Your SlideShare is downloading. ×
0
2009 07 21: Nested Attributes
2009 07 21: Nested Attributes
2009 07 21: Nested Attributes
2009 07 21: Nested Attributes
2009 07 21: Nested Attributes
2009 07 21: Nested Attributes
2009 07 21: Nested Attributes
2009 07 21: Nested Attributes
2009 07 21: Nested Attributes
2009 07 21: Nested Attributes
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

2009 07 21: Nested Attributes

860

Published on

How to use simple forms with nested models and single access points into web api's without the view or controller logic getting messy. Demonstration of the Rails 2.3 accepts_nested_attributes_for …

How to use simple forms with nested models and single access points into web api's without the view or controller logic getting messy. Demonstration of the Rails 2.3 accepts_nested_attributes_for feature
Video: http://blip.tv/file/3957941

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
860
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
13
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Wolfram Arnold www.rubyfocus.biz Nested Attributes
      • CRUD
      • on multiple models
      • without crud
  • 2. Associations
    • class Pirate < ActiveRecord::Base has_one :ship end
    • class Ship < ActiveRecord::Base belongs_to :pirate end
  • 3. User Interface?
    • Form with pirate and ship fields
      • form_for :pirate do |pf| pf.text_field :catchphrase pf.fields_for :ship do |sf| sf.text_field :name end # params[pirate][ship] # Note: broken! end
  • 4. Controller Interface?
      • def create @pirate = Pirate.new(params[:pirate]) @ship = Ship.new(params[:pirate][:ship]) @ship.pirate = @pirate if @pirate.save && @ship.save ... else # what about rollback? end end
  • 5. Demo
  • 6. Fat model/skinny controller
    • Logic in the model, not views/controllers
    • Assignments
      • class Pirate < ActiveRecord::Base def ship_attributes=(attrs) ... end end
    • Validations handled in model, incl. child models
  • 7. Saving—when?
    • :autosave => true flag, new in Rails 2.3!
    • Automatically turned on for accepts_nested_attributes_for
    • Parent will save all children
      • New parent, modified children
      • Existing parent, new/modified children
      • As a transaction—rollback on validation failure
      • Cascaded error messages
    • Removes a lot of confusion
    • Demo
  • 8. Web Service API
    • PirateController and ShipController?
    • Not advised if
      • Objects have a relationship, e.g. has_one association
      • Dependencies
      • Business logic rules/validations
    • Better single API with nested attributes
      • Simpler client code
      • Less network traffic
  • 9. References
    • http://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html#M002132
    • http://github.com/h-lame/parental_control
    • http://railscasts.com/episodes/75-complex-forms-part-3
    • Advanced Rails Recipes, Pragmatic Programmer Series
  • 10. Wolfram Arnold www.rubyfocus.biz
      • Thank you!

×