How to use strong parameters to refactor code

Question

I'm new to Ruby on Rails and don't understand private methods using strong params.

How would I refactor this? Can someone give me an example?

I've tried looking it up, but all I find are examples of CRUD using strong params in CRUD.

def create
    title = params["song"]["title"]
    rating = params["song"]["rating"]
    artist_id = params["song"]["artist_id"]
    song = Song.create(title: title, rating: rating, artist_id: 
    artist_id)
    redirect_to song_path(song)
end

def update
    title = params["song"]["title"]
    rating = params["song"]["rating"]
    artist_id = params["song"]["artist_id"]
    song = Song.find(params[:id])
    song.update(title: title, rating: rating, artist_id: artist_id)
    redirect_to song_path(song)
end

Answer 1

Have you tried anything like this? Note that you're not managing errors here

def create
    song = Song.create(song_params)
    redirect_to song_path(song)
end

def update
    song = Song.find(params[:id])
    song.update(song_params)
    redirect_to song_path(song)
end

private

def song_params
  params.require(:song).permit(:title, :rating, :artist_id)
end

In this line you're simply whitelisting those three params' names in a song object and this method is called in the create and update actions

params.require(:song).permit(:title, :rating, :artist_id)

This means that if a duration was sent inside the song object that attribute is not changed because it's not whitelisted