JsonView.render_one
You're seeing just the function
render_one
, go back to JsonView module for more information.
Render one item if not nil, similar to Phoenix.View.render_one/3
It invokes the function render(template, %{model_name: data})
in the view module
Example
render_one(user, MyApp.UserView, "user.json") # then invoke MyApp.UserView.render("user.json", %{user: user})