I'm playing with rails again and found this behavior, when i create a new instance of a Post model with some attributes it tells me that all attributes are nil, why it is happening?
Loading development environment (Rails 4.0.0)
2.0.0-p451 :001 > a = Post.new(title: "Rails", content: "Rails Post")
=> #<Post id: nil, title: nil, content: nil, author: nil, rating: nil, created_at: nil, updated_at: nil>
2.0.0-p451 :002 > a.title
=> "Rails"
2.0.0-p451 :004 > a.content
=> "Rails Post"
2.0.0-p451 :005 > a.inspect
=> "#<Post id: nil, title: nil, content: nil, author: nil, rating: nil, created_at: nil, updated_at: nil>"
2.0.0-p451 :006 > a.errors.messages
=> {}
2.0.0-p451 :007 > a.valid?
=> true
class Post < ActiveRecord::Base
attr_accessor :title, :content, :author, :rating
end
You are defining attr_accessor for all your properties, which is a shortcut for defining getters and setters for an instance variable of the same name like so:
def content
#content
end
def content=(new_content)
#content = new_content
end
Rails will also auto-generate you methods with these names, for every database field that your model has. These methods will conflict with each other.
When you call post.content = 'foo', instead of calling the Rails-generated method that will internally set your model's content attribute to 'foo', you're calling the attr_accessor-defined method which will set the instance variable #content to 'foo'.
The output of inspect is iterating over the Rails-defined model attributes, not the instance variables.
Did you actually mean to declare these attributes as attr_accessible instead of attr_accessor?
Related
I have class & subclass with one document looks like :
class Core::User
include Mongoid::Document
include Mongoid::Timestamps
store_in collection: 'users'
end
class Core::Moderator < Core::User
end
I tried to add a user from console
2.4.2 :002 > user = Core::User.new(email: 'email#domain.com', name: 'new user')
=> #<Core::User _id: BSON::ObjectId('5a015465fe37a86430b1e0ff'), created_at: nil, email: "email#domain.com", name: "new_user", updated_at: nil>
2.4.2 :003 > user.save
=> true
2.4.2 :004 > user._type
NoMethodError: undefined method `_type' for #<Core::User:0x0000000003e77ea0>
from (irb):4
And then add new moderator :
2.4.2 :005 > moderator = Core::Moderator.new(email: 'email2#domail.com', name: 'new moderator')
#<Core::Moderator _id: BSON::ObjectId('5a015600fe37a86430b1e100'), created_at: nil, email: "email2#domain.com", name: "new moderator", updated_at: nil>
2.4.2 :006 > moderator.save
=> true
2.4.2 :007 > moderator._type
=> "Core::Moderator"
Next add new user again :
2.4.2 :008 > user = Core::User.new(email: 'email3#domain.com', name: 'new user 2')
=> #<Core::User _id: BSON::ObjectId('5a015704fe37a86430b1e101'), created_at: nil, email: "email3#domain.com", name: "new user 2", updated_at: nil>
2.4.2 :009 > user.save
=> true
2.4.2 :010 > user._type
=> "Core::User"
Why I should create subclass first to get field _type on parent class? Every I start new console and create new user (Core::User) the field _type not generated.
I user Ruby 2.4.2, Rails 5.1.4, Mongoid 6.2.1
In order for inheritance to work as expected in Mongoid you need to set preload_models: true. Otherwise the model cannot know that it has subclasses.
# config/mongoid.yml
development:
# ...
options:
# ...
# Preload all models in development, needed when models use
# inheritance. (default: false)
preload_models: true
I'm trying to make a custom validator work on my app.
I have already configured my config.autoload.paths and it is loading fine.
The problem is with the validator itself.
Result of binding pry
instance variables: #attributes #options #with
locals: _ _dir_ _ex_ _file_ _in_ _out_ _pry_ attribute record value
[12] pry(#<FileCountValidator>)> value
=> [#<Attachment id: 60, description: nil, file: "cache_600_1__img_948867_5770137d84a6c79ac825886938e...", attachable_type: "Post", attachable_id: 15, created_at: "2012-03-10 14:50:54", updated_at: "2012-03-10 14:50:54">,
#<Attachment id: 61, description: nil, file: "cache_600_1__img_948867_90f64e01b9c871ec656a884e015...", attachable_type: "Post", attachable_id: 15, created_at: "2012-03-10 14:50:54", updated_at: "2012-03-10 14:50:54">,
#<Attachment id: 62, description: nil, file: "cache_600_1__img_948867_85eda3946c27fa90566403ac941...", attachable_type: "Post", attachable_id: 15, created_at: "2012-03-10 14:50:54", updated_at: "2012-03-10 14:50:54">,
#<Attachment id: nil, description: nil, file: nil, attachable_type: "Post", attachable_id: 15, created_at: nil, updated_at: nil>]
[13] pry(#<FileCountValidator>)> value > #with
TypeError: compared with non class/module
from /home/kleber/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.1/lib/active_record/relation/delegation.rb:20:in `>'
[14] pry(#<FileCountValidator>)> value.size > #with
=> true
[15] pry(#<FileCountValidator>)> value.size
=> 4
[16] pry(#<FileCountValidator>)> #with
=> 3
[17] pry(#<FileCountValidator>)>
So, I trying to make this comparisson exactly like I did on the pry debug console.
def validate_each(record, attribute, value)
#binding.pry
record.errors.add(attribute,"#{#with} attachments per post only. #{attribute['file'].size} detected.") if value.size > #with
end
But doing this, return me the error:
NoMethodError (undefined method `size' for nil:NilClass):
lib/validators/file_count_validator.rb:11:in `validate_each'
app/controllers/posts_controller.rb:61:in `block in update'
app/controllers/posts_controller.rb:60:in `update'
Are there any way to catch the value before it get enters the validate_each method?
Sorry, but the value being passed seems to be correct. value is meant to be the value of that attribute for that record, i.e. record.send(attribute) should be equal to the value.
Calling validates :attachments, :photo_count => 2 does not send 2 to the validate_each method as argument value. You could do :photo_count => true, which is what I generally do, or even :photo_count => "foo". The photo_count in your validates statement serves to provide that the validator is to be called by passing the value(i.e. 2 or true or "foo" for stated examples) embedded in the options hash.
Here's a way without passing a limit to the validator.
Create a Constants class and define MAX_ATTACHMENTS constant. I usually have it at models/constants.rb.
class Constants
MAX_ATTACHMENTS = 1
end
Then, in the validator, you could do
class PhotoCountValidator < ActiveModel::EachValidator
def validate_each(record, attribute, value)
record.errors.add(attribute,"#{Constants::MAX_ATTACHMENTS} attachments per post only.") if record.send(attribute).size > Constants::MAX_ATTACHMENTS
end
end
Another way that passes a parameter to a validator:
validates :attachments, :photo_count => 3 #desired_limit
Override the initialize method for PhotoCountValidator class, and initialize a class variable :
def initialize(options)
##max_objects = options[:with] # the options hash will be as {:attributes=>[:attachments], :with=>3}, where :with contains the desired limit passed
super
end
Then within the validate_each method :
record.errors.add(attribute,"#{##max_objects} attachments per post only.") if record.send(attribute).size > ##max_objects
I have just upgraded to rails 3.2.1.
I use the jQuery UI datepicker to set dates in rails text_fields. The field sets a date column in the database.
But, now it does not work.
I have this code in the view.
<%= p.text_field :due, :value => Time.now.strftime("%m/%d/%Y"), :id => "dialog_project_date" %>
If I don't change the date all goes well. If I change the date Rails puts nil in the database. This also happens when I disable jQuery datepicker and enter the date (with the right format) manually.
It seems to me that there is something with the way rails handles the formatting of the date field.
I can't find a solution. Does anybody have an idea?
Update
I used the debugger in the create action. Here's the otuput
(rdb:22) params
{"utf8"=>"✓", "authenticity_token"=>"4IChBeyKzkc4dwzje1RMPy2GBTMs5m2zrBPBFbIIKJw=", "project"=>{"name"=>"gunnaer", "description"=>"", "due"=>"03/17/2012", "customer_id"=>""}, "commit"=>"Save", "controller"=>"projects", "action"=>"create_index"}
(rdb:22) #project
#<Project id: nil, name: "gunnaer", description: "", due: nil, active: true, budget: nil, hour_price: nil, firm_id: 1, customer_id: nil, created_at: nil, updated_at: nil>
(rdb:22) #project.due = "03/17/2012"
"03/17/2012"
(rdb:22) #project
#<Project id: nil, name: "gunnaer", description: "", due: nil, active: true, budget: nil, hour_price: nil, firm_id: 1, customer_id: nil, created_at: nil, updated_at: nil>
The params is right, but the due param does not get set to the instans variable. The format is the same when I do not change the date. When I do not change it, it works.
Strange..
Your date format is wrong. Try using "yyyy/mm/dd"
This works:
ruby-1.9.2-p290 :002 > b = Blog.first
=> #<Blog id: 1, title: "Something", created_at: "2012-03-09 13:38:23", updated_at: "2012-03-09 13:38:32">
ruby-1.9.2-p290 :003 > b.created_at
=> Fri, 09 Mar 2012 13:38:23 UTC +00:00
ruby-1.9.2-p290 :004 > b.created_at = "2012/03/17"
=> "2012/03/17"
ruby-1.9.2-p290 :005 > b.save
=> true
ruby-1.9.2-p290 :006 > Blog.first
=> #<Blog id: 1, title: "Something", created_at: "2012-03-17 00:00:00", updated_at: "2012-03-09 13:58:55">
This does not:
ruby-1.9.2-p290 :007 > b.created_at = "03/17/2012"
=> "03/17/2012"
ruby-1.9.2-p290 :008 > b.save
=> true
ruby-1.9.2-p290 :009 > Blog.first
=> #<Blog id: 1, title: "Something", created_at: nil, updated_at: "2012-03-09 13:59:22">
EDIT
You have a few options for date format, which you should specify in your jquery ui code. See this link for examples - http://jqueryui.com/demos/datepicker/date-formats.html
To debug, first see what values are being POSTed to your controller. Either check the log or use a debugging proxy such as fiddle.
Then use the Rails console to isolate where the problem is happening.
UPDATED
The problem is that latest ver of Ruby (not Rails) assumes European date formats. A work-around to still use US format
I have the following model:
class Bill
. . . some fields . . .
belongs_to :sponsor, :class_name => "Legislator"
end
class Legislator
.. .some fields . . .
has_many :bills
end
I get this strange behavior, but I am sure this is something simple:
Loading development environment (Rails 3.0.7)
b = Bill.first
l = Legislator.first
l.bills << b
l.save
=> true
(I can view l.bills, but l.bills.all.to_a.count is 0)
l.govtrack_id
=> 400001
ruby-1.9.2-p180 :007 > Legislator.where(govtrack_id: 400001).first.bills
=> []
So I can create the association and view it. The save is successful, but when I retrieve the object, the association is gone . . . no errors. I'm confused, what am I missing?
You're missing inverse_of on your Legislator model. I ran a quick test (to make sure there wasn't a Mongoid issue). My models were thus:
class Bill
include Mongoid::Document
include Mongoid::Timestamps
field :name
belongs_to :sponsor, :class_name => "Legislator"
end
class Legislator
include Mongoid::Document
include Mongoid::Timestamps
field :govtrack_id
has_many :bills, :inverse_of => :sponsor
end
And console output from the test:
ruby-1.9.2-p180 > Bill.create(:name => "A new bill")
=> #<Bill _id: 4e0822636a4f1d11c1000001, _type: nil, created_at: 2011-06-27 06:25:39 UTC, updated_at: 2011-06-27 06:25:39 UTC, name: "A new bill", sponsor_id: nil>
ruby-1.9.2-p180 > Legislator.create(:govtrack_id => "400123")
=> #<Legislator _id: 4e0822786a4f1d11c1000002, _type: nil, created_at: 2011-06-27 06:26:00 UTC, updated_at: 2011-06-27 06:26:00 UTC, govtrack_id: "400123">
ruby-1.9.2-p180 > l = Legislator.first
ruby-1.9.2-p180 > l.bills << Bill.first
=> [#<Bill _id: 4e0822636a4f1d11c1000001, _type: nil, created_at: 2011-06-27 06:25:39 UTC, updated_at: 2011-06-27 06:26:08 UTC, name: "A new bill", sponsor_id: BSON::ObjectId('4e0822786a4f1d11c1000002')>]
ruby-1.9.2-p180 > l.save!
=> true
ruby-1.9.2-p180 > Bill.first.sponsor.govtrack_id
=> "400123"
ruby-1.9.2-p180 > Legislator.first.bills
=> [#<Bill _id: 4e0822636a4f1d11c1000001, _type: nil, created_at: 2011-06-27 06:25:39 UTC, updated_at: 2011-06-27 06:26:08 UTC, name: "A new bill", sponsor_id: BSON::ObjectId('4e0822786a4f1d11c1000002')>]
I've implemented a belongs_to relation with :counter_cache => true and I notice that the counter cache does not get updated if the relation was not set up before the initial save.
For instance, say a company has_many employees. If I do
company.employees << Employee.new(:name => "Joe")
The counter gets updated correctly but if I do
company.employees << Employee.create(:name => "Joe")
The counter remains unchanged.
For more details, here are the models:
class Employee < ActiveRecord::Base
belongs_to :company, :counter_cache => true
end
class Company < ActiveRecord::Base
has_many :employees
end
And here's a Rails Console session that demonstrates this:
Loading development environment (Rails 3.0.5)
ruby-1.9.2-p180 :001 > company_a = Company.create(:name => "ACME")
=> #<Company id: 1, name: "ACME", created_at: "2011-07-22 01:31:39", updated_at: "2011-07-22 01:31:39", employees_count: 0>
ruby-1.9.2-p180 :002 > company_a.employees << Employee.new(:name => "Bob")
=> [#<Employee id: 1, company_id: 1, name: "Bob", created_at: "2011-07-22 01:31:59", updated_at: "2011-07-22 01:31:59">]
ruby-1.9.2-p180 :003 > company_a.reload
=> #<Company id: 1, name: "ACME", created_at: "2011-07-22 01:31:39", updated_at: "2011-07-22 01:31:39", employees_count: 1>
ruby-1.9.2-p180 :004 > company_a.employees << Employee.create(:name => "Joe")
=> [#<Employee id: 1, company_id: 1, name: "Bob", created_at: "2011-07-22 01:31:59", updated_at: "2011-07-22 01:31:59">, #<Employee id: 2, company_id: 1, name: "Joe", created_at: "2011-07-22 01:32:28", updated_at: "2011-07-22 01:32:28">]
ruby-1.9.2-p180 :005 > company_a.reload
=> #<Company id: 1, name: "ACME", created_at: "2011-07-22 01:31:39", updated_at: "2011-07-22 01:31:39", employees_count: 1>
The documentation does say that the counter is incremented/decremented when the object is created/destroyed but I was thinking it should monitor updates as well to be useful. Otherwise, say, moving employees between companies would quickly result in counters that are totally off.
Is this the expected behavior? If so, what's the rationale? And if not, am I doing something wrong? I tried this in Rails 3.0.5 and Ruby 1.9.2
Thanks!