Hi everyone

Problem with some code highlighting for this part of the series. An issue has been opened.

Welcome to part 7 of the series but before we jump in let's recap what we did in the sixth part:

• homework: Create a Context Accounts with a User Schema and a Users Migration with username field and password field.

• Bonus: Create a User query and a User type.

How was this exercise for you Dear Reader did you managed to build it?

Section navigation

• User context with schema and migration

• User query and user type

So we will have two sections today in the first part we are going to create a Context Accounts with a User Schema and a Users Migration with username field and password field.

In the second part, we are going to create a User query and a User type.

#Section 1 User context with schema and migration

Let's create a new branch using:

hub checkout -b 01-User 

mix phx.gen.context Accounts User users username:unique password
mix ecto.migrate

With these commands we finished the first part of our homework and can add our work to git

hub add .

hub commit -m "User context with schema and migration"

hub push --set-upstream origin 01-User

#Section 2 User query and user type

Create a new file in: lib/wolf_blog_web/types and call it user_types.ex

defmodule WolfBlogWeb.Types.UserTypes do
  use Absinthe.Schema.Notation

  @desc "User fields that can be interrogated(get)"
  object :user do
    @desc "The user id"
    field :id, :id
    @desc "The username of the user"
    field :username, :string
    @desc "The password of the user"
    field :password, :string
  end
end

Now change schema.ex to this:

defmodule WolfBlogWeb.Schema do
  use Absinthe.Schema
  alias WolfBlogWeb.Resolvers.PostResolver

  import_types(WolfBlogWeb.Types.PostTypes)
  import_types(WolfBlogWeb.Types.UserTypes)

  query do
    @desc "list_all_posts"
    field :posts, list_of(:post) do
      resolve(&PostResolver.list_all_posts/3)
    end

    @desc "list_all_users"
    field :users, list_of(:user) do
      resolve(&UserResolver.list_all_users/3)
    end
  end
end

The new part that we added to the schema.ex is this:

@desc "list_all_users"
 field :users, list_of(:user) do
 resolve(&UserResolver.list_all_users/3)
 end

This completes the bonus section of the homework Dear Reader.

But wait, Wolfiton I get an error that my resolver is not found?!

I am glad you noticed Dear Reader

As you can remember from our previous articles in these series. To make Phoenix and Absinthe work together we need a Resolver to connect the Context with our Schema.

So in lib/wolf_blog_web/resolvers, create a new file called user_resolver.ex

defmodule WolfBlogWeb.Resolvers.UserResolver do
  alias WolfBlog.Accounts

  def list_all_users(_, _, _) do
    {:ok, Accounts.list_users()}
  end
end

So now we only need to add this alias in schema.ex:

alias WolfBlogWeb.Resolvers.UserResolver

So our schema.ex will look like this:

defmodule WolfBlogWeb.Schema do
  use Absinthe.Schema
  alias WolfBlogWeb.Resolvers.PostResolver
  alias WolfBlogWeb.Resolvers.UserResolver

  import_types(WolfBlogWeb.Types.PostTypes)
  import_types(WolfBlogWeb.Types.UserTypes)

  query do
    @desc "list_all_posts"
    field :posts, list_of(:post) do
      resolve(&PostResolver.list_all_posts/3)
    end

    @desc "list_all_users"
    field :users, list_of(:user) do
      resolve(&UserResolver.list_all_users/3)
    end
  end
end

Now let's add all our modifications to GitHub:

hub add .

hub commit -m "Added User query with user types and a user resolver"

hub push

Part 7 is finished, I hope you enjoyed Dear Reader.

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