This module provides validations for any Ruby class.
There are two primary ways to implement validations
1) Placing validation methods with properties as params in your class
require 'aequitas' class ProgrammingLanguage include Aequitas attr_accessor :name validates_presence_of :name end
2) (TODO) Using inferred validations on Virtus attributes, please see Aequitas::Inferred. Note that not all validations that are provided via validation methods, are also available as autovalidation options. If they are available, they're functionally equivalent though.
class ProgrammingLanguage include Virtus include Aequitas attribute :name, String, :required => true end
See Aequitas::Macros to learn about the complete collection of validation rules available.
Aequitas validations may be manually evaluated against a resource using the `#valid?` method, which will return true if the resource is valid, and false if it is invalid.
Working with Validation Errors
If an instance fails one or more validation rules, Aequitas::Violation instances will populate the Aequitas::ViolationSet object that is available through the #errors method.
my_account = Account.new(:name => "Jose") if my_account.valid? # my_account is valid and has been saved else my_account.errors.each do |e| puts e end end
See Aequitas::ViolationSet for all you can do with the #errors method.
Aequitas also provide a means of grouping your validations into contexts. This enables you to run different sets of validations when you need it. For example, an instance may require separate validation rules depending on its state: publishing, exporting, importing and so on.
Again, using our example for pure Ruby class validations:
class ProgrammingLanguage include Virtus include Aequitas attribute :name, String def ensure_allows_manual_memory_management # ... end def ensure_allows_optional_parentheses # ... end validates_presence_of :name validates_with_method :ensure_allows_optional_parentheses, :when => [:implementing_a_dsl] validates_with_method :ensure_allows_manual_memory_management, :when => [:doing_system_programming] end
ProgrammingLanguage instance now use #valid? method with one of two context symbols:
@ruby.valid?(:implementing_a_dsl) # => true @ruby.valid?(:doing_system_programming) # => false @c.valid?(:implementing_a_dsl) # => false @c.valid?(:doing_system_programming) # => true
Each context causes different set of validations to be triggered. If you don't specify a context using :when, :on or :group options (they are all aliases and do the same thing), default context name is :default. When you do model.valid? (without specifying context explicitly), again, :default context is used. One validation can be used in two, three or five contexts if you like:
class Book include Virtus include Aequitas attribute :id, Serial attribute :name, String attribute :agreed_title, String attribute :finished_toc, Boolean # used in all contexts, including default validates_presence_of :name, :when => [:default, :sending_to_print] validates_presence_of :agreed_title, :when => [:sending_to_print] validates_with_block :toc, :when => [:sending_to_print] do if self.finished_toc [true] else [false, "TOC must be finalized before you send a book to print"] end end end
In the example above, name is validated for presence in both :default context and :sending_to_print context, while TOC related block validation and title presence validation only take place in :sending_to_print context.