
    ]
      
  use AshGraphql.Type
  
  def storage_type(), do: :string
  
  @impl AshGraphql.Type
  def graphql_type(_), do: :direction
end


defmodule My.BoatPath do
  use Ash.Resource
  ...

  attributes do
    ...
    attribute :direction, My.Direction do
      allow_nil? true
      public? true
    end
    ...
  end
end
I've tried things like overriding Ecto.type definitions for load/1, dump/1 but it keeps failing on me when I try to load an existing database record with a direction field value of NE: 
 ** (ArgumentError) cannot load `"NE"` as type #My.Direction.EctoType<[]> for field :direction in %My.BoatPath{... direction: nil, ..., __meta__: #Ecto.Schema.Metadata<:loaded, "BOAT_PATH">}
 ** (ArgumentError) cannot load `"NE"` as type #My.Direction.EctoType<[]> for field :direction in %My.BoatPath{... direction: nil, ..., __meta__: #Ecto.Schema.Metadata<:loaded, "BOAT_PATH">}
Solution:
You can override the cast_stored and dump_to_native callbacks on the type
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1 Reply
Solution
ZachDaniel
ZachDaniel•3mo ago
You can override the cast_stored and dump_to_native callbacks on the type

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