A set of functions used with Phoenix views.

Typically, this module should be imported into your view modules. In a normal phoenix application, this can usually be done with the following:

defmodule YourAppWeb do
# ...

  def view do
    quote do
      use Phoenix.View, root: "lib/your_app_web/templates", namespace: "web"

      # ...

      import Versioning.View

      # ...
    end
  end
end

Please see the documentation at Phoenix.View for details on how to set up a typical view.

In places that you would use Phoenix.View.render_one/4, this module provides render_version/6. In places that you would use Phoenix.View.render_many/4, this module provides render_versions/6.

In order to use these functions, you must already have applied the schema and requested version to the conn. This is typically done with Versioning.Plug or through the helpers available in Versioning.Controller.

Example

Below is an example of how to use versioning in a typical view:

defmodule YourApp.UserView do
  use YourApp.View

  def render("index.json", %{conn: conn, users: users}) do
    %{
      "users" => render_versions(conn, users, "User", UserView, "user.json"),
    }
  end

  def render("show.json", %{conn: conn, users: users}) do
    %{
      "user" => render_version(conn, users, "User", UserView, "user.json"),
    }
  end

  def render("user.json", %{user: user}) do
    %{"name" => user.name, "address" => user.address}
  end
end

A typical call, such as:

render_many(users, UserView, "user.json")

Is replaced by the following:

render_versions(conn, users, "User", UserView, "user.json")

In order to render versions of our data, we must pass the conn struct, our data to be versioned, the type the data represents in our schema, the view module to use, the template to use, as well as an additional assigns.

The contents of the "user.json" template represent the latest version of your data. They will be run through your versioning schema to the version requested by the user. The output returned by your schema is what will be finally rendered.