Module: ActiveModelPersistence::Persistence::ClassMethods

Defined in:
lib/active_model_persistence/persistence.rb

Overview

When this module is included in another class, ActiveSupport::Concern will make these class methods on that class.

Instance Method Summary collapse

Instance Method Details

#all ⇒ Array<Object>

Return all model objects that have been saved to the object store

Examples:

array_of_attributes = [
  { id: 1, name: 'James' },
  { id: 2, name: 'Frank' }
]
ModelExample.create(array_of_attributes)
ModelExample.all.count #=> 2
ModelExample.all.map(&:id) #=> [1, 2]
ModelExample.all.map(&:name) #=> ['James', 'Frank']



160
161
162
 
# File 'lib/active_model_persistence/persistence.rb', line 160

def all
  object_array.select { |object| object.is_a?(self) }.each
end

#count ⇒ Integer Also known as: size

The number of model objects saved in the object store

Examples:

array_of_attributes = [
  { id: 1, name: 'James' },
  { id: 2, name: 'Frank' }
]
ModelExample.create(array_of_attributes)
ModelExample.all.count #=> 2



176
177
178
 
# File 'lib/active_model_persistence/persistence.rb', line 176

def count
  object_array.select { |object| object.is_a?(self) }.size
end

#create(attributes = nil, &block) ⇒ Object+

Creates a new model object in to the object store and returns it

Create a new model object passing attributes and block to .new and then calls #save.

The new model object is returned even if it could not be saved to the object store.

Examples:

m = ModelExample.new(id: 1, name: 'James')
m.id #=> 1
m.name #=> 'James'

Multiple model objects can be created

array_of_attributes = [
  { id: 1, name: 'James' },
  { id: 2, name: 'Frank' }
]
objects = ModelExample.create(array_of_attributes)
objects.class #=> Array
objects.size #=> 2
objects.first.id #=> 1
objects.map(&:name) #=> ['James', 'Frank']



94
95
96
97
98
99
100
 
# File 'lib/active_model_persistence/persistence.rb', line 94

def create(attributes = nil, &block)
  if attributes.is_a?(Array)
    attributes.collect { |attr| create(attr, &block) }
  else
    new(attributes, &block).tap(&:save)
  end
end

#create!(attributes = nil, &block) ⇒ Object+

Creates a new model object in to the object store

Raises an error if the object could not be created.

Create a new model object passing attributes and block to .new and then calls #save!.

Examples:

m = ModelExample.new(id: 1, name: 'James')
m.id #=> 1
m.name #=> 'James'

Multiple model objects can be created

array_of_attributes = [
  { id: 1, name: 'James' },
  { id: 2, name: 'Frank' }
]
objects = ModelExample.create(array_of_attributes)
objects.class #=> Array
objects.size #=> 2
objects.first.id #=> 1
objects.map(&:name) #=> ['James', 'Frank']

Raises:

  • (ModelError) —

    if the model object could not be created



138
139
140
141
142
143
144
 
# File 'lib/active_model_persistence/persistence.rb', line 138

def create!(attributes = nil, &block)
  if attributes.is_a?(Array)
    attributes.collect { |attr| create!(attr, &block) }
  else
    new(attributes, &block).tap(&:save!)
  end
end

#destroy_all ⇒ void Also known as: delete_all

This method returns an undefined value.

Removes all model objects from the object store

Each saved model object’s #destroy method is called.

Examples:

array_of_attributes = [
  { id: 1, name: 'James' },
  { id: 2, name: 'Frank' }
]
ModelExample.create(array_of_attributes)
ModelExample.all.count #=> 2
ModelExample.destroy_all
ModelExample.all.count #=> 0



198
199
200
201
 
# File 'lib/active_model_persistence/persistence.rb', line 198

def destroy_all
  objects_to_destroy = object_array.select { |object| object.is_a?(self) }
  objects_to_destroy.each(&:destroy)
end