Custom form Validation Rails - ruby-on-rails

I am wondering if i have set up my method incorrectly as my validation attempt is being ignored halfway through the method. (i have provided a basic example, i want to get this working before adding more)
I have two variations of a form all belonging to the same object. The forms are differentiated by a column animal_type as you can see in my method
class Animal < ActiveRecord::Base
before_save :animal_form_validation
private
def animal_form_validation
if self.animal_type == 'Dog'
ap('Im validating the dog Form')
if self.name.length <= 0
errors.add(:name, "Name cannot be blank")
end
elsif self.animal_type == 'Cat'
ap('Im validating the cat form')
if self.name.length <= 0
errors.add(:name, "Name cannot be blank")
end
end
end
end
whether i am submitting a cat or dog i get the correct message in the console (using awesome print), so the method is running and knows which form im submitting, but as for the next if statement it is being ignored.
So i have an error with my syntax? or am i calling the wrong validation check on the name field ?
Thanks

Use validation instead of a before_save callback:
validate :animal_form_validation
Also, you can add conditional validation if you're checking the same condition prior to validating. Example: validate :animal_form_validation, if: name.blank?

You are calling those validation in before_save, which is after the record has been validated and is assumed to be valid. You need to run it as a validation:
validate :animal_form_validation

Related

How can I use a custom predicate to validate multiple fields with dry-validation?

I have an address form that I want to validate as a whole rather than validating each input on its own. I can only tell if the address is valid by passing the line1, city, state, zip to the custom predicate method so that it can check them as a unit.
How can I do this? I only see how to validate individual fields.
It seems that this "High-level Rules" example could help you :
schema = Dry::Validation.Schema do
required(:barcode).maybe(:str?)
required(:job_number).maybe(:int?)
required(:sample_number).maybe(:int?)
rule(barcode_only: [:barcode, :job_number, :sample_number]) do |barcode, job_num, sample_num|
barcode.filled? > (job_num.none? & sample_num.none?)
end
end
barcode_only checks 3 attributes at a time.
So your code could be :
rule(valid_address: [:line1, :city, :state, :zip]) do |line, city, state, zip|
# some boolean logic based on line, city, state and zip
end
Update—this is for ActiveRecords rather than dry-validation gem.
See this tutorial, http://guides.rubyonrails.org/active_record_validations.html
Quoting from the tutorial,
You can also create methods that verify the state of your models and add messages to the errors collection when they are invalid. You must then register these methods by using the validate (API) class method, passing in the symbols for the validation methods' names.
class Invoice < ApplicationRecord
validate :discount_cannot_be_greater_than_total_value
def discount_cannot_be_greater_than_total_value
if discount > total_value
errors.add(:discount, "can't be greater than total value")
end
end
end

Rails object.valid? with arguments

Is it possible to pass :symbols to the valid? method so that I can define if the object is valid up to a certain point?
Eg. if I have an object Person and want to call Person.valid?(:basic_info) and it will return true only if a certain subset of fields (say name & gender) are present?
I saw something that I thought might be of use but cannot get it working, it's conditional validations http://guides.rubyonrails.org/active_record_validations_callbacks.html#conditional-validation , in particular grouping conditional validations, but I couldn't get it working...
Can anyone help me out here please...
I don't think there already present like this however you can write a method on your own like following
def is_valid_field?(field)
self.valid?
self.errors[field].blank?
end
and then just person.is_valid_field?(:basic_info)
To validate basic_info you'll have to define a custom validator:
class Person < ActiveRecord::Base
validate :basic_info_present
def basic_info_present
if name.blank? || gender.blank?
errors.add(:basic_info, "can't be in blank")
end
end
end
If you then want to see if there are errors on the specific field, you can use #Salil's approach.
Note however that since there is no actual attribute called basic_info in your model, the validation errors here will not come up in forms, etc. (although they will be in the errors hash). That may or may not be what you want.
I got this to work using conditional validations, so now i can use .valid?(:basic) say for when i only want to check that the person has a name with the call...
validates_presence_of :name, :when => [:basic]
Documentation here: http://apidock.com/rails/ActiveRecord/Validations/valid%3F
This way I can have the object return true when calling .valid? even when it doesn't have a name, good times...

how to validate a record in table before saving in ruby on rails

I am new to Ruby on Rails
I have a scenario in which I have a form which has some fields. One of the field values I need to validate against a table which has the data .
I want to restrict the user from saving any data unless the field is validated with the table records.
Initially I added the code in controller to validate that but I have other fields which I need to validate as empty so it did not work .
Also I want the the validation error to be part of other errors.
I tried the below code in the model file
before_create :validate_company_id
def validate_company_id
cp = Company.find_by_company_id(self.company)
if #cp != nil
return
else
self.status ||= "Invalid"
end
end
But its not validating , could you help me how I can validate it .
regards
Surjan
The guys answered correctly, but provided the other way for solution. You could ask yourself: "Why doesn't my code get executed?"
First of all, you have errors in your code - #cp is undefined. Also, I don't know what are you trying to achieve with self.status ||= "Invalid".
You also don't have to use self when you're calling an attribute, but you do have to call it when you're assignig a new attribute value. So self.company is unnecessary, you can just use company.
I've also noticed you have the company_id attribute in your companies table. That's not neccessary, common convention is using just an id instead. If you don't want to alter your table you can set the id field on your model like so:
class Company < ActiveRecord::Base
set_primary_key :company_id
# ... the rest of your model code ...
end
After that you can use Company.find instead of Company.find_by_company_id.
Okay, let's say you have the following code after the fixes:
before_create :validate_company_id
def validate_company_id
cp = Company.find(company)
if cp != nil
return
else
self.status ||= "Invalid"
end
end
First of all I would like to use ternary operator here
before_create :validate_company_id
def validate_company_id
Company.find(company) ? return : self.status ||= "Invalid"
end
Isn't this cleaner? It does the exact same thing.
Now about that self.status of yours. If you would like to invalidate the object in ActiveModel you have to set some values in errors hash. You're in misconception if you think that a model with the status attribute of "Invalid" is invalid. It's still perfectly valid model in Rails.
So how do you invalidate?
You put some values into errors hash. You can also specify a message and the attribute you're validation error refers to.
So let's do it on your model
before_create :validate_company_id
def validate_company_id
Company.find(company) ? return : errors.add(:company,"Invalid Company ID")
end
Now if you try to save your model with invalid company_id it will still pass and get saved to the DB. Why is that?
It's because of the ActiveModels lifecycle. Your method gets called too late.
Here are all the callback methods you can use
Creating
before_validation
after_validation
before_save
around_save
before_create
around_create
after_create
after_save
Updating
before_validation
after_validation
before_save
around_save
before_update
around_update
after_update
after_save
Destroying
before_destroy
around_destroy
after_destroy
Notice how your method gets called long after the validation cycle. So you should not use before_create, but after_validation or before_validation callbacks instead.
And here we are with the working validation method of your model.
after_validation :validate_company_id
def validate_company_id
Company.find(company) ? return : errors.add(:company,"Invalid Company ID")
end
instead of using before_create. You can tell the model to use a custom method for validation as follows
validate :validate_company_id
def validate_company_id
cp = Company.find_by_company_id(self.company)
if cp.nil?
errors.add(:company, 'Invalid Company ID')
end
end
Inside you model, you can add custom validations as below:
validate :validate_company_id
def validate_company_id
Your validations
Add error messages can be added as below
errors.add(:company, "is invalid")
end

Activerecord field validation one after the other

I would like to know how do you validate a field after passing other validations, for example, I have:
validates_numericality_of :field
validates_inclusion_of :field (after validating field's numericality)
Thanks in advance.
You have to write a custom validation method for this.
This is how I would do it:
validate :custom_inclusion
private
def custom_inclusion
range = (1..100)
begin
Kernel.float(field)
rescue ArgumentError
errors.add(:field,"is not a number") and return
end
if !(range.min < field.to_i && range.max > field.to_i)
errors.add(:field,"is not between #{range.min} and #{range.max}")
end
end
where field is a model attribute you want to validate.

Validation rails one method for two fields

I have on my form two fields:
phone and mobile phone
I would like to use one method to validate two fields with one the same method how to do it??
Any validation can be used for any number of attributes. For example:
validates_presence_of :foo, :bar
If you're using a custom validation method, just make sure it inspects both attributes - something like this:
validate :phone_format
def phone_format
[phone, mobile].each do |attr|
errors.add(attr, "some error message") unless attr =~ /some regex/
end
end
Check out http://guides.rubyonrails.org/active_record_validations_callbacks.html
Write a custom validator

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