CODEWITHSUNDEEP
elixirphoenix-framework
Galina Kazlova
Galina Kazlova

Reputation: 55

Random router in Phoenix framework

I want to route incoming requests randomly.

So far I've only come up with this:

defmodule Test.PageController do
  use Test.Web, :controller

  plug :assign_random_number

  def index(%{assigns: %{random_number: random_number}} = conn, _params)
    when random_number > 0.1 do
    render conn, "index.html", fortune: "one"
  end
  def index(conn, _params) do
    render conn, "index.html", fortune: "two"
  end

  defp assign_random_number(conn, _params) do
    :random.seed(:erlang.now)
    assign(conn, :random_number, :random.uniform)
  end
end

Is it possible to have this "randomization" logic in router.ex? Like in Sinatra

get "/", :random_number > 0.1 do
  "one"
end

get "/" do
  "two"
end

Upvotes: 2

Views: 125

Answers (1)

fny
fny

Reputation: 33537

You can't (and shouldn't) do that in Elixir at the routing level. In fact, you can't even do that in Sinatra! The code you posted is invalid Ruby:

get "/", :random_number > 0.1 do
  "one"
end
# => ArgumentError: comparison of Symbol with 0.1 failed

Here's how'd you'd actually accomplish this in Sinatra:

get "/" do                        # <- Routing layer
  rand > 0.1 ? 'one' : 'two'      # <- Response/controller layer
end

Note that we're depending on our response/controller layer to handle the randomization. We can do something similar in Elixir:

defmodule Test.PageController do
  use Test.Web, :controller

  def index(conn, _params) do
    render conn, "index.html", fortune: make_fortune
  end

  defp make_fortune do
    if :random.uniform > 0.1, do: "one", else: "two"
  end
end

Upvotes: 1

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