I have model Question, Answer and AnswerDetail.
Answer:
class Answer < ActiveRecord::Base
has_many :answer_details, :dependent => :destroy
accepts_nested_attributes_for :answer_details, :allow_destroy => true
validates_associated :answer_details
end
AnswerDetail:
class AnswerDetail < ActiveRecord::Base
belongs_to :answer
belongs_to :question
validates_presence_of :answer_field, :if => lambda {isrequired == true}, :message => "This is required field"
end
The isrequired field is from the model Question.
Question:
class Question < ActiveRecord::Base
has_one :answer_detail
end
The AnswerDetal model has the question_id and answer_id field on it. I want to filter the answer_field if the isrequire field from Question model is equal to true? How I will do this? How to access the has_one association's attribute inside model?
I've done this before, although I've not got the code handy right now:
Nested
From what I remember, you can actually put the validation in the nested model:
#app/models/question.rb
class Question < ActiveRecord::Base
validates :answer_field, presence: true, if: lambda {isrequired == true}
end
I highly recommend using the new validates syntax
--
inverse_of
I'm sure I had to use inverse_of somewhere in the code I had (it's locked in a private GitHub repo sorry).
inverse_of basically includes the associated model in your current model. Much like how you've found the effectiveness of self.question.isrequired:
#app/models/answer_detail.rb
class AnswerDetail < ActiveRecord::Base
belongs_to :question, inverse_of: :answer_detail
validates :answer_field, presence: true, if: lambda { question.isrequired == true }
end
#app/models/question.rb
class Question < ActiveRecord::Base
has_one :answer_detail, inverse_of: :question
end
However, good news for you:
This is not the answer, this is how I would troubleshoot
Inspect in:
validates_presence_of :answer_field, :if => lambda {isrequired == true}, :message => "This is required field"
What variables you have available, you can do this with pry-rails gem. Like this:
validates_presence_of :answer_field, :if => lambda {binding.pry; isrequired == true}, :message => "This is required field"
When trying to save a question you will get a interactive console(in the server terminal window) where you can print values like self or do this:
validates_presence_of :answer_field, :if => lambda {|record| binding.pry; isrequired == true}, :message => "This is required field"
And print record.
Then you can try finding where Question is stored with: self.question or record.question.
I tried using self.question.isrequired and it is working. But maybe you have other nice suggestion to do the error validation. Thank you.
Related
I am working on a self-learning Rails application (the source code can be found here. I want to validate the presence of the content before posting a text or an image:
.
Those are my models or look below:
class Post < ActiveRecord::Base
belongs_to :user
default_scope { order ("created_at DESC")}
belongs_to :content, polymorphic: true
has_reputation :votes, source: :user, aggregated_by: :sum
end
class PhotoPost < ActiveRecord::Base
has_attached_file :image, styles: {
post: "200x200>"
}
end
class TextPost < ActiveRecord::Base
attr_accessible :body
end
Here are my controllers in case they have a relation with this. Any other files can be found in my Github account. I am sure it will be messy to copy the whole project (that is why I am giving links for the controllers and for my project).
So what I have tried so far. (I tried those on the Posts Model)
=> Using validates_associated
validates_associated :content, :text_post
and getting an error "undefined method `text_post' for #Post:0x517c848>"
=> Used validates
validates :content, :presence => true
and getting no error however a post is created with no text.
validates :body, :presence => true
and getting an error "undefined method `body' for #Post:0x513e4a8>"
If you need any other information please let me know and I will provide it asap.
Thank you.
It would seem you have quite a confusing model setup with some key missing relation rules. E.g. Polymorphic rule which is not being utilised and a has_many relation between User and Post with no sign a of a user_id value in the Post model. Here is how I would set it up:
User.rb
def User << ActiveRecord::Base
has_many :text_posts
has_many :photo_posts
end
TextPost.rb
def TextPost << ActiveRecord::Base
attr_accessible :body, :user_id
belongs_to :user
validates :body, :presence => true
end
PhotoPost.rb
def PhotoPost << ActiveRecord::Base
attr_accessible :image, :user_id
belongs_to :user
validates :file, :presence => true, :format => {
:with => %r{\.(gif|png|jpg)$}i,
:message => "must be a URL for GIF, JPG or PNG image."
}
end
Then in your view you would need to do:
<%= form_for #text_post do |f| %>
# ...
<% end %>
And in your controller you can modify the create method to include the current_user from devise and assign it to the new text post record (user_id attribute):
text_posts_controller.rb
def create
#text_post = current_user.text_posts.new(params[:text_post])
end
This adheres more to the DRY principle which Ruby on Rails excels at - you shouldn't be writing alot of code to just create a new record.
I would advise on reading up on some Ruby on Rails standard and best practises. You shouldn't need to create a method in the Dashboard Model in order to create a new TextPost or PhotoPost record. This is a very confusing way of going about it; instead you should be utilising the power of ActiveRecord relation.
I would advise checking out Railscasts. They have alot of fulfilling content.
I have a polymorphic association (contact_details) in my Company model and I want to validate the parent model. Note: I am using accepts_nested_attributes_for in my parent model.
The basic rule:
the company must have at least one phone (phone is the kind of
contact_detail)
The problem:
accepts_nested_attributes_for call destroy for child objects AFTER
validation of the parent object
so the user are able to delete a phone. Of course, later, when the user will try to edit a company without a phone, he/she will get an error (The company must have at least one phone).
Company (Parent) model:
class Company < ActiveRecord::Base
PHONES_NUMBER_MIN = 1
attr_accessible :name, :contact_details_attributes, ...
has_many :contact_details, :as => :contactable, :dependent => :destroy
validate do |company|
check_phones_number
end
accepts_nested_attributes_for :contact_details, :allow_destroy => true, :reject_if => :all_blank
private
def phones_number_valid?
kind = ContactDetail::Kind.phone
phones = contact_details.select { |cd| cd.kind_id == kind.id }
phones.size >= PHONES_NUMBER_MIN
end
def check_phones_number
unless phones_number_valid?
errors.add(:base, :phones_too_short, :count => PHONES_NUMBER_MIN)
end
end
...
end
ContactDetail (Child) model:
class ContactDetail < ActiveRecord::Base
attr_accessible :kind_id, :kind_value_source
belongs_to :contactable, :polymorphic => true
belongs_to :kind
validates :kind_value_source, :presence => true, :length => {:maximum => 255}
...
end
Note: I simplified the original version, so objective was clear to you. Here is the gist with the code.
By using the reject_if option I am able to forbid the deletion of all the phones. It is probably the best option by now. But I want to hear your opinions.
I also found this question and tried to apply the answer, but it didn't helped a lot. The same problem, as I described above. I've drawn a flowchart so you can see the trace, as I see it.
How can I validate the parent model in such a case?
I would be grateful for any help.
From the question you referenced, you can get rid of the reject_if and modify the line in phones_number_valid?:
phones = contact_details.select { |cd| cd.kind_id == kind.id && !cd.marked_for_destruction? }
So I have two models here:
class Screen < ActiveRecord::Base
belongs_to :user
validates :screen_size, :numericality =>{:less_than_or_equal_to =>100,:greater_than_or_equal_to => 0},:if => "user.access==1"
class User < ActiveRecord::Base
has_many :screens
attr_accessible :access
But this code doesn't work, cause no matter what value the user.access is, it will still execute the validation. What am I doing wrong here?
Thank you
change:
:if => "user.access==1"
with:
:if => lambda { |screen| screen.user.try(:access) ==1 }
Because:
you need to pass a function to evaluate condition on the fly
if your screen doesn't have any user, a mere screen.user.access would throw an exception
You passed in a string to the :if executable proc/function parameter. When this is a string, it tries to find a function with that name. What you actually want is an anonymous function here using a lambda.
class Screen < ActiveRecord::Base
belongs_to :user
validates :screen_size, :numericality => {:less_than_or_equal_to =>100, :greater_than_or_equal_to => 0}, :if => lambda {|s| s.user.access == 1 }
end
class User < ActiveRecord::Base
has_many :screens
attr_accessible :access
end
Let's say you have a SiteUpdate and a Comment model, and you want to make Comment polymorphic. You make comment hold a "commentable_id" and "commentable_type"...
Here's our comment model:
class Comment < ActiveRecord::Base
belongs_to :commentable, :polymorphic => true
validates_presence_of :content
validates_presence_of :commentable
end
Here is our SiteUpdate:
class SiteUpdate < ActiveRecord::Base
belongs_to :author, :class_name => 'User', :foreign_key => 'author_id'
has_many :comments, :as => :commentable
validates_presence_of :subject
validates_length_of :subject, :maximum => 80
validates_presence_of :intro
validates_length_of :intro, :maximum => 200
validates_presence_of :text
validates_presence_of :author
scope :sorted, order("site_updates.created_at desc")
end
Does Rails link the commentable to the site_update instance, or do I have to do that manually?
#site_update.comments << Factory.build(:comment, :commentable_id => nil)
#site_update.save
This fails -> it complains that the comment.commentable_id should not be blank (I set this validation in the Comment model).
So do I do this manually, or do I set this up incorrectly?
Or do I just not validate it at all?
I'm making an assumption that your #site_update object is a new object. If so...
There's a somewhat annoying thing about rails associations. You can't really add them before the record is saved.
What's happening is, you have a new site update object without an ID. You build a new comment object for that site update, so it sets the commentable_type to "SiteUpdate", however, there's no ID yet, so it sets the commentable_id to nil. You save, and it bubbles out to save associated objects, but it doesn't set the comment commentable_id to the SiteUpdate ID, because it doesn't exist.
So if you change it around to be :
#site_update.save
#site_update.comments << Factory.build(:comment, :commentable_id => nil)
#site_update.comments.map { |c| c.save }
it should work.
If it's not a new record...it should work as is.
Is it posible to validate the uniqueness of a child model's attribute scoped against a polymorphic relationship?
For example I have a model called field that belongs to fieldable:
class Field < ActiveRecord::Base
belongs_to :fieldable, :polymorphic => :true
validates_uniqueness_of :name, :scope => :fieldable_id
end
I have several other models (Pages, Items) which have many Fields. So what I want is to validate the uniqueness of the field name against the parent model, but the problem is that occasionally a Page and an Item share the same ID number, causing the validations to fail when they shouldn't.
Am I just doing this wrong or is there a better way to do this?
Just widen the scope to include the fieldable type:
class Field < ActiveRecord::Base
belongs_to :fieldable, :polymorphic => :true
validates_uniqueness_of :name, :scope => [:fieldable_id, :fieldable_type]
end
You can also add a message to override the default message, or use scope to add the validation:
class Field < ActiveRecord::Base
belongs_to :fieldable, :polymorphic => :true
validates_uniqueness_of :fieldable_id, :scope => [:fieldable_id, :fieldable_type], :message => 'cannot be duplicated'
end
As a bonus if you go to your en.yml, and enter:
activerecord:
attributes:
field:
fieldable_id: 'Field'
You are going to replace the default 'subject' that rails add to the errors with the one you specify here. So instead of saying: Fieldable Id has been already taken or so, it would say:
Field cannot be duplicated