Rails Model Validation Best Practices (Full Guide) Your complete, professional, Rails-grade guide to Model Validation Best Practices

rails_validators.md

The Default Rails Validators:

             validates :attribute, validator_name: options

You can memorize the core validators in 10 seconds:

Validator	Purpose	Example
presence:	must not be blank	presence: true
absence:	must be blank	absence: true
confirmation:	requires a matching field	confirmation: true
acceptance:	typical checkbox	terms: acceptance: true
numericality:	must be number	numericality: true
length:	length constraints	length: { max: 100 }
inclusion:	value must be in list/range	inclusion: 1..5
exclusion:	must not be in list	exclusion: ["admin"]
format:	regex match	format: /@/

Rails maps the

validator_name to a validator class:

      presence: → PresenceValidator

       length: → LengthValidator

 numericality: → NumericalityValidator

       format: → FormatValidator

   custom ones → EmailValidator