method

attributes=

v3.1.0 - Show latest stable - Class: ActiveRecord::Base

attributes=(new_attributes, guard_protected_attributes = nil)

public

Allows you to set all the attributes at once by passing in a hash with keys matching the attribute names (which again matches the column names).

If any attributes are protected by either attr_protected or attr_accessible then only settable attributes will be assigned.

The guard_protected_attributes argument is now deprecated, use the assign_attributes method if you want to bypass mass-assignment security.

class User < ActiveRecord::Base
  attr_protected :is_admin
end

user = User.new
user.attributes = { :username => 'Phusion', :is_admin => true }
user.username   # => "Phusion"
user.is_admin?  # => false

# File activerecord/lib/active_record/base.rb, line 1687
      def attributes=(new_attributes, guard_protected_attributes = nil)
        unless guard_protected_attributes.nil?
          message = "the use of 'guard_protected_attributes' will be removed from the next minor release of rails, " +
                    "if you want to bypass mass-assignment security then look into using assign_attributes"
          ActiveSupport::Deprecation.warn(message)
        end

        return unless new_attributes.is_a?(Hash)

        if guard_protected_attributes == false
          assign_attributes(new_attributes, :without_protection => true)
        else
          assign_attributes(new_attributes)
        end
      end

3Notes

Update attributes on mulitple models

patrickberkeley · Oct 1, 2009

Updates attributes on multiple models, saves each if validations pass.

def update_multiple
@items = Item.find(params[:item_ids])
@items.each do |item|
  item.attributes = params[:item].reject { |k,v| v.blank? }
end
if @items.all?(&:valid?)
  @items.each(&:save!)
  flash[:notice] = "Updated items!"
  redirect_to items_path
else
  flash[:notice] = "Please enter valid data."
  render :action => 'edit_multiple'
end
end

Use super to override, and not alias_method_chain

THAiSi · Oct 26, 2010

Somehow, If you want to extend the behaviour of attributes=,

alias_method_chain does not work. It simply breaks (could not find out how exactly).

def attributes_with_some_feature=(new_attributes, guard_protected_attributes = true)
attributes_without_some_feature=(new_attributes, guard_protected_attributes)
end
alias_method_chain :attributes=, :some_feature

this breaks the code. dynamic finders and assignments didn't work as before (Even though no behaviour has changed yet).

Instead,

def attributes=(new_attributes, guard_protected_attributes = true)
# custom code
super(new_attributes, guard_protected_attributes)
end

does work as expected.

I prefer using alias_method_chain for breaking open existing functionality, but in this case it won't work.

the source is wrong!

abstraktor · Apr 6, 2011

in 3.0.5, the source code in line 15 looks like this: respond_to?(:"#{k}=") ? send(:"#{k}=", v) : raise(UnknownAttributeError, "unknown attribute: #{k}")

whats wrong with apidock?