Ash Elixir•3y ago

Auto generate a slug

I have the following attributes and would like to autogenerate a slug from the name. Until now I always used https://github.com/wemake-services/ecto_autoslug_field to do this. What is the ash way to solve this?

attributes do  
  uuid_primary_key :id
  attribute :name, :string
  attribute :slug, :string
end

GitHub

GitHub - wemake-services/ecto_autoslug_field: Automatically create ...

Automatically create slugs for Ecto schemas. Contribute to wemake-services/ecto_autoslug_field development by creating an account on GitHub.

3 Replies

ZachDaniel•3y ago

What you'd want to do is add a "global change", which is done using the top level changes DSL. You'd want to do something like this.

changes do
  change fn changeset, _ -> 
    if Ash.Changeset.changing_attribute?(changeset, :field) do
      value = Ash.Changeset.get_attribute(changeset, :slug, :field)
      Ash.Changeset.force_change_attribute(changeset, make_slug(value))
    else
      changeset
    end
  end
end

changes do
  change fn changeset, _ -> 
    if Ash.Changeset.changing_attribute?(changeset, :field) do
      value = Ash.Changeset.get_attribute(changeset, :slug, :field)
      Ash.Changeset.force_change_attribute(changeset, make_slug(value))
    else
      changeset
    end
  end
end

And if you want to make it reusable, define your change in a module, and provide opts like so:

defmodule MakeSlug do
  use Ash.Resource.Change

  def changeset(changeset, opts, _context) do
    field = opts[:fields]
    slug = opts[:slug]
    if Ash.Changeset.changing_attribute?(changeset, field) do
      value = Ash.Changeset.get_attribute(changeset, field)
      Ash.Changeset.force_change_attribute(changeset, slug, make_slug(value))
    else
      changeset
    end
  end
end

defmodule MakeSlug do
  use Ash.Resource.Change

  def changeset(changeset, opts, _context) do
    field = opts[:fields]
    slug = opts[:slug]
    if Ash.Changeset.changing_attribute?(changeset, field) do
      value = Ash.Changeset.get_attribute(changeset, field)
      Ash.Changeset.force_change_attribute(changeset, slug, make_slug(value))
    else
      changeset
    end
  end
end

So then you can do change {MakeSlug, field: :field, slug: :slug}

Stefan WintermeyerOP•3y ago

Thanks!

ZachDaniel•3y ago

If your question/issue has been resolved, please close the forum post and add the "resolved" tag. Thanks for using the new forum system, hopefully this was and continues to be a good experience 🙂

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Auto generate a slug

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