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Diffstat (limited to 'activemodel/README.rdoc')
-rw-r--r-- | activemodel/README.rdoc | 53 |
1 files changed, 40 insertions, 13 deletions
diff --git a/activemodel/README.rdoc b/activemodel/README.rdoc index 9208145507..b4565b5881 100644 --- a/activemodel/README.rdoc +++ b/activemodel/README.rdoc @@ -9,10 +9,31 @@ Prior to Rails 3.0, if a plugin or gem developer wanted to have an object interact with Action Pack helpers, it was required to either copy chunks of code from Rails, or monkey patch entire helpers to make them handle objects that did not exactly conform to the Active Record interface. This would result -in code duplication and fragile applications that broke on upgrades. +in code duplication and fragile applications that broke on upgrades. Active +Model solves this by defining an explicit API. You can read more about the +API in ActiveModel::Lint::Tests. -Active Model solves this. You can include functionality from the following -modules: +Active Model provides a default module that implements the basic API required +to integrate with Action Pack out of the box: <tt>ActiveModel::Model</tt>. + + class Person + include ActiveModel::Model + + attr_accessor :name, :age + validates_presence_of :name + end + + person = Person.new(:name => 'bob', :age => '18') + person.name # => 'bob' + person.age # => '18' + person.valid? # => true + +It includes model name introspections, conversions, translations and +validations, resulting in a class suitable to be used with Action Pack. +See <tt>ActiveModel::Model</tt> for more examples. + +Active Model also provides the following functionality to have ORM-like +behavior out of the box: * Add attribute magic to objects @@ -20,7 +41,7 @@ modules: include ActiveModel::AttributeMethods attribute_method_prefix 'clear_' - define_attribute_methods [:name, :age] + define_attribute_methods :name, :age attr_accessor :name, :age @@ -50,7 +71,7 @@ modules: This generates +before_create+, +around_create+ and +after_create+ class methods that wrap your create method. - {Learn more}[link:classes/ActiveModel/CallBacks.html] + {Learn more}[link:classes/ActiveModel/Callbacks.html] * Tracking value changes @@ -87,18 +108,14 @@ modules: errors.add(:name, "can not be nil") if name.nil? end - def ErrorsPerson.human_attribute_name(attr, options = {}) + def self.human_attribute_name(attr, options = {}) "Name" end - end person.errors.full_messages # => ["Name can not be nil"] - person.errors.full_messages - # => ["Name can not be nil"] - {Learn more}[link:classes/ActiveModel/Errors.html] * Model name introspection @@ -118,6 +135,16 @@ modules: pattern in a Rails App and take advantage of all the standard observer functions. + class PersonObserver < ActiveModel::Observer + def after_create(person) + person.logger.info("New person added!") + end + + def after_destroy(person) + person.logger.warn("Person with an id of #{person.id} was destroyed!") + end + end + {Learn more}[link:classes/ActiveModel/Observer.html] * Making objects serializable @@ -163,7 +190,7 @@ modules: * Custom validators - class Person + class ValidatorPerson include ActiveModel::Validations validates_with HasNameValidator attr_accessor :name @@ -171,7 +198,7 @@ modules: class HasNameValidator < ActiveModel::Validator def validate(record) - record.errors[:name] = "must exist" if record.name.blank? + record.errors[:name] = "must exist" if record.name.blank? end end @@ -182,7 +209,7 @@ modules: p.valid? # => true {Learn more}[link:classes/ActiveModel/Validator.html] - + == Download and installation |