Ash Framework•3mo ago

How do I use a schema macro in an extension?

I want to make an Ash extension that adds a :uuid_v7_primary_key attribute to a resource. Adding an attribute via a macro: This is an antipattern but it’s a small example. The macro definition (Geo.Resources.Attributes.Id): https://github.com/dev-guy/geo/blob/e6aaf95d63961b4e40df6f51ac382393840c010a/lib/geo/resources/attributes/id.ex Using it: https://github.com/dev-guy/geo/blob/70baa42f3ea8a5b092345e478f61a552fb79d9fb/lib/geo/country/country.ex Adding an attribute via an extension: Macros are great but they are not Ashy. As with the macro, can I reuse uuid_v7_primary_key in an extension? Claude tried and got syntax errors (below) The extension definition: https://github.com/dev-guy/geo/blob/e6aaf95d63961b4e40df6f51ac382393840c010a/lib/geo/resources/extensions/id.ex Using it: https://github.com/dev-guy/geo/blob/e6aaf95d63961b4e40df6f51ac382393840c010a/lib/geo/geography/country.ex Do I have to essentially reimplement :uuid_v7_primary_key? Error:

== Compilation error in file lib/geo/geography/country.ex ==
** (RuntimeError) Exception in transformer Geo.Resources.Extensions.Id.Transformer on Geo.Geography.Country: 

no function clause matching in anonymous fn/2 in Keyword.split/2
    (elixir 1.18.4) lib/keyword.ex:1213: anonymous fn(:id, {[], []}) in Keyword.split/2
    (elixir 1.18.4) lib/keyword.ex:1221: Keyword."-split/2-lists^foldl/2-1-"/3
    (elixir 1.18.4) lib/keyword.ex:1221: Keyword.split/2
    (spark 2.2.67) lib/spark/dsl/transformer.ex:177: Spark.Dsl.Transformer.do_build/2
    lib/geo/resources/extensions/id.ex:19: Geo.Resources.Extensions.Id.Transformer.transform/1
    (spark 2.2.67) lib/spark/dsl/extension.ex:661: anonymous fn/4 in Spark.Dsl.Extension.run_transformers/4
    (elixir 1.18.4) lib/enum.ex:4968: Enumerable.List.reduce/3
    geo/lib/geo/geography/country.ex:1: (file)

== Compilation error in file lib/geo/geography/country.ex ==
** (RuntimeError) Exception in transformer Geo.Resources.Extensions.Id.Transformer on Geo.Geography.Country: 

no function clause matching in anonymous fn/2 in Keyword.split/2
    (elixir 1.18.4) lib/keyword.ex:1213: anonymous fn(:id, {[], []}) in Keyword.split/2
    (elixir 1.18.4) lib/keyword.ex:1221: Keyword."-split/2-lists^foldl/2-1-"/3
    (elixir 1.18.4) lib/keyword.ex:1221: Keyword.split/2
    (spark 2.2.67) lib/spark/dsl/transformer.ex:177: Spark.Dsl.Transformer.do_build/2
    lib/geo/resources/extensions/id.ex:19: Geo.Resources.Extensions.Id.Transformer.transform/1
    (spark 2.2.67) lib/spark/dsl/extension.ex:661: anonymous fn/4 in Spark.Dsl.Extension.run_transformers/4
    (elixir 1.18.4) lib/enum.ex:4968: Enumerable.List.reduce/3
    geo/lib/geo/geography/country.ex:1: (file)

Solution:

YOu can do Ash.Resource.Builder.add_new_attribute(dsl_state, ....)

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3 Replies

TerrisOP•3mo ago

I think I see where Claude messed up. It used uuid_v7_primary_key as an atom instead of using the macro. This extension works: https://github.com/dev-guy/geo/blob/702c58a366687f383381dc9b69fd58c35432f0ac/lib/geo/resources/attributes/id.ex but I was hoping to leverage the uuid_v7_primary_key schema. Excerpt:

def transform(dsl_state) do
      attribute = %Ash.Resource.Attribute{
        name: :id,
        type: :uuid_v7,
        allow_nil?: false,
        writable?: false,
        public?: true,
        primary_key?: true,
        default: &Ash.UUIDv7.generate/0
      }

def transform(dsl_state) do
      attribute = %Ash.Resource.Attribute{
        name: :id,
        type: :uuid_v7,
        allow_nil?: false,
        writable?: false,
        public?: true,
        primary_key?: true,
        default: &Ash.UUIDv7.generate/0
      }

Solution

ZachDaniel•3mo ago

YOu can do Ash.Resource.Builder.add_new_attribute(dsl_state, ....)

ZachDaniel•3mo ago

or in your case if you just want to build it then Ash.Resource.Builder.build_attribute/3 nothing does the uuidv7 schema but you can copy build_attribute example to make your own for build_uuidv7_primary_key

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How do I use a schema macro in an extension?

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