Horribly redundant Phoenix controller

Question

I'm doing my first Phoenix application, and trying to do new/2 controller. The code I wrote is

def new(conn, %{"fbid" => fbid, "latitude" => lat, "longitude" => lng, "content" => content}) do
    {fbid, _} = Integer.parse(fbid);
    {lat, _} = Float.parse(lat);
    {lng, _} = Float.parse(lng);

    chats = %Chat{:fbid => fbid, :latitude => lat, :longitude => lng, :content => content}
      |> Repo.insert
      |> List.wrap
      |> Poison.encode!
    render conn, chats: chats
end

But it looks horribly redundant and I can't find any better way to do this. I've read that there is no way to convert Map to Struct, and since the params differ in type it wouldn't work anyway.

So can anybody show me some magic way to map it?

Answer 1

Please look into Ecto changesets as they do casting based on your model information. They are going to take care of all the parsing, validation and more.

My advice is to use one of mix phoenix.gen.html or mix phoenix.gen.json to generate some sample structure so you learn quickly how all the pieces fit together:

mix phoenix.gen.html Chat chats fbid:integer latitude:float longitude:float content:string

Note thought the generator will conflict with your code above if you have already defined a Chat model.