Stefan Wintermeyer Posts - Answer Overflow

Stefan Wintermeyer

•Created by Stefan Wintermeyer on 9/24/2023 in #support

add_tag but unique

A product has a many_to_many relationship to a tag (via a product_tag resource).
lib/app/shop/resources/product.ex

    [...]
    create :create do
      primary? true
      argument :tags, {:array, :map}

      argument :add_tag, :map do
        allow_nil? false
      end

      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
      change manage_relationship(:add_tag, :tags, type: :create)
    end
    [...]

    [...]
    create :create do
      primary? true
      argument :tags, {:array, :map}

      argument :add_tag, :map do
        allow_nil? false
      end

      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
      change manage_relationship(:add_tag, :tags, type: :create)
    end
    [...]

This works nicely:

iex(6)> banana = App.Shop.Product.create!(%{name: "Banana", add_tag: %{name: "Yellow"}})

iex(6)> banana = App.Shop.Product.create!(%{name: "Banana", add_tag: %{name: "Yellow"}})

Unfortunately I can also add another "Yellow" tag via an update:

iex(7)> App.Shop.Product.update!(banana, %{add_tag: %{name: "Yellow"}}).tags |> Enum.map(& &1.name)
["Yellow", "Yellow"]

iex(7)> App.Shop.Product.update!(banana, %{add_tag: %{name: "Yellow"}}).tags |> Enum.map(& &1.name)
["Yellow", "Yellow"]

Obviously this should not happen. The "Yellow" tag should be unique. The longer I think about this the lesser I know how to solve it. Should I through a validation error? How can I do this? Should I just OK it but not adding another tag? How would I do that?

14 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/24/2023 in #support

How to add_tag? Managing Relationships

I try to adapt https://ash-hq.org/docs/guides/ash/latest/topics/managing-relationships for an application where a product which has a many_to_many relationship to tags. lib/app/shop/resources/product.ex

defmodule App.Shop.Product do
  [...]
  relationships do
    many_to_many :tags, App.Shop.Tag do
      through App.Shop.ProductTag
      source_attribute_on_join_resource :product_id
      destination_attribute_on_join_resource :tag_id
    end
  end

  actions do
    defaults [:read]

    create :create do
      primary? true
      argument :tags, {:array, :map}

      argument :add_tag, :map do
        allow_nil? false
      end

      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
      change manage_relationship(:add_tag, :tags, type: :create)
    end

    update :update do
      primary? true
      argument :tags, {:array, :map}

      argument :add_tag, :map do
        allow_nil? false
      end

      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
      change manage_relationship(:add_tag, :tags, type: :create)
    end
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
    define :update
  end
end

defmodule App.Shop.Product do
  [...]
  relationships do
    many_to_many :tags, App.Shop.Tag do
      through App.Shop.ProductTag
      source_attribute_on_join_resource :product_id
      destination_attribute_on_join_resource :tag_id
    end
  end

  actions do
    defaults [:read]

    create :create do
      primary? true
      argument :tags, {:array, :map}

      argument :add_tag, :map do
        allow_nil? false
      end

      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
      change manage_relationship(:add_tag, :tags, type: :create)
    end

    update :update do
      primary? true
      argument :tags, {:array, :map}

      argument :add_tag, :map do
        allow_nil? false
      end

      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
      change manage_relationship(:add_tag, :tags, type: :create)
    end
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
    define :update
  end
end

I get this error:

iex(1)> App.Shop.Product.create!(%{name: "Banana"}, add_tag: %{name: "Yellow"})
** (Ash.Error.Unknown) Unknown Error

* %NimbleOptions.ValidationError{message: "unknown options [:add_tag], valid options are: [:upsert?, :upsert_identity, :upsert_fields, :internal?, :timeout, :tracer, :verbose?, :action, :authorize?, :stacktraces?, :tenant, :actor, :after_action, :return_notifications?, :notification_metadata]", key: [:add_tag], value: nil, keys_path: []}
    (ash 2.14.18) lib/ash/api/api.ex:2179: Ash.Api.unwrap_or_raise!/3

iex(1)> App.Shop.Product.create!(%{name: "Banana"}, add_tag: %{name: "Yellow"})
** (Ash.Error.Unknown) Unknown Error

* %NimbleOptions.ValidationError{message: "unknown options [:add_tag], valid options are: [:upsert?, :upsert_identity, :upsert_fields, :internal?, :timeout, :tracer, :verbose?, :action, :authorize?, :stacktraces?, :tenant, :actor, :after_action, :return_notifications?, :notification_metadata]", key: [:add_tag], value: nil, keys_path: []}
    (ash 2.14.18) lib/ash/api/api.ex:2179: Ash.Api.unwrap_or_raise!/3

How can I fix that?

6 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/23/2023 in #support

many_to_many update problem

I have a product which has many_to_many tags. Creating works. Updating doesn't. Here's the resource code: lib/app/shop/resources/product.ex

defmodule App.Shop.Product do
  use Ash.Resource, data_layer: Ash.DataLayer.Ets

  attributes do
    uuid_primary_key :id
    attribute :name, :string
    attribute :price, :decimal
  end

  relationships do
    many_to_many :tags, App.Shop.Tag do
      through App.Shop.ProductTag
      source_attribute_on_join_resource :product_id
      destination_attribute_on_join_resource :tag_id
    end
  end

  actions do
    defaults [:read, :destroy]

    create :create do
      primary? true
      argument :tags, {:array, :map}
      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
    end

    create :update do
      argument :tags, {:array, :map}
      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
    end
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
    define :by_name, get_by: [:name], action: :read
    define :update
    define :destroy
  end
end

defmodule App.Shop.Product do
  use Ash.Resource, data_layer: Ash.DataLayer.Ets

  attributes do
    uuid_primary_key :id
    attribute :name, :string
    attribute :price, :decimal
  end

  relationships do
    many_to_many :tags, App.Shop.Tag do
      through App.Shop.ProductTag
      source_attribute_on_join_resource :product_id
      destination_attribute_on_join_resource :tag_id
    end
  end

  actions do
    defaults [:read, :destroy]

    create :create do
      primary? true
      argument :tags, {:array, :map}
      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
    end

    create :update do
      argument :tags, {:array, :map}
      change manage_relationship(:tags, type: :append_and_remove, on_no_match: :create)
    end
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
    define :by_name, get_by: [:name], action: :read
    define :update
    define :destroy
  end
end

Here's what I do in the iex:

iex(1)> good_deal_tag = App.Shop.Tag.create!(%{name: "Good deal"})
iex(2)> yellow_tag = App.Shop.Tag.create!(%{name: "Yellow"})
iex(3)> App.Shop.Product.create!(%{
            name: "Banana",
            tags: [good_deal_tag, yellow_tag]
            })
iex(4) banana = App.Shop.Product.by_name!("Banana", load: [:tags])

iex(1)> good_deal_tag = App.Shop.Tag.create!(%{name: "Good deal"})
iex(2)> yellow_tag = App.Shop.Tag.create!(%{name: "Yellow"})
iex(3)> App.Shop.Product.create!(%{
            name: "Banana",
            tags: [good_deal_tag, yellow_tag]
            })
iex(4) banana = App.Shop.Product.by_name!("Banana", load: [:tags])

That all works nicely. But I can not update the products tags or the even the product:

iex(16)> App.Shop.Product.update!(banana, %{tags: [yellow_tag]})
** (FunctionClauseError) no function clause matching in Keyword.split/2
[...]
iex(16)> App.Shop.Product.update!(banana, %{name: "test"})
** (FunctionClauseError) no function clause matching in Keyword.split/2

iex(16)> App.Shop.Product.update!(banana, %{tags: [yellow_tag]})
** (FunctionClauseError) no function clause matching in Keyword.split/2
[...]
iex(16)> App.Shop.Product.update!(banana, %{name: "test"})
** (FunctionClauseError) no function clause matching in Keyword.split/2

How can I fix this?

13 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/22/2023 in #showcase

Tutorial: has_many in 2m 19s

https://www.youtube.com/watch?v=jQZGHl4B4fU Source code and other tutorials at https://elixir-phoenix-ash.com/ash/relationships.html#ash-has_many

1 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/21/2023 in #showcase

Tutorial: belongs_to in 2 minutes

I uploaded a video tutorial how to configure and use belongs_to. https://www.youtube.com/watch?v=lP8YtkXD3RE

4 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/20/2023 in #support

How to create a product with many_to_many tags?

Setup:

defmodule App.Shop.Product do
  [...]
  relationships do
    many_to_many :tags, App.Shop.Tag do
      through App.Shop.ProductTag
      source_attribute_on_join_resource :product_id
      destination_attribute_on_join_resource :tag_id
    end
  end

  actions do
    defaults [:create, :read]
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
    define :by_name, get_by: [:name], action: :read
  end
end

defmodule App.Shop.Product do
  [...]
  relationships do
    many_to_many :tags, App.Shop.Tag do
      through App.Shop.ProductTag
      source_attribute_on_join_resource :product_id
      destination_attribute_on_join_resource :tag_id
    end
  end

  actions do
    defaults [:create, :read]
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
    define :by_name, get_by: [:name], action: :read
  end
end

defmodule App.Shop.Tag do
  [...]

  relationships do
    many_to_many :products, App.Shop.Product do
      through App.Shop.ProductTag
      source_attribute_on_join_resource :tag_id
      destination_attribute_on_join_resource :product_id
    end
  end

  actions do
    defaults [:create, :read]
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
    define :by_name, get_by: [:name], action: :read
  end
end

defmodule App.Shop.Tag do
  [...]

  relationships do
    many_to_many :products, App.Shop.Product do
      through App.Shop.ProductTag
      source_attribute_on_join_resource :tag_id
      destination_attribute_on_join_resource :product_id
    end
  end

  actions do
    defaults [:create, :read]
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
    define :by_name, get_by: [:name], action: :read
  end
end

defmodule App.Shop.ProductTag do
  use Ash.Resource, data_layer: Ash.DataLayer.Ets

  relationships do
    belongs_to :product, App.Shop.Product do
      primary_key? true
      allow_nil? false
    end

    belongs_to :tag, App.Shop.Tag do
      primary_key? true
      allow_nil? false
    end
  end
end

defmodule App.Shop.ProductTag do
  use Ash.Resource, data_layer: Ash.DataLayer.Ets

  relationships do
    belongs_to :product, App.Shop.Product do
      primary_key? true
      allow_nil? false
    end

    belongs_to :tag, App.Shop.Tag do
      primary_key? true
      allow_nil? false
    end
  end
end

The iex preparation:

iex(1)> good_deal_tag = App.Shop.Tag.create!(%{name: "Good deal"})
iex(2)> yellow_tag = App.Shop.Tag.create!(%{name: "Yellow"})

iex(1)> good_deal_tag = App.Shop.Tag.create!(%{name: "Good deal"})
iex(2)> yellow_tag = App.Shop.Tag.create!(%{name: "Yellow"})

Question: How can I create a new product which has the two tags good_deal_tag and yellow_tag? Something like:

iex(3) App.Shop.Product.create!(%{name: "Banana", tags: [good_deal_tag, yellow_tag]})

iex(3) App.Shop.Product.create!(%{name: "Banana", tags: [good_deal_tag, yellow_tag]})

18 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/20/2023 in #support

How to autoload a relationship?

The setup: lib/app/shop/resources/product.ex

defmodule App.Shop.Product do
  [...]
  relationships do
    belongs_to :category, App.Shop.Category do
      attribute_writable? true
    end
  end
  [...]
end

defmodule App.Shop.Product do
  [...]
  relationships do
    belongs_to :category, App.Shop.Category do
      attribute_writable? true
    end
  end
  [...]
end

I want to query for the product "Banana":

iex(12)> fruits = App.Shop.Category.create!(%{name: "Fruits"})
#App.Shop.Category<
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
  name: "Fruits",
  ...
>
iex(13)> banana = App.Shop.Product.create!(%{name: "Banana", price: 0.1, category_id: fruits.id})
#App.Shop.Product<
  promotion: #Ash.NotLoaded<:relationship>,
  category: #Ash.NotLoaded<:relationship>,
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "d655fa01-ece5-4ad9-b927-764a6a48b165",
  name: "Banana",
  price: Decimal.new("0.1"),
  category_id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
  ...
>
iex(14)> App.Shop.Product.by_name("Banana")
{:ok,
 #App.Shop.Product<
   promotion: #Ash.NotLoaded<:relationship>,
   category: #Ash.NotLoaded<:relationship>,
   __meta__: #Ecto.Schema.Metadata<:loaded>,
   id: "d655fa01-ece5-4ad9-b927-764a6a48b165",
   name: "Banana",
   price: Decimal.new("0.1"),
   category_id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
   ...
 >}
iex(15)> App.Shop.load(banana, :category)
{:ok,
 #App.Shop.Product<
   promotion: #Ash.NotLoaded<:relationship>,
   category: #App.Shop.Category<
     __meta__: #Ecto.Schema.Metadata<:loaded>,
     id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
     name: "Fruits",
     ...
   >,
   __meta__: #Ecto.Schema.Metadata<:loaded>,
   id: "d655fa01-ece5-4ad9-b927-764a6a48b165",
   name: "Banana",
   price: Decimal.new("0.1"),
   category_id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
   ...
 >}

iex(12)> fruits = App.Shop.Category.create!(%{name: "Fruits"})
#App.Shop.Category<
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
  name: "Fruits",
  ...
>
iex(13)> banana = App.Shop.Product.create!(%{name: "Banana", price: 0.1, category_id: fruits.id})
#App.Shop.Product<
  promotion: #Ash.NotLoaded<:relationship>,
  category: #Ash.NotLoaded<:relationship>,
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "d655fa01-ece5-4ad9-b927-764a6a48b165",
  name: "Banana",
  price: Decimal.new("0.1"),
  category_id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
  ...
>
iex(14)> App.Shop.Product.by_name("Banana")
{:ok,
 #App.Shop.Product<
   promotion: #Ash.NotLoaded<:relationship>,
   category: #Ash.NotLoaded<:relationship>,
   __meta__: #Ecto.Schema.Metadata<:loaded>,
   id: "d655fa01-ece5-4ad9-b927-764a6a48b165",
   name: "Banana",
   price: Decimal.new("0.1"),
   category_id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
   ...
 >}
iex(15)> App.Shop.load(banana, :category)
{:ok,
 #App.Shop.Product<
   promotion: #Ash.NotLoaded<:relationship>,
   category: #App.Shop.Category<
     __meta__: #Ecto.Schema.Metadata<:loaded>,
     id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
     name: "Fruits",
     ...
   >,
   __meta__: #Ecto.Schema.Metadata<:loaded>,
   id: "d655fa01-ece5-4ad9-b927-764a6a48b165",
   name: "Banana",
   price: Decimal.new("0.1"),
   category_id: "3a3ed806-6df4-4602-aff6-4eed50e814b2",
   ...
 >}

Question: How can I autoload the category when I query for a product so that I don't have to do two SQL requests? App.Shop.Product.by_name("Banana") should get me the product and the category.

5 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/20/2023 in #support

How to create a product with a category id?

The setup: lib/app/shop/resources/category.ex

defmodule App.Shop.Category do
  use Ash.Resource, data_layer: Ash.DataLayer.Ets

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

  actions do
    defaults [:create, :read]
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
  end
end

defmodule App.Shop.Category do
  use Ash.Resource, data_layer: Ash.DataLayer.Ets

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

  actions do
    defaults [:create, :read]
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
  end
end

lib/app/shop/resources/product.ex

defmodule App.Shop.Product do
  use Ash.Resource, data_layer: Ash.DataLayer.Ets

  attributes do
    uuid_primary_key :id
    attribute :name, :string
    attribute :price, :decimal
  end

  relationships do
    belongs_to :category, App.Shop.Category
  end

  actions do
    defaults [:create, :read]
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
  end
end

defmodule App.Shop.Product do
  use Ash.Resource, data_layer: Ash.DataLayer.Ets

  attributes do
    uuid_primary_key :id
    attribute :name, :string
    attribute :price, :decimal
  end

  relationships do
    belongs_to :category, App.Shop.Category
  end

  actions do
    defaults [:create, :read]
  end

  code_interface do
    define_for App.Shop
    define :create
    define :read
  end
end

Question: How can I create a new Product which includes a Category? This is what I tried:

iex(1)> fruits = App.Shop.Category.create!(%{name: "Fruits"})
#App.Shop.Category<
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "5b582e8a-3c19-4ce4-b609-88748a46e2ce",
  name: "Fruits",
  aggregates: %{},
  calculations: %{},
  ...
>
iex(3)> orange = App.Shop.Product.create!(%{name: "Orange", price: 0.20, category: fruits})
#App.Shop.Product<
  category: #Ash.NotLoaded<:relationship>,
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "432152d7-715d-4731-8fe4-ed90b05ee30e",
  name: "Orange",
  price: Decimal.new("0.2"),
  category_id: nil,
  aggregates: %{},
  calculations: %{},
  ...
>
iex(4)> orange = App.Shop.Product.create!(%{name: "Orange", price: 0.20, category_id: fruits.id})
#App.Shop.Product<
  category: #Ash.NotLoaded<:relationship>,
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "68c1023e-5b57-4819-a4a2-ff16f7efdc5d",
  name: "Orange",
  price: Decimal.new("0.2"),
  category_id: nil,
  aggregates: %{},
  calculations: %{},
  ...
>
iex(5)>

iex(1)> fruits = App.Shop.Category.create!(%{name: "Fruits"})
#App.Shop.Category<
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "5b582e8a-3c19-4ce4-b609-88748a46e2ce",
  name: "Fruits",
  aggregates: %{},
  calculations: %{},
  ...
>
iex(3)> orange = App.Shop.Product.create!(%{name: "Orange", price: 0.20, category: fruits})
#App.Shop.Product<
  category: #Ash.NotLoaded<:relationship>,
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "432152d7-715d-4731-8fe4-ed90b05ee30e",
  name: "Orange",
  price: Decimal.new("0.2"),
  category_id: nil,
  aggregates: %{},
  calculations: %{},
  ...
>
iex(4)> orange = App.Shop.Product.create!(%{name: "Orange", price: 0.20, category_id: fruits.id})
#App.Shop.Product<
  category: #Ash.NotLoaded<:relationship>,
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: "68c1023e-5b57-4819-a4a2-ff16f7efdc5d",
  name: "Orange",
  price: Decimal.new("0.2"),
  category_id: nil,
  aggregates: %{},
  calculations: %{},
  ...
>
iex(5)>

The category_id is nil both times.

15 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/19/2023 in #showcase

Ash Resource - 3 minute introduction

Learn how to setup an Ash resource with create, read, update and destroy. https://www.youtube.com/watch?v=tYCL0Rk12no

3 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/14/2023 in #support

Validate not nil, min and max for a string

The following validation code doesn't work:

attributes do
  uuid_primary_key :id

  attribute :content, :string do
    allow_nil? false
    constraints: [min_length: 1, max_length: 255]
  end
end

attributes do
  uuid_primary_key :id

  attribute :content, :string do
    allow_nil? false
    constraints: [min_length: 1, max_length: 255]
  end
end

In the documentation I can only find examples for allow_nil? or constraints: [min_length: 1, max_length: 255] but none where both are combined. How do I have to change the code to work?

5 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 9/11/2023 in #support

Using code_interface args

When I use

code_interface do
  define_for Office.ToDoList
  define :create, args: [:subject]
end

code_interface do
  define_for Office.ToDoList
  define :create, args: [:subject]
end

I have access to Office.ToDoList.Task.create!("test") but not to Office.ToDoList.Task.create!(%{subject: "test2"}). For the later one to work I have to use define :create but then the first version doesn't work. Is there a way to have access to both versions or would that be a misuse of the code_interface concept?

13 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 2/13/2023 in #support

Many To Many Relationship Example

After reading https://www.ash-hq.org/docs/guides/ash/latest/topics/relationships.md#has-many and https://ash-hq.org/docs/dsl/ash/latest/ash-resource-dsl/relationships/many_to_many I am a little bit confused since the examples use different code. I am looking for a simple example which I can copy and paste. Something like a blog post which has multiple tags associated via a many to many relationship:

defmodule Example.Blog.Post do
  use Ash.Resource,
    data_layer: AshPostgres.DataLayer

  attributes do
    uuid_primary_key :id

    attribute :content, :string do
      allow_nil? false
    end
  end
  
  postgres do
    table "blog_posts"
    repo Example.Repo
  end
  
  actions do
    defaults [:create, :read]
  end
end

defmodule Example.Blog.Post do
  use Ash.Resource,
    data_layer: AshPostgres.DataLayer

  attributes do
    uuid_primary_key :id

    attribute :content, :string do
      allow_nil? false
    end
  end
  
  postgres do
    table "blog_posts"
    repo Example.Repo
  end
  
  actions do
    defaults [:create, :read]
  end
end

defmodule Example.Blog.Tag do
  use Ash.Resource,
    data_layer: AshPostgres.DataLayer

  attributes do
    uuid_primary_key :id

    attribute :name, :string do
      allow_nil? false
    end
  end
  
  postgres do
    table "tags"
    repo Example.Repo
  end
  
  actions do
    defaults [:create, :read]
  end
end

defmodule Example.Blog.Tag do
  use Ash.Resource,
    data_layer: AshPostgres.DataLayer

  attributes do
    uuid_primary_key :id

    attribute :name, :string do
      allow_nil? false
    end
  end
  
  postgres do
    table "tags"
    repo Example.Repo
  end
  
  actions do
    defaults [:create, :read]
  end
end

- What do I have to change in the existing files? - How do I have to do the third resource? - How would I add a tag to a blog post the Ash way?

5 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 2/12/2023 in #support

Can I fetch a resource with `get :id`?

To fetch a resource by a specific id I use this code:

[post] = MyApp.Post
|> Ash.Query.filter(id == "bc38fcb3-080d-46ba-834d-5as58d689sda")
|> Ash.Query.limit(1)
|> MyApp.Api.read!()

[post] = MyApp.Post
|> Ash.Query.filter(id == "bc38fcb3-080d-46ba-834d-5as58d689sda")
|> Ash.Query.limit(1)
|> MyApp.Api.read!()

Is there a shorter already build in way of fetching a single resource by it's id?

4 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 2/9/2023 in #support

Which type for Text?

How long can a Ash.Type.String become with AshPostgres.DataLayer? 255 characters? What type would I use for longer texts? I found this list but didn't find a text entry:

  :map -> Ash.Type.Map
  :term -> Ash.Type.Term
  :atom -> Ash.Type.Atom
  :string -> Ash.Type.String
  :integer -> Ash.Type.Integer
  :float -> Ash.Type.Float
  :duration_name -> Ash.Type.DurationName
  :function -> Ash.Type.Function
  :boolean -> Ash.Type.Boolean
  :struct -> Ash.Type.Struct
  :uuid -> Ash.Type.UUID
  :binary -> Ash.Type.Binary
  :date -> Ash.Type.Date
  :time -> Ash.Type.Time
  :decimal -> Ash.Type.Decimal
  :ci_string -> Ash.Type.CiString
  :naive_datetime -> Ash.Type.NaiveDatetime
  :utc_datetime -> Ash.Type.UtcDatetime
  :utc_datetime_usec -> Ash.Type.UtcDatetimeUsec
  :url_encoded_binary -> Ash.Type.UrlEncodedBinary

  :map -> Ash.Type.Map
  :term -> Ash.Type.Term
  :atom -> Ash.Type.Atom
  :string -> Ash.Type.String
  :integer -> Ash.Type.Integer
  :float -> Ash.Type.Float
  :duration_name -> Ash.Type.DurationName
  :function -> Ash.Type.Function
  :boolean -> Ash.Type.Boolean
  :struct -> Ash.Type.Struct
  :uuid -> Ash.Type.UUID
  :binary -> Ash.Type.Binary
  :date -> Ash.Type.Date
  :time -> Ash.Type.Time
  :decimal -> Ash.Type.Decimal
  :ci_string -> Ash.Type.CiString
  :naive_datetime -> Ash.Type.NaiveDatetime
  :utc_datetime -> Ash.Type.UtcDatetime
  :utc_datetime_usec -> Ash.Type.UtcDatetimeUsec
  :url_encoded_binary -> Ash.Type.UrlEncodedBinary

3 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 2/9/2023 in #support

Add Index to Attribute

I have this AshProstgres resource and would like to add an index to the link parameter. How can I do that?

  attributes do
    uuid_primary_key :id

    attribute :link, :string do
      allow_nil? false
    end
   end

  attributes do
    uuid_primary_key :id

    attribute :link, :string do
      allow_nil? false
    end
   end

2 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 2/9/2023 in #support

Create a Unique Attribute

I have this AshPostgres resource and want to make sure the the title is unique. How can I do that?

  attributes do
    uuid_primary_key :id

    attribute :title, :string do
      allow_nil? false
    end
  end

  attributes do
    uuid_primary_key :id

    attribute :title, :string do
      allow_nil? false
    end
  end

5 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 1/29/2023 in #support

Use secret_key_base as token_signing_secret

I have the following code in lib/example/accounts/user.ex:

tokens do
  enabled? true
  token_resource Example.Accounts.Token
  signing_secret fn _, _ ->
    System.fetch_env("TOKEN_SIGNING_SECRET")
  end
end

tokens do
  enabled? true
  token_resource Example.Accounts.Token
  signing_secret fn _, _ ->
    System.fetch_env("TOKEN_SIGNING_SECRET")
  end
end

Is there a way to use the secret_key_base which is already set in the Phoenix Application config instead of System.fetch_env("TOKEN_SIGNING_SECRET")?

7 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 1/29/2023 in #support

type "citext" does not exist

During the "Integrating Ash Authentication and Phoenix" tutorial I get this migration:

create table(:users, primary_key: false) do
  add :id, :uuid, null: false, primary_key: true
  add :email, :citext, null: false
  #           ^^^^^^^
  add :hashed_password, :text, null: false
end

create table(:users, primary_key: false) do
  add :id, :uuid, null: false, primary_key: true
  add :email, :citext, null: false
  #           ^^^^^^^
  add :hashed_password, :text, null: false
end

That results in the following error:

12:42:19.145 [info] create table users
** (Postgrex.Error) ERROR 42704 (undefined_object) type "citext" does not exist
    (ecto_sql 3.9.2) lib/ecto/adapters/sql.ex:913: Ecto.Adapters.SQL.raise_sql_call_error/1

12:42:19.145 [info] create table users
** (Postgrex.Error) ERROR 42704 (undefined_object) type "citext" does not exist
    (ecto_sql 3.9.2) lib/ecto/adapters/sql.ex:913: Ecto.Adapters.SQL.raise_sql_call_error/1

https://hexdocs.pm/ash_postgres/AshPostgres.Repo.html says that I need to install the citext extension. But how do I do that? There is the following example code but I don't know where to put it.

9 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 1/26/2023 in #support

One or multiple registry.ex in an Ash project?

https://stackoverflow.com/questions/75248367/one-or-multiple-registry-ex-in-an-ash-project

5 replies

AEAsh Elixir

•Created by Stefan Wintermeyer on 1/26/2023 in #support

FeriendatenWeb.AuthController.init/1 is undefined

https://github.com/team-alembic/ash_authentication_phoenix says "This is beta software. Please don't use it without talking to us!". I did use it without talking to you and here we are. 😉 I followed the installation manual for a Phoenix application. When I try to start the server with mix phx.server I'll get the error message

FeriendatenWeb.AuthController.init/1 is undefined (module FeriendatenWeb.AuthController is not available or is yet to be defined)``

I've never created an

AuthController` because the installation manual didn't say so. Is there a step by step tutorial how to start with a vanilla Phoenix application?

17 replies

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