Class: ActiveRecord::Associations::CollectionProxy

Inherits:
Relation
  • Object
show all
Defined in:
lib/ocean-dynamo/active_record_stuff/collection_proxy.rb

Overview

Association proxies in OceanDynamo are middlemen between the object that holds the association, known as the @owner, and the actual associated object, known as the @target. The kind of association any proxy is about is available in @reflection. That’s an instance of the class OceanDynamo::Reflection::AssociationReflection.

For example, given

class Blog < OceanDynamo::Table
  has_many :posts
end

blog = Blog.first

the association proxy in blog.posts has the object in blog as @owner, the collection of its posts as @target, and the @reflection object represents a :has_many macro.

This class delegates unknown methods to @target via method_missing.

The @target object is not loaded until needed.

Constant Summary

Constants inherited from Relation

Relation::MULTI_VALUE_METHODS, Relation::SINGLE_VALUE_METHODS, Relation::VALUE_METHODS

Instance Attribute Summary

Attributes inherited from Relation

#default_scoped, #klass, #loaded, #table

Instance Method Summary collapse

Methods inherited from Relation

#as_json, #blank?, #eager_loading?, #explain, #find_or_create_by, #find_or_create_by!, #find_or_initialize_by, #first_or_create, #first_or_create!, #first_or_initialize, #initialize_copy, #insert, #inspect, #joined_includes_values, #load, #pretty_print, #reset, #scope_for_create, #to_sql, #uniq_value, #update, #update_all, #values, #where_values_hash, #with_default_scope

Constructor Details

#initialize(klass, association) ⇒ CollectionProxy

Returns a new instance of CollectionProxy.



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 30

def initialize(klass, association)
  @association = association
  super klass, klass.arel_table
  self.default_scoped = true
  merge! association.scope(nullify: false)
end

Instance Method Details

#<<(*records) ⇒ Object Also known as: push, append

Adds one or more records to the collection by setting their foreign keys to the association’s primary key. Returns self, so several appends may be chained together.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.size # => 0
person.pets << Pet.new(name: 'Fancy-Fancy')
person.pets << [Pet.new(name: 'Spook'), Pet.new(name: 'Choo-Choo')]
person.pets.size # => 3

person.id # => 1
person.pets
# => [
#      #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#      #<Pet id: 2, name: "Spook", person_id: 1>,
#      #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 947

def <<(*records)
  proxy_association.concat(records) && self
end

#==(other) ⇒ Object

Equivalent to Array#==. Returns true if the two arrays contain the same number of elements and if each element is equal to the corresponding element in the other array, otherwise returns false.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets
# => [
#      #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#      #<Pet id: 2, name: "Spook", person_id: 1>
#    ]

other = person.pets.to_ary

person.pets == other
# => true

other = [Pet.new(id: 1), Pet.new(id: 2)]

person.pets == other
# => false



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 885

def ==(other)
  load_target == other
end

#any?(&block) ⇒ Boolean

Returns true if the collection is not empty.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.count # => 0
person.pets.any?  # => false

person.pets << Pet.new(name: 'Snoop')
person.pets.count # => 0
person.pets.any?  # => true

You can also pass a block to define criteria. The behavior is the same, it returns true if the collection based on the criteria is not empty.

person.pets
# => [#<Pet name: "Snoop", group: "dogs">]

person.pets.any? do |pet|
  pet.group == 'cats'
end
# => false

person.pets.any? do |pet|
  pet.group == 'dogs'
end
# => true

Returns:

  • (Boolean) 


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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 783

def any?(&block)
  @association.any?(&block)
end

#build(attributes = {}, &block) ⇒ Object Also known as: new

Returns a new object of the collection type that has been instantiated with attributes and linked to this object, but have not yet been saved. You can pass an array of attributes hashes, this will return an array with the new objects.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.build
# => #<Pet id: nil, name: nil, person_id: 1>

person.pets.build(name: 'Fancy-Fancy')
# => #<Pet id: nil, name: "Fancy-Fancy", person_id: 1>

person.pets.build([{name: 'Spook'}, {name: 'Choo-Choo'}, {name: 'Brain'}])
# => [
#      #<Pet id: nil, name: "Spook", person_id: 1>,
#      #<Pet id: nil, name: "Choo-Choo", person_id: 1>,
#      #<Pet id: nil, name: "Brain", person_id: 1>
#    ]

person.pets.size  # => 5 # size of the collection
person.pets.count # => 0 # count from database



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 231

def build(attributes = {}, &block)
  @association.build(attributes, &block)
end

#clear ⇒ Object

Equivalent to delete_all. The difference is that returns self, instead of an array with the deleted objects, so methods can be chained. See delete_all for more information.



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 960

def clear
  delete_all
  self
end

#concat(*records) ⇒ Object

Add one or more records to the collection by setting their foreign keys to the association’s primary key. Since << flattens its argument list and inserts each record, push and concat behave identically. Returns self so method calls may be chained.

class Person < OceanDynamo::Table
  pets :has_many
end

person.pets.size # => 0
person.pets.concat(Pet.new(name: 'Fancy-Fancy'))
person.pets.concat(Pet.new(name: 'Spook'), Pet.new(name: 'Choo-Choo'))
person.pets.size # => 3

person.id # => 1
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.concat([Pet.new(name: 'Brain'), Pet.new(name: 'Benny')])
person.pets.size # => 5



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 306

def concat(*records)
  @association.concat(*records)
end

#count(column_name = nil, options = {}) ⇒ Object

Count all records using SQL.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.count # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 676

def count(column_name = nil, options = {})
  @association.count(column_name, options)
end

#create(attributes = {}, &block) ⇒ Object

Returns a new object of the collection type that has been instantiated with attributes, linked to this object and that has already been saved (if it passes the validations).

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.create(name: 'Fancy-Fancy')
# => #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>

person.pets.create([{name: 'Spook'}, {name: 'Choo-Choo'}])
# => [
#      #<Pet id: 2, name: "Spook", person_id: 1>,
#      #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.size  # => 3
person.pets.count # => 3

person.pets.find(1, 2, 3)
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 262

def create(attributes = {}, &block)
  @association.create(attributes, &block)
end

#create!(attributes = {}, &block) ⇒ Object

Like create, except that if the record is invalid, raises an exception.

class Person < OceanDynamo::Table
  has_many :pets
end

class Pet
  validates :name, presence: true
end

person.pets.create!(name: nil)
# => OceanDynamo::RecordInvalid: Validation failed: Name can't be blank



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 278

def create!(attributes = {}, &block)
  @association.create!(attributes, &block)
end

#delete(*records) ⇒ Object

Deletes the records supplied and removes them from the collection. For has_many associations, the deletion is done according to the strategy specified by the :dependent option. Returns an array with the deleted records.

If no :dependent option is given, then it will follow the default strategy. The default strategy is :nullify. This sets the foreign keys to NULL. For, has_many :through, the default strategy is delete_all.

class Person < OceanDynamo::Table
  has_many :pets # dependent: :nullify option by default
end

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.delete(Pet.find(1))
# => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>]

person.pets.size # => 2
person.pets
# => [
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

Pet.find(1)
# => #<Pet id: 1, name: "Fancy-Fancy", person_id: nil>

If it is set to :destroy all the records are removed by calling their destroy method. See destroy for more information.

class Person < OceanDynamo::Table
  has_many :pets, dependent: :destroy
end

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.delete(Pet.find(1), Pet.find(3))
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.size # => 1
person.pets
# => [#<Pet id: 2, name: "Spook", person_id: 1>]

Pet.find(1, 3)
# => OceanDynamo::RecordNotFound: Couldn't find all Pets with IDs (1, 3)

If it is set to :delete_all, all the records are deleted without calling their destroy method.

class Person < OceanDynamo::Table
  has_many :pets, dependent: :delete_all
end

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.delete(Pet.find(1))
# => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>]

person.pets.size # => 2
person.pets
# => [
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

Pet.find(1)
# => OceanDynamo::RecordNotFound: Couldn't find Pet with id=1

You can pass Fixnum or String values, it finds the records responding to the id and executes delete on them.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.delete("1")
# => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>]

person.pets.delete(2, 3)
# => [
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 568

def delete(*records)
  @association.delete(*records)
end

#delete_all ⇒ Object

Deletes all the records from the collection. For has_many associations, the deletion is done according to the strategy specified by the :dependent option. Returns an array with the deleted records.

If no :dependent option is given, then it will follow the default strategy. The default strategy is :nullify. This sets the foreign keys to NULL. For, has_many :through, the default strategy is delete_all.

class Person < OceanDynamo::Table
  has_many :pets # dependent: :nullify option by default
end

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.delete_all
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.size # => 0
person.pets      # => []

Pet.find(1, 2, 3)
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: nil>,
#       #<Pet id: 2, name: "Spook", person_id: nil>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: nil>
#    ]

If it is set to :destroy all the objects from the collection are removed by calling their destroy method. See destroy for more information.

class Person < OceanDynamo::Table
  has_many :pets, dependent: :destroy
end

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.delete_all
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

Pet.find(1, 2, 3)
# => OceanDynamo::RecordNotFound

If it is set to :delete_all, all the objects are deleted without calling their destroy method.

class Person < OceanDynamo::Table
  has_many :pets, dependent: :delete_all
end

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.delete_all
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

Pet.find(1, 2, 3)
# => OceanDynamo::RecordNotFound



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 424

def delete_all
  @association.delete_all
end

#destroy(*records) ⇒ Object

Destroys the records supplied and removes them from the collection. This method will always remove record from the database ignoring the :dependent option. Returns an array with the removed records.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.destroy(Pet.find(1))
# => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>]

person.pets.size # => 2
person.pets
# => [
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.destroy(Pet.find(2), Pet.find(3))
# => [
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.size  # => 0
person.pets       # => []

Pet.find(1, 2, 3) # => OceanDynamo::RecordNotFound: Couldn't find all Pets with IDs (1, 2, 3)

You can pass Fixnum or String values, it finds the records responding to the id and then deletes them from the database.

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 4, name: "Benny", person_id: 1>,
#       #<Pet id: 5, name: "Brain", person_id: 1>,
#       #<Pet id: 6, name: "Boss",  person_id: 1>
#    ]

person.pets.destroy("4")
# => #<Pet id: 4, name: "Benny", person_id: 1>

person.pets.size # => 2
person.pets
# => [
#       #<Pet id: 5, name: "Brain", person_id: 1>,
#       #<Pet id: 6, name: "Boss",  person_id: 1>
#    ]

person.pets.destroy(5, 6)
# => [
#       #<Pet id: 5, name: "Brain", person_id: 1>,
#       #<Pet id: 6, name: "Boss",  person_id: 1>
#    ]

person.pets.size  # => 0
person.pets       # => []

Pet.find(4, 5, 6) # => OceanDynamo::RecordNotFound: Couldn't find all Pets with IDs (4, 5, 6)



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 640

def destroy(*records)
  @association.destroy(*records)
end

#destroy_all ⇒ Object

Deletes the records of the collection directly from the database. This will always remove the records ignoring the :dependent option.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.size # => 3
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.destroy_all

person.pets.size # => 0
person.pets      # => []

Pet.find(1) # => Couldn't find Pet with id=1



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 450

def destroy_all
  @association.destroy_all
end

#distinct ⇒ Object Also known as: uniq

Specifies whether the records should be unique or not.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.select(:name)
# => [
#      #<Pet name: "Fancy-Fancy">,
#      #<Pet name: "Fancy-Fancy">
#    ]

person.pets.select(:name).distinct
# => [#<Pet name: "Fancy-Fancy">]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 658

def distinct
  @association.distinct
end

#empty? ⇒ Boolean

Returns true if the collection is empty. If the collection has been loaded or the :counter_sql option is provided, it is equivalent to collection.size.zero?. If the collection has not been loaded, it is equivalent to collection.exists?. If the collection has not already been loaded and you are going to fetch the records anyway it is better to check collection.length.zero?.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.count  # => 1
person.pets.empty? # => false

person.pets.delete_all

person.pets.count  # => 0
person.pets.empty? # => true

Returns:

  • (Boolean) 


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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 750

def empty?
  @association.empty?
end

#find(*args, &block) ⇒ Object

Finds an object in the collection responding to the id. Uses the same rules as OceanDynamo::Table.find. Returns OceanDynamo::RecordNotFound error if the object can not be found.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.find(1) # => #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>
person.pets.find(4) # => OceanDynamo::RecordNotFound: Couldn't find Pet with id=4

person.pets.find(2) { |pet| pet.name.downcase! }
# => #<Pet id: 2, name: "fancy-fancy", person_id: 1>

person.pets.find(2, 3)
# => [
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 143

def find(*args, &block)
  @association.find(*args, &block)
end

#first(*args) ⇒ Object

Returns the first record, or the first n records, from the collection. If the collection is empty, the first form returns nil, and the second form returns an empty array.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.first # => #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>

person.pets.first(2)
# => [
#      #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#      #<Pet id: 2, name: "Spook", person_id: 1>
#    ]

another_person_without.pets          # => []
another_person_without.pets.first    # => nil
another_person_without.pets.first(3) # => []



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 173

def first(*args)
  @association.first(*args)
end

#include?(record) ⇒ Boolean

Returns true if the given object is present in the collection.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets # => [#<Pet id: 20, name: "Snoop">]

person.pets.include?(Pet.find(20)) # => true
person.pets.include?(Pet.find(21)) # => false

Returns:

  • (Boolean) 


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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 835

def include?(record)
  @association.include?(record)
end

#last(*args) ⇒ Object

Returns the last record, or the last n records, from the collection. If the collection is empty, the first form returns nil, and the second form returns an empty array.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.last # => #<Pet id: 3, name: "Choo-Choo", person_id: 1>

person.pets.last(2)
# => [
#      #<Pet id: 2, name: "Spook", person_id: 1>,
#      #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

another_person_without.pets         # => []
another_person_without.pets.last    # => nil
another_person_without.pets.last(3) # => []



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 203

def last(*args)
  @association.last(*args)
end

#length ⇒ Object

Returns the size of the collection calling size on the target. If the collection has been already loaded, length and size are equivalent. If not and you are going to need the records anyway this method will take one less query. Otherwise size is more efficient.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.length # => 3
# executes something like SELECT "pets".* FROM "pets" WHERE "pets"."person_id" = 1

# Because the collection is loaded, you can
# call the collection with no additional queries:
person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 728

def length
  @association.length
end

#load_target ⇒ Object 



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 41

def load_target
  @association.load_target
end

#loaded? ⇒ Boolean

Returns true if the association has been loaded, otherwise false.

person.pets.loaded? # => false
person.pets
person.pets.loaded? # => true

Returns:

  • (Boolean) 


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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 53

def loaded?
  @association.loaded?
end

#many?(&block) ⇒ Boolean

Returns true if the collection has more than one record. Equivalent to collection.size > 1.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.count #=> 1
person.pets.many? #=> false

person.pets << Pet.new(name: 'Snoopy')
person.pets.count #=> 2
person.pets.many? #=> true

You can also pass a block to define criteria. The behavior is the same, it returns true if the collection based on the criteria has more than one record.

person.pets
# => [
#      #<Pet name: "Gorby", group: "cats">,
#      #<Pet name: "Puff", group: "cats">,
#      #<Pet name: "Snoop", group: "dogs">
#    ]

person.pets.many? do |pet|
  pet.group == 'dogs'
end
# => false

person.pets.many? do |pet|
  pet.group == 'cats'
end
# => true

Returns:

  • (Boolean) 


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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 821

def many?(&block)
  @association.many?(&block)
end

#prepend(*args) ⇒ Object

Raises:

  • (NoMethodError) 


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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 953

def prepend(*args)
  raise NoMethodError, "prepend on association is not defined. Please use << or append"
end

#proxy_association ⇒ Object 



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 839

def proxy_association
  @association
end

#reload ⇒ Object

Reloads the collection from the database. Returns self. Equivalent to collection(true).

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets # fetches pets from the database
# => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]

person.pets # uses the pets cache
# => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]

person.pets.reload # fetches pets from the database
# => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]

person.pets(true)  # fetches pets from the database
# => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 983

def reload
  proxy_association.reload
  self
end

#replace(other_array) ⇒ Object

Replaces this collection with other_array. This will perform a diff and delete/add only records that have changed.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets
# => [#<Pet id: 1, name: "Gorby", group: "cats", person_id: 1>]

other_pets = [Pet.new(name: 'Puff', group: 'celebrities']

person.pets.replace(other_pets)

person.pets
# => [#<Pet id: 2, name: "Puff", group: "celebrities", person_id: 1>]

If the supplied array has an incorrect association type, it raises an OceanDynamo::AssociationTypeMismatch error:

person.pets.replace(["doo", "ggie", "gaga"])
# => OceanDynamo::AssociationTypeMismatch: Pet expected, got String



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 332

def replace(other_array)
  @association.replace(other_array)
end

#scope ⇒ Object Also known as: spawn

Returns a Relation object for the records in this association



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 852

def scope
  @association.scope.tap do |scope|
    scope.proxy_association = @association
  end
end

#scoping ⇒ Object

We don’t want this object to be put on the scoping stack, because that could create an infinite loop where we call an @association method, which gets the current scope, which is this object, which delegates to @association, and so on.



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 847

def scoping
  @association.scope.scoping { yield }
end

#select(select = nil, &block) ⇒ Object

Works in two ways.

First: Specify a subset of fields to be selected from the result set.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.select(:name)
# => [
#      #<Pet id: nil, name: "Fancy-Fancy">,
#      #<Pet id: nil, name: "Spook">,
#      #<Pet id: nil, name: "Choo-Choo">
#    ]

person.pets.select([:id, :name])
# => [
#      #<Pet id: 1, name: "Fancy-Fancy">,
#      #<Pet id: 2, name: "Spook">,
#      #<Pet id: 3, name: "Choo-Choo">
#    ]

Be careful because this also means you’re initializing a model object with only the fields that you’ve selected. If you attempt to access a field that is not in the initialized record you’ll receive:

person.pets.select(:name).first.person_id
# => ActiveModel::MissingAttributeError: missing attribute: person_id

Second: You can pass a block so it can be used just like Array#select. This builds an array of objects from the database for the scope, converting them into an array and iterating through them using Array#select.

person.pets.select { |pet| pet.name =~ /oo/ }
# => [
#      #<Pet id: 2, name: "Spook", person_id: 1>,
#      #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.select(:name) { |pet| pet.name =~ /oo/ }
# => [
#      #<Pet id: 2, name: "Spook">,
#      #<Pet id: 3, name: "Choo-Choo">
#    ]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 113

def select(select = nil, &block)
  @association.select(select, &block)
end

#size ⇒ Object

Returns the size of the collection. If the collection hasn’t been loaded, it executes a SELECT COUNT(*) query. Else it calls collection.size.

If the collection has been already loaded size and length are equivalent. If not and you are going to need the records anyway length will take one less query. Otherwise size is more efficient.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets.size # => 3
# executes something like SELECT COUNT(*) FROM "pets" WHERE "pets"."person_id" = 1

person.pets # This will execute a SELECT * FROM query
# => [
#       #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
#       #<Pet id: 2, name: "Spook", person_id: 1>,
#       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#    ]

person.pets.size # => 3
# Because the collection is already loaded, this will behave like
# collection.size and no SQL count query is executed.



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 704

def size
  @association.size
end

#target ⇒ Object 



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 37

def target
  @association.target
end

#to_ary ⇒ Object Also known as: to_a

Returns a new array of objects from the collection. If the collection hasn’t been loaded, it fetches the records from the database.

class Person < OceanDynamo::Table
  has_many :pets
end

person.pets
# => [
#       #<Pet id: 4, name: "Benny", person_id: 1>,
#       #<Pet id: 5, name: "Brain", person_id: 1>,
#       #<Pet id: 6, name: "Boss",  person_id: 1>
#    ]

other_pets = person.pets.to_ary
# => [
#       #<Pet id: 4, name: "Benny", person_id: 1>,
#       #<Pet id: 5, name: "Brain", person_id: 1>,
#       #<Pet id: 6, name: "Boss",  person_id: 1>
#    ]

other_pets.replace([Pet.new(name: 'BooGoo')])

other_pets
# => [#<Pet id: nil, name: "BooGoo", person_id: 1>]

person.pets
# This is not affected by replace
# => [
#       #<Pet id: 4, name: "Benny", person_id: 1>,
#       #<Pet id: 5, name: "Brain", person_id: 1>,
#       #<Pet id: 6, name: "Boss",  person_id: 1>
#    ]



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# File 'lib/ocean-dynamo/active_record_stuff/collection_proxy.rb', line 922

def to_ary
  load_target.dup
end