How would I validate the last letters of a link which is posted into my model?
Example:
[dropbox.com/dajnkqjknw7/file.mp3]
[dropbox.com/dajnkqjknw7/file.ogg]
[dropbox.com/dajnkqjknw7/file.wav]
I just want to check/validate if the last 3 (or 4) letters end on .mp3, .ogg or .wav, how would I use that within my model, use a Regex in combination with validates?
Current beat.rb model:
class Beat < ApplicationRecord
validates :bpm, format: { with: /\A\d+\z/ }, length: { maximum: 3 }
validates :link, presence: true REGEX IN HERE?
end
You can use something like this
validates :link, presence: true, format: { with: /.(mp3|ogv|wav)\z/}
where you have a dot . and after one of the valid extensions (mp3|ogv|wav), just at the end of the line \z
Related
I have the following model in Rails which manages a Diabetes Settings table:
class DiabetesSetting < ApplicationRecord
belongs_to :user
validates :bs_min, :bs_max, :bs_target, :correction_number, numericality: { only_integer: true }
validates :correction_insulin, numericality: true
validates :bs_min {less_than: :bs_max }
validates :bs_max {greater_than: :bs_min}
validates :bs_target {less_than: :bs_max}
end
My Question: Is something like this, to compare the fields of a database with each other to validate, that when a new setting is created, one value is higher or lower than the other, possible in Rails or do I have to write custom validation methods for this?
To clarify: bs_min is the mimmum value of a numerical range and bs_max the max value of a numerical range. They are both attributes inside the diabetes settings model.
The Question is if I can compare these values like I did or if I have to write custom methods to validate
Thanks in advance for Your help
You can do it using Rail's built-in validations. Try below code:
class DiabetesSetting < ApplicationRecord
...
validates_numericality_of :bs_min, { less_than: :bs_max }
validates_numericality_of :bs_max, { greater_than: :bs_min }
validates_numericality_of :bs_target, { less_than: :bs_max }
end
Refer to following link for numerical validation: http://api.rubyonrails.org/classes/ActiveModel/Validations/HelperMethods.html#method-i-validates_numericality_of
Ruby on Rails 7.0 added support for validates_comparison_of validations like this
validates :bs_min, comparison: { less_than: :bs_max }
validates :bs_max, comparison: { greater_than: :bs_min }
validates :bs_target, comparison: { less_than: :bs_max }
lets say that I want to make the possibility of posting two types of posts [long] and [short] sharing the same table [id, title, content, short:boolean, user_id] and model
and the user chose to post short post and the site only will store the content and it will be under 120 char, to recognize it we will put the short:true, but how to customize the validations if it chose short to allow empty title and content under 120 char ..... etc
Simplest way to solve your problem is conditional validations. Your model should be like this:
class Post < ActiveRecord::Base
validates :title, presence: true, unless: :short?
validates :title, absence: true, if: :short?
validates :content, presence: true
validates :content, length: { maximum: 120 }, if: :short?
end
I'm not sure i understood all conditions in your example right, hope this code is enough to make what you want.
Also you may read details about conditional validations in Rails documentation.
Since you have a short boolean field on Post, you can simply add these helper methods
class Post < AR
# this method is automatically generated by rails
def short?
short
end
def long?
!short
end
end
And then add if: or unless: to your validations:
validates :content, length: { maximum: 120 }, if: :short?
validates :content, presence: true, if: :long?
In my rails application, I have bank_details table with columns - account_number, ifsc_code, bank_name and branch_code(Only for India). But I don't know how to validates this columns before save it to database.Plese help me in this.
I will appreciate your help.
Thanks in advance.
In your model, you need to add a validates: your_column.
For example if you want to make sure that account number is present before you save to the database, you need to add validates: account_number, presence: true
There are both pre-built helpers, so you can validate by presence, name, etc, but you can also use a custom method to validate those.
Check out RailsGuides for all the details
There are so many validation that you can apply on your columns, here is a list of possible validation. you can pick as your requirement.
Validation for data should be present
validates :account_number, :ifsc_code, :branch_code, :bank_name, presence: true
data should be positive numbers only
validates :account_number, :branch_code, :numericality => { :greater_than_or_equal_to => 0 }
set length of record
validates :ifsc_code, length: { is: 11 }
validates that the attribute's value is unique right before the object gets saved
validates :account_number, uniqueness: true
In your model you can have something like this:
validates: branch_code
which is a standard validation, making sure its present
Or you can do more validation using regex
validates :bank_name, format: { with: /\A[a-zA-Z]+\z/,
message: "only allows letters" }
Here are some examples of validation:
validates :bank_name, length: { minimum: 2 }
validates :bank_name, length: { maximum: 500 }
validates :bank_name, length: { in: 6..20 }
validates :bank_name, length: { is: 6 }
Or use some advance techniques like so:
validates :bank_name, presence: true, if: "branch_code.nil?"
TransferWise provides an API you can use to validate IFSC codes and Indian account numbers:
IFSC code
https://api.transferwise.com/v1/validators/ifsc-code?ifscCode=YESB0236041
Account number
https://api.transferwise.com/v1/validators/indian-account-number?accountNumber=678911234567891
Documentation here.
I don't know why, but I am stuck with a simple issue. I have a simple User model and I have given a simple validation to one of its field ie., username for presence and its length.
Below is the code:
user.rb
class User < ActiveRecord::Base
validates :username, presence: true, length: { minumum: 3, maximum: 25 }
end
Accordingly,
user = User.new(username: 'hi')
user.save
must fail as the length of the username (i.e., is too short as per the validation given). But in my case it is getting saved without any errors. Currently it is only giving errors when username is blank but not giving errors for min length. Note: I have reload! my rails console
You have misspelled minimum :) Try this:
class User < ActiveRecord::Base
validates :username, presence: true, length: { minimum: 3, maximum: 25 }
end
Also, re: the answer below, this is directly from the RailsGuides for Active Record Validations:
class Essay < ActiveRecord::Base
validates :content, length: {
minimum: 300,
maximum: 400,
tokenizer: lambda { |str| str.split(/\s+/) },
too_short: "must have at least %{count} words",
too_long: "must have at most %{count} words"
}
end
I want to validate that a user name has no white/blank spaces for my Users. Is there a built in validation that does this? Or what is the best way to do this. Seems like it would be a pretty common requirement.
I would try format validator:
validates :username, format: { with: /\A[a-zA-Z0-9]+\Z/ }
as most of the time when you don't want whitespaces in username you also don't want other characters.
Or when you really only need to check for whitespace, use without instead:
validates :username, format: { without: /\s/ }
Full documentation: http://api.rubyonrails.org/classes/ActiveModel/Validations/HelperMethods.html#method-i-validates_format_of (validates ... format: {} is the same as validates_format_of ...)
I believe you will have to create a custom validator:
validate :check_empty_space
def check_empty_space
if self.attribute.match(/\s+/)
errors.add(:attribute, "No empty spaces please :(")
end
end
In your User model add validation. validates :username, format: { without: /\s/ } will remove white/blank spaces for your Users. You can even add a message alerting the user that their username contains whitespace.
class User < ActiveRecord::Base
validates :username, format: { without: /\s/, message: "must contain no spaces" }
end
You can use before_validation callback to strip whitespace
class User
before_validation :strip_blanks
protected
def strip_blanks
self.username = self.username.strip
end
end
MurifoX's answer is better, but regarding it being a common requirement, i think this is more often used:
validates :presence
class User < ActiveRecord::Base
validates :name, presence: true
end