Unpermitted parameters on with accepts_nested_attributes_for

Question

So I'm fairly new to Rails so I'm probably missing something quite straight forward.. What I'm trying to do is create an `Artist` when creating a `Band`. Models band.rb ``` class Band < ActiveRecord::Base has_many :artists, dependent: :destroy accepts_nested_attributes_for :artists, allow_destroy: true ... end ``` artist.rb ``` class Artist < ActiveRecord::Base belongs_to :band ... end ``` Controller band_controller.rb ``` class BandController < ApplicationController def new @band = Band.new end def create @band = Band.new(band_params) if @band.save ... else ... end end private def band_params params.require(:band).permit(:name, :hometown, :email, :artist, artist_attributes: [ :band_id, :first_name, :last_name, :email, :password, :password_confirmation ]) end end ``` View new.html.erb ``` <%= form_for(@band, url: "/artist/signup") do |f| %> <%= render 'shared/error_messages', object: f.object %> <%= f.fields_for :artist do |artist| %> <%= artist.text_field :first_name, :placeholder =>…

Accepted Answer

Ok, with some help from #RubyOnRails I have got it figured out.

I needed to build the artists in the new action of BandController

```
@band.artists.build
```

That then gets pulled through into the view via `form_for(@band)`, with `.fields_for :artist` changing to `.fields_for :artists`, and

```
  params.require(:band).permit(:name, :artist, artist_attributes: [ :band_id, :first_name ])
```

changing to

```
  params.require(:band).permit(:name, artists_attributes: [ :band_id, :first_name ])
```

Unpermitted parameters on with accepts_nested_attributes_for

Solution

Problem