I have a couple of simple models that are associated like so:
MODELS
class Task < ActiveRecord::Base
belongs_to :user
validates :name, :presence => true, :message => 'Name cannot be blank, Task not saved'
end
class User < ActiveRecord::Base
has_many :tasks
end
VIEW has a call in it like so:
user.tasks <-- then I loop through the tasks
The Issue:
In the task model --
when I use:
validates :name, :presence => true , :message => 'Name cannot be blank, Task not saved'
I get a 500 error:
ActionView::Template::Error (uninitialized constant User::Task):
NameError in View file
when I use:
validates_presence_of :name
Everything works.
I thought the both validates methods above where the same...is the issue have to do with associations and how validation tie into associated models. I have a hunch that something is going on with the way things are associated, but it is just a hunch.
Any help will be appreciated. Thank very much.
When you use the newer validates :name format, you can put multiple validations in one line rather than having to have multiple lines for each type of validation. Because of this, when Rails hits your :message parameter, it thinks it's a validation method rather than a message associated with :presence. Try this instead:
validates :name, :presence => {:message => 'Name cannot be blank, Task not saved'}
Also, depending on how you display your errors, this error may actually show up as 'Name Name cannot be....'; if so, you'll want to set the message to just 'cannot be blank, Task not saved'.
Related
I'm importing heaps of student data from an spreadsheet document. Each row of student data will represent a new user, however, the possibility of importing an already existing student exists and I want to bypass some of my user validations such as username uniqueness accordingly so that I can build associations for both new and existing records, but only if they're being imported to the same school.
Thus far I have the following validation setup in my User model:
user.rb
validates_uniqueness_of :username, :unless => :not_unique_to_school?
def not_unique_to_school?
user = find_by_username(self.username)
user.present? && user.school_id == 6
end
Now how would I go about replacing that 6 with a value I have access to in the controller? Instructors will be the ones handling the importing and they'll be importing students to their school so I would typically run current_user.school_id to retrieve the school id that I want them to be imported to, but I don't have access to the current_user helper in my model.
I'm not concerned about duplicating usernames as I'll be handling that on a different step, this is just the preliminary validation.
Edit
Simplified school & user model:
user.rb
class User < ActiveRecord::Base
# Setup accessible (or protected) attributes for your model
attr_accessible :email, :password, :password_confirmation, :remember_me, :username,
:first_name, :last_name, :school_id, :roles_mask
belongs_to :school
validates_presence_of :username, :on => :create, :message => "can't be blank"
validates_uniqueness_of :username, :unless => :unique_to_school?
def unique_to_school?
user = find_by_username(self.username)
user.present? && user.school_id == 6
end
def find_by_username(username)
User.where(:username => username).first
end
end
school.rb
class School < ActiveRecord::Base
attr_accessible :country_id, :name, :state_id
has_many :users
end
I'd add a method to your School model:
def student_named?(name)
self.users.where(:username => name).any?
end
then in your validation:
def not_unique_to_school?
self.school.student_named?(self.username)
end
Here's what ended up working for me:
validate :user_cant_be_duplicate_in_other_schools
def user_cant_be_duplicate_in_other_schools
errors.add(:username, :taken) if User.count(:conditions => ["school_id != ? AND username = ?", self.school_id, self.username]) > 0
end
As opposed to testing if a User belongs to a particular school we're testing for the lack of belonging to a particular school. I didn't come up with this answer, another user posted this as an answer but deleted it shortly after for reasons unknown.
so I have a tricky issue here I'm not sure how to solve.
I have a Provider model that has_many :educational_affiliations
EducationalAffiliation belongs_to :institution & belongs_to
:provider
I have about 9000 universities in my database, so I'm using the handy-dandy rails3-jquery-autocomplete gem to give me type-ahead support. That's all working great - on TOP of that I'm using cocoon to support the nesting of the :educational_affiliations form inside of the provider's edit form.
So here's where the issue comes — This works great for submitting new affiliation records, (I'm using some jquery to set the :institution_id on the :educational_affiliations_attributes object, works great)
BUT when I return to edit this later, of course the :institution_name isn't populated, because it's not part of the :educational_affiliations model, it's in the :institution model.
Here's what I just tried in my :educational_affiliations, which I assume is the right solution:
class EducationalAffiliation < ActiveRecord::Base
attr_accessible :degree, :graduation_year, :honors, :institution_name, :institution_id, :provider_id
belongs_to :institution
belongs_to :provider
# attr_accessor :institution_name
validates :institution_id, :graduation_year, :provider_id, :degree, presence: true
def institution_name
Institution.find(institution_id).name
end
end
(i had it working for saving using the attr_accessor, but I've commented it out for now)
So when I render the edit view with the above, I get a ActiveRecord::RecordNotFound: Couldn't find Institution without an ID error — but when I open a debugger on that statement, the model DOES seem to know the institution_id...so confused why it doesn't pick it up.
Am I just doing this in the worst way possible? I assume there's a dumb solution.. :)
Here's the partial that needs the name populated:
.nested-fields
= f.input :institution_name, url: autocomplete_institution_name_data_path, as: :autocomplete, :input_html => {:id_element => '#provider_educational_affiliations_institution_id'}
= f.input :institution_id, as: :hidden
= f.input :provider_id, as: :hidden, input_html: { value: current_provider.id }
= link_to_remove_association "Remove Degree", f
Instead of the virtual attribute method, try the following to define the attribute:
delegate :name, :name=, :to => :institute, :prefix => true
Here is an example of my problem.
I have a 'Room' model:
class Room < ActiveRecord::Base
has_many :items, :inverse_of => :room
accepts_nested_attributes_for :items
end
And I have an 'Item' model:
class Item < ActiveRecord::Base
belongs_to :room, :inverse_of => :items
validates :some_attr, :uniqueness => { :scope => :room}
end
I want to validate the uniqueness of the :some_attr attribute of all the Items which belongs to a certain room.
When I try to validate the items, I get this error:
TypeError (Cannot visit Room)
I cannot set the scope of the validation to be :room_id since the items are not saved yet so the id is nil. I also want to prevent using custom validators in the 'Room' model.
Is there any clean way to do it in Rails? I also wonder if I set the :inverse_of option correctly...
I don't see anything wrong with how you're using inverse_of.
As for the problem, in a similar situation I ended up forcing a uniqueness constraint in a migration, like so
add_index :items, [ :room_id, :some_attr ], :unique => true
This is in addition to the AR-level validation
validates_uniqueness_of :some_attr, :scope => :room_id
(I'm not sure if it's valid to use the association name as a scope, won't the DB adapter raise an exception when trying to refer to the non-existent room column in a query?)
I have a model User and a nested model Mobility
class User < ActiveRecord::Base
has_many :mobilities, :dependent => :destroy
accepts_nested_attributes_for :mobilities
end
and
class Mobility < ActiveRecord::Base
belongs_to :mobile_user, :class_name => 'User'
validates :city_id, :presence =>true
validates :user_id, :presence =>true
validates :city_id, :uniqueness => {:scope => [:user_id]}
end
my view
=form_for #user, :as => :user, :html =>{ :class => 'form-horizontal'} do |f|
=f.fields_for :mobilities do |city_form|
=city_form.text_field :city_id, :id => "city_id_#{index}"
= f.submit "Retour"
my problem is that when I submit the form Rails render me this validation error:
Mobilities user > doit être rempli(e)
But if a I comment this line:
#validates :user_id, :presence =>true
Both, my Mobility and User objects get saved and know what: user_id field of #mobility is OK (indicatie my #user's ID)
If I send the form with 2 identical mobility inside, both model get saved but it seems my validation of uniqueness didn't check nothing because i have 2 Mobility object with same user_id and city_id in my database...
In fact it seems like my validation can't read my user_id 's key when validating.
I understand that because my User model did'nt get saved yet and doesnt have any ID yet... but that is my question:
How can i check both: presence of user_id and uniqueness with scope ???
What is the difference between validates :presence and validates_presence_of? Looking through ActiveModel it looks like they setup the validation the same way. However, given the following model definition:
class Account < ActiveRecord::Base
has_one :owner_permission, :class_name => 'AccountPermission', :conditions => { :owner => true, :admin => true }
has_one :owner, :class_name => 'User', :through => :owner_permission, :source => :user
validate :owner, :presence => true
validates_associated :owner
end
Calling save on an instance of Account does not validate the presence of owner. Though, if I use validates_presence_of it will.
All those validates_whatever_of :attr macros do is call validates :attr, :whatever => true.
The problem is you are using validate and not validates.
In Rails 3.x and 4.x - it is now encouraged to use the following syntax:
validates :email, presence: true
validates :password, presence: true
Instead of the 2.x way:
validates_presence_of :email
validates_presence_of :password
In fact validates and validates_presence_of is not entirely equal !
validates_presence_of is allowing you to also lazily check by example of the value in the field is included in another table.
Like that:
validates_presence_of :pay_type, :inclusion => PaymentType.names
Which is something you can't do as easily with something like that
validates :pay_type, presence, :inclusion => PaymentType.names
Cause the inclusion is only evaluated the first time (not in a lazy way)
I would have thought that it is appropriate to use validates :foo presence: true when you want to include other validations of :foo such as length or uniqueness. But if you know the only validation you'll need for an attribute is presence, then validates_presence_of appears to be more efficient.
So:
validates :foo, length: {maximum: 50}, uniqueness: true,
format: {with: /bar/},
presence: true # lots of validations needed
But:
validates_presence_of :foo # only presence validation needed