Rails scaffold_controller generator doesn't apply model attributes to views

Question

I'm using the scaffold_controller generator on an existing model with existing attributes, but the view forms that get generated don't have any input controls for the corresponding model attributes - they're just empty forms. Why is that?

e.g:

rails generate scaffold_controller User --skip --no-test-framework

Where the User already has name and email attributes should generate forms with name and email fields...

Answer 1

This is what it is supposed to do. When calling scaffold_controller you're telling the generator to not use a model. If you want to have form attributes in the views, you need to pass them to the generator just like you would a normal scaffolding.

rails g scaffold_controller User name email

Answer 2

In rails 5, you can get the list of columns with type using following code.

Model.columns.reject{|n| n.name == "id" or n.name == "created_at" or n.name == "updated_at" }.map{|i| "#{i.name}:#{i.type}"}.join(" ")

Later you can paste the output post rails g scaffold_controller Model

Answer 3

I agree that it sucks to have to keyboard all the attributes yourself, with the danger of misspelling name or type, when the info is just sitting there in the model. Here is a monkey patch I wrote to interpolate the column names and types (at least in Rails 4). Put this code in an .rb file in the #{Rails.root}/config/initializers directory:

# patch to scaffold_controller to read model attributes
# if none specified on command line (and model exists)
# usage: rails g scaffold_controller <MODEL>

if ARGV.size > 0 and ARGV[0] == "scaffold_controller"
    puts "\n\n\n\n"
    puts "monkey patch attributes at #{Time.now}"

    Rails::Generators::NamedBase.class_eval do

        # parse_attributes! converts name:type list into GeneratedAttribute array
        # must be protected; thor enumerates all public methods as commands
        # and as I found out will call this and crash otherwise
        protected
        def parse_attributes! #:nodoc:
          # get model columns into col:type format
          self.attributes = get_model_attributes if not self.attributes or self.attributes.empty?
          # copied from default in named_base.rb
          self.attributes = (self.attributes || []).map do |attr|
            Rails::Generators::GeneratedAttribute.parse(attr)
          end
        end

        # get model columns if no attributes specified on command line
        # fake it by creating name:type args
        private
        def get_model_attributes
            # fill from model
            begin
                mdl = class_name.to_s.constantize
                # don't edit id, foreign keys (*_id), timestamps (*_at)
                attrs = mdl.columns.reject do |a|
                    n = a.name
                    n == "id" or n.end_with? "_id" or n.end_with? "_at"
                end .map do |a|
                    # name:type just like command line
                    a.name+":"+a.cast_type.type.to_s
                end
                puts "model_attributes(#{class_name})=#{attrs}"
                return attrs
            rescue => ex
                puts ex
                puts "problem with model #{class_name}"
                return nil
            end
        end

    end

end