Rails: Ignoring non-existant attributes passed to create()

Question

I have the following Rails model:

class CreateFoo < ActiveRecord::Migration
  def self.up
    create_table :foo do |t|
      t.string :a
      t.string :b
            


        

Answer 1

Re: Is there a way I can get create() to ignore attributes that don't exist in the model? -- No, and this is by design.

You can create an attr_setter that will be used by create --

attr_setter :a # will silently absorb additional parameter 'a' from the form.

Re: Alternatively, what is the best way to remove non-existent attributes prior to creating the new record?

You can remove them explicitly:

params[:Foo].delete(:a) # delete the extra param :a

But the best is to not put them there in the first place. Modify your form to omit them.

Added:

Given the updated info (incoming data), I think I'd create a new hash:

incoming_data_array.each{|rec|
  Foo.create {:a => rec['a'], :b => rec['b'], :c => rec['c']} # create new
                                                              # rec from specific
                                                              # fields
}

Added more

# Another way:
keepers = ['a', 'b', 'c'] # fields used by the Foo class.

incoming_data_array.each{|rec|
  Foo.create rec.delete_if{|key, value| !keepers.include?(key)} # create new rec
}                                                               # from kept
                                                                # fields

Answer 2

Trying to think of a potentially more efficient way, but for now:

hash = { :a => 'some', :b => 'string', :c => 'foo', :d => 'bar' }
@something = Something.new
@something.attributes = hash.reject{|k,v| !@something.attributes.keys.member?(k.to_s) }
@something.save