Elixir/Phoenix enum through tuple to replace paths - tuples

Question

I'm parsing some HTML with Floki. And receive the following tuple:
{"html", [{"lang", "en"}],
[{"head", [],
[{"title", [], ["My App"]},
{"link", [{"rel", "stylesheet"}, {"href", "/css/app.css"}], []}]},
{"body", [],
[{"main", [{"id", "main_container"}, {"role", "main"}], []},
{"script", [{"src", "/js/app.js"}], [""]},
{"iframe",
[{"src", "/phoenix/live_reload/frame"}, {"style", "display: none;"}],
[]}]}]}
Is it possible to enumerate through all the elements, and for those that have href or src add full path to them? For example in this case replace them with: http://localhost/css/app.css and http://localhost/js/app.js

Answer 1

Here's one way you could do it using a recursive function.
defmodule HTML do
def use_full_path({el, attrs, children}) do
{el, update_attrs(attrs), Enum.map(children, &use_full_path/1)}
end
def use_full_path(string) do
string
end
defp update_attrs(attrs) do
Enum.map(attrs, fn {key, val} ->
if key in ["href", "src"] do
{key, "http://localhost" <> val}
else
{key, val}
end
end)
end
end
tree = {"html", [{"lang", "en"}],
[{"head", [],
[{"title", [], ["My App"]},
{"link", [{"rel", "stylesheet"}, {"href", "/css/app.css"}], []}]},
{"body", [],
[{"main", [{"id", "main_container"}, {"role", "main"}], []},
{"script", [{"src", "/js/app.js"}], [""]},
{"iframe",
[{"src", "/phoenix/live_reload/frame"}, {"style", "display: none;"}],
[]}]}]}
HTML.use_full_path(tree) |> IO.inspect