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57 lines
1.8 KiB
Markdown
57 lines
1.8 KiB
Markdown
# Use Enums with GraphQL
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If you define an `Ash.Type.Enum`, that enum type can be used both in attributes _and_ arguments. You will need to add `graphql_type/0` to your implementation. AshGraphql will ensure that a single type is defined for it, which will be reused across all occurrences. If an enum
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type is referenced, but does not have `graphql_type/0` defined, it will
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be treated as a string input.
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For example:
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```elixir
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defmodule AshPostgres.Test.Types.Status do
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@moduledoc false
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use Ash.Type.Enum, values: [:open, :closed]
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def graphql_type, do: :ticket_status
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# Optionally, remap the names used in GraphQL, for instance if you have a value like `:"10"`
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# that value is not compatible with GraphQL
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def graphql_rename_value(:"10"), do: :ten
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def graphql_rename_value(value), do: value
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# You can also provide descriptions for the enum values, which will be exposed in the GraphQL
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# schema.
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# Remember to have a fallback clause that returns nil if you don't provide descriptions for all
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# values.
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def graphql_describe_enum_value(:open), do: "The post is open"
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def graphql_describe_enum_value(_), do: nil
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end
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```
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### Using custom absinthe types
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You can implement a custom enum by first adding the enum type to your absinthe schema (more [here](https://hexdocs.pm/absinthe/Absinthe.Type.Enum.html)). Then you can define a custom Ash type that refers to that absinthe enum type.
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```elixir
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# In your absinthe schema:
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enum :status do
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value(:open, description: "The post is open")
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value(:closed, description: "The post is closed")
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end
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```
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```elixir
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# Your custom Ash Type
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defmodule AshGraphql.Test.Status do
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use Ash.Type.Enum, values: [:open, :closed]
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use AshGraphql.Type
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@impl true
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# tell Ash not to define the type for that enum
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def graphql_define_type?(_), do: false
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end
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```
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