learn_category.ex

defmodule TrangellCmsService.Cms.Db.LearnCategory do
use Ecto.Schema

    import Ecto.Changeset
    @primary_key {:id, :binary_id, autogenerate: true}
    @foreign_key_type :binary_id

    schema "cms_learn_category" do

      field :title, :string
      field :status, :boolean
      field :language, :string
      field :group_acl, :string


      field :seo_alias_link, :string
      field :seo_words, :string
      field :seo_description, :string
      field :seo_language, :string
      field :seo_language_link, :string

      field :pic_x1_link, :string
      field :pic_x2_link, :string
      field :pic_x3_link, :string

      has_many :cms_learn_headlines, TrangellCmsService.Cms.Db.LearnHeadlines,  foreign_key: :cms_learn_category_id
      has_many :cms_learn_post, TrangellCmsService.Cms.Db.LearnPost,  foreign_key: :cms_learn_category_id

      timestamps()
    end

    @all_fields ~w(title status language group_acl seo_alias_link seo_words seo_description seo_language seo_language_link pic_x1_link pic_x2_link pic_x3_link)a

    def changeset(struct, params \\ %{}) do
        struct
        |> cast(params, @all_fields)
        |> validate_required(@all_fields)
        |> validate_inclusion(:group_acl, ["admin", "actived", "unactived", "blocked"])
        |> validate_inclusion(:language, ["en", "fa"])
        |> validate_inclusion(:seo_language, ["en", "fa"])
        |> unique_constraint(:seo_alias_link, name: :index_of_learn_categories_alias_unique_link, message: "alias link already exists.")
    end

end

learn_headlines.ex

defmodule TrangellCmsService.Cms.Db.LearnHeadlines do
use Ecto.Schema

    import Ecto.Changeset
    @primary_key {:id, :binary_id, autogenerate: true}
    @foreign_key_type :binary_id


    schema "cms_learn_headlines" do

        field :title, :string
        field :status, :boolean
        field :language, :string
        field :group_acl, :string
        field :description, :string

        field :seo_alias_link, :string
        field :seo_words, :string
        field :seo_description, :string
        field :seo_language, :string
        field :seo_language_link, :string


        belongs_to :cms_learn_category, TrangellCmsService.Cms.Db.LearnCategory, foreign_key: :cms_learn_category_id, type: :binary_id
        has_many :cms_learn_post, TrangellCmsService.Cms.Db.LearnPost,  foreign_key: :cms_learn_headlines_id
        timestamps()
    end

    @all_fields ~w(title status language group_acl description seo_alias_link seo_words seo_description seo_language seo_language_link cms_learn_category_id)a
    def changeset(struct, params \\ %{}) do
        struct
        |> cast(params, @all_fields)
        |> validate_required(@all_fields)
        |> validate_inclusion(:language, ["en", "fa"])
        |> validate_inclusion(:seo_language, ["en", "fa"])
        |> validate_inclusion(:group_acl, ["admin", "actived", "unactived", "blocked"])
        |> unique_constraint(:seo_alias_link, name: :index_of_learn_headlines_alias_unique_link, message: "alias link already exists.")
        |> foreign_key_constraint(:cms_learn_category_id)
        |> validate_field_relational(:cms_learn_category_id)
    end

    defp validate_field_relational(changeset, field) do
      field_concerned = get_field(changeset, field)
      case Ecto.UUID.cast(field_concerned) do
        :error ->
            add_error(changeset, field, "relational field is invalid")
        _ ->
          changeset
      end
    end

end

learn_post.ex

defmodule TrangellCmsService.Cms.Db.LearnPost do
use Ecto.Schema

    import Ecto.Changeset
    @primary_key {:id, :binary_id, autogenerate: true}
    @foreign_key_type :binary_id


    schema "cms_learn_post" do

        field :title, :string
        field :status, :boolean
        field :group_acl, :string
        field :short_description, :string
        field :description, :string

        field :seo_alias_link, :string
        field :seo_words, :string
        field :seo_description, :string
        field :seo_language, :string
        field :seo_language_link, :string


        belongs_to :cms_learn_category, TrangellCmsService.Cms.Db.LearnCategory, foreign_key: :cms_learn_category_id, type: :binary_id
        belongs_to :cms_learn_headlines, TrangellCmsService.Cms.Db.LearnHeadlines, foreign_key: :cms_learn_headlines_id, type: :binary_id
        timestamps()
    end

    @all_fields ~w(title status group_acl short_description description seo_alias_link seo_words seo_description seo_language seo_language_link cms_learn_category_id cms_learn_headlines_id)a
    def changeset(struct, params \\ %{}) do
        struct
        |> cast(params, @all_fields)
        |> validate_required(@all_fields)
        |> validate_inclusion(:seo_language, ["en", "fa"])
        |> validate_inclusion(:group_acl, ["admin", "actived", "unactived", "blocked"])
        |> unique_constraint(:seo_alias_link, name: :index_of_learn_posts_alias_unique_link, message: "alias link already exists.")
        |> foreign_key_constraint(:cms_learn_category_id)
        |> foreign_key_constraint(:cms_learn_headlines_id)
        |> validate_field_relational(:cms_learn_category_id)
        |> validate_field_relational(:cms_learn_headlines_id)
        # |> check_constraint(:cms_learn_category_id)
        # |> check_constraint(:cms_learn_headlines_id)
    end

    defp validate_field_relational(changeset, field) do
      field_concerned = get_field(changeset, field)
      case Ecto.UUID.cast(field_concerned) do
        :error ->
            add_error(changeset, field, "relational field is invalid")
        _ ->
          changeset
      end
    end
end