I would like to know if there's a way to use rails validations on a custom action.
For example I would like do something like this:
validates_presence_of :description, :on => :publish, :message => "can't be blank"
I do basic validations create and save, but there are a great many things I don't want to require up front. Ie, they should be able to save a barebones record without validating all the fields, however I have a custom "publish" action and state in my controller and model that when used should validate to make sure the record is 100%
The above example didn't work, any ideas?
UPDATE:
My state machine looks like this:
include ActiveRecord::Transitions
state_machine do
state :draft
state :active
state :offline
event :publish do
transitions :to => :active, :from => :draft, :on_transition => :do_submit_to_user, :guard => :validates_a_lot?
end
end
I found that I can add guards, but still I'd like to be able to use rails validations instead of doing it all on a custom method.
That looks more like business logic rather than model validation to me. I was in a project a few years ago in which we had to publish articles, and lots of the business rules were enforced just at that moment.
I would suggest you to do something like Model.publish() and that method should enforce all the business rules in order for the item to be published.
One option is to run a custom validation method, but you might need to add some fields to your model. Here's an example - I'll assume that you Model is called article
Class Article < ActiveRecord::Base
validate :ready_to_publish
def publish
self.published = true
//and anything else you need to do in order to mark an article as published
end
private
def ready_to_publish
if( published? )
//checks that all fields are set
errors.add(:description, "enter a description") if self.description.blank?
end
end
end
In this example, the client code should call an_article.publish and when article.save is invoked it will do the rest automatically. The other big benefit of this approach is that your model will always be consistent, rather than depending on which action was invoked.
If your 'publish' action sets some kind of status field to 'published' then you could do:
validates_presence_of :description, :if => Proc.new { |a| a.state == 'published' }
or, if each state has its own method
validates_presence_of :description, :if => Proc.new { |a| a.published? }
Related
What is the best way to adjust your validation of a model based on a parameter or action? Say I am entering a lead into a system, so all that is required is basic contact info. But then later I may enter a new contract for that user at which point I need more detailed information. So I may need phone number when just entering a lead but once they are entering into a contract I might need their birthdate and alternate phone number.
I considered using a state machine but the user could actually enter into two contracts at the same time so state doesn't really work for this scenario.
I also considered storing the extra info with the contract but since the user can have more than one contract, it needs to live with the user so it is not redundant.
So basically when saving a contract, it would tell me that the attached user is invalid if said user doesn't have the extra fields.
Check out conditional validations:
class Person
validates_presence_of :given_name, family_name
validates_presence_of :phone_number, :email_address, :if => :registered
with_options :if => :registered do |person|
# validations in this block are scoped to a registered user
person.validates_presence_of :dob
end
end
The :if option can take:
a symbol that corresponds to a method on the class that evaluates to true or false
a proc or lambda that returns a value that evaluates to true or false
a string containing ruby code (god knows why you'd want to do that)
You also have access to an :unless option which works in a similar fashion.
You can also encapsulate the logic to determine the current state of the user and use that to determine what validation steps you can take:
class Person
validates_presence_of :email_address, :if => ->(p) { p.state == :pending_confirmation }
# I actually prefer validations in this format
validate do # stricter validations when user is confirming registration
if confirming_membership && (given_name.blank? || family_name.blank?
errors.add(:base, 'A full name is required')
end
end
def state
# your logic could be anything, this is just an example
if self.confirmed_email
:registered
elsif confirming_membership
:pending_confirmation
else
:new_user
end
end
def confirming_membership
# some logic
end
end
You can use conditional validation for example:
validates_presence_of :phone, :if => Proc.new { |p| p.lead? }
In whatever action the lead posts to, you could just do this:
#object.save(validate: false)
Then, when they need to enter the contract, leave off that validate: false option to ensure that those validations run.
Also, see this post if you want to skip only certain validations.
I am using Ruby on Rails 3.0.7 and I would like to find some records at run time for validation purposes but passing\setting a value for that finder method. That is, in a my class I have the following:
class Group < < ActiveRecord::Base
validates :relation_id,
:presence => true,
:inclusion => {
:in => ... # Read below for more information about
}
end
If I set :in to be
:in => User.find(1).group_ids
it works, but I would like to set "some-dynamic-things" for the finder method instead of the 1 value stated below in the example. That is, I would like to do something like the following in order to pass to the model a <test_value> in someway:
class Group < < ActiveRecord::Base
validates :relation_id,
:presence => true,
:inclusion => {
:in => User.find(<test_value>).group_ids
}
end
Is it possible? If so, how can I pass the value to the constant?
P.S.: Just to know, I am trying to make that in order to move some logic from the controller to the model.
I'm inferring that what you're trying to do is enforce something like "Only users who are members of a group can save it." If that's the case, you have behavior that should stay in the controller.
Your model doesn't have access to the current session, and adding this logic will prevent you from using your model for other things in the future. For example, you'd never be able to save a group from a batch or maintenance job that wasn't associated with a user.
If you really want to do this you could put a current_user class level variable in the User object and set it in a before_filter...
class ApplicationController
before_fitler :set_current_user
def set_current_user
User.current_user = #however you get your user in your controllers
end
end
class User
##current_user
end
class Group
validates :user_in_group
def user_in_group
return true unless User.current_user #if we don't have a user set, skip validation
User.current_user.group_ids.include? self.id
end
end
It looks like you want something like a proc to be run for the validator for the :in attribute. I think you may be threading in dangerous territory when you rely on load order of models and playing with "dynamic constants".
Instead how about just building your own custom validator for this case?
It's not that hard, and you will have full control of what you need:
http://guides.rubyonrails.org/active_record_validations_callbacks.html#creating-custom-validation-methods
I need to validate a model only for a certain action (:create). I know this is not a good tactic, but i just need to do this in my case.
I tried using something like :
validate :check_gold, :if => :create
or
validate :check_gold, :on => :create
But i get errors. The problem is that i cannot have my custom check_gold validation execute on edit, but only on create (since checking gold has to be done, only when alliance is created, not edited).
Thanx for reading :)
I'm appending some actual code :
attr_accessor :required_gold, :has_alliance
validate :check_gold
validate :check_has_alliance
This is the Alliance model. :required_gold and :has_alliance are both set in the controller(they are virtual attributes, because i need info from the controller). Now, the actual validators are:
def check_gold
self.errors.add(:you_need, "100 gold to create your alliance!") if required_gold < GOLD_NEEDED_TO_CREATE_ALLIANCE
end
def check_has_alliance
self.errors.add(:you_already, "have an alliance and you cannot create another one !") if has_alliance == true
end
This works great for create, but i want to restrict it to create alone and not edit or the other actions of the scaffold.
All ActiveRecord validators have a :on option.
validates_numericality_of :value, :on => :create
Use the validate_on_create callback instead of validate:
validate_on_create :check_gold
validate_on_create :check_has_alliance
Edit:
If you use validates_each you can use the standard options available for a validator declaration.
validates_each :required_gold, :has_alliance, :on => :create do |r, attr, value|
r.check_gold if attr == :required_gold
r.check_has_alliance if attr == :has_alliance
end
Like Sam said, you need a before_create callback. Callbacks basically mean 'execute this method whenever this action is triggered'. (More about callbacks here : http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html).
This is what you want in your model:
before_create :check_gold
# other methods go here
private # validations don't need to be called outside the model
def check_gold
# do your validation magic here
end
The above method is the simplest to do what you want, but FYI there's also a way to use a before_save callback to execute additional actions on creation:
before_save :check_gold_levels
# other methods
private
def check_gold_levels
initialize_gold_level if new? # this will be done only on creation (i.e. if this model's instance hasn't been persisted in the database yet)
verify_gold_level # this happens on every save
end
For more info on 'new?' see http://api.rubyonrails.org/classes/ActiveResource/Base.html#method-i-new%3F
You need to look into callbacks. Someone once told me this and I didn't understand what they meant. Just do a search for rails callbacks and you will get the picture.
In your model you need to do a callback. The callback you need is before_create and then before a object is created you will be able to do some logic for check for errors.
model.rb
before_create :check_gold_validation
def check_gold_validation
validate :check_gold
end
def check_gold
errors.add_to_base "Some Error" if self.some_condition?
end
I am running into an issue when trying to apply an :if condition to a validates_associated validation. The if condition works for validates_presence_of, but not for validates_associated, and the form (with two models in it) works correctly, except that the validation still returns an error, regardless of whether the if condition is true or false.
validates_associated :departures, :if => :cruise?
validates_presence_of :ship_name, :if => :cruise?
def cruise?
item_marker == 1
end
# I even tested it using this, and it still returned a validated_associated error
def cruise?
false
end
#form item
<%= departure_form.date_select :date, :index => (departure.new_record? ? '' :
departure.id), :start_year =>Time.now.year, :order => [:month, :day, :year ],
:prompt=>true %>
I am using a date select for the :departures field, with a prompt for the for default values (i.e. the first selected option for each field with have a value=""). I believe this is what is causing the problem. I could remove the prompt and just blank out the departure dates for non_cruises in the controller, but that seems sloppy. does anyone have a suggestions? Note, this code uses portions of Ryan Bates's "Handle Multiple Models in One Form" Recipe.
I figured out what was wrong. My new departures builder function was creating departure objects for all items, whether they were cruises or not. I added an if cruises? statement to the code below and now it works properly.
has_many :departures, :dependent => :destroy
def new_departure_attributes=(departure_attributes)
departure_attributes.each do |attributes|
if cruises? #new if statement
departures.build(attributes)
end
end
end
#the following two methods are only used for update actions
#(the error happens in new/create as well)
def existing_departure_attributes=(departure_attributes)
departures.reject(&:new_record?).each do |departure|
attributes = departure_attributes[departure.id.to_s]
if attributes
departure.attributes = attributes
else
departures.delete(departure)
end
end
end
def save_departures
departures.each do |departure|
departure.save(false)
end
end
I have a rails model that validates uniqueness of 2 form values. If these 2 values aren't unique the validation errors are shows and the "submit" button is changed to "resubmit". I want to allow a user to click the "resubmit" button and bypass the model validation. I want to do something like this from the rails validation documentation:
validates_uniqueness_of :value, :unless => Proc.new { |user| user.signup_step <= 2 }
but I don't have a a value in my model that I can check for...just the params that have the "Resubmit" value.
Any ideas on how to do this?
In my opinion this is the best way to do it:
class FooBar < ActiveRecord::Base
validates_uniqueness_of :foo, :bar, :unless => :force_submit
attr_accessor :force_submit
end
then in your view, make sure you name the submit tag like
<%= submit_tag 'Resubmit', :name => 'foo_bar[force_submit]' %>
this way, all the logic is in the model, controller code will stay the same.
Try this:
Rails 2: Model.save(false)
Rails 3: Model.save(:validate => false)
It bypasses validations (all of them though).
Not positive about this, but you could try to add an attr_accessor to your model to hold whether or not the form has been submited once before.
just add
attr_accessor :submitted
to your model and check for it in your validations.
You can just look at the submit button to determine whether you want to perform the validations.
def form_method
case params[:submit]
when "Submit"
'Do your validation here'
when "Resubmit"
'Do not call validation routine'
end
end