Class: Mongoid::Fields::ForeignKey

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, `Standard`, Forwardable
Instance Chain: self, `Standard`
Inherits:	Mongoid::Fields::Standard `::Object` Mongoid::Fields::Standard Mongoid::Fields::ForeignKey
Defined in:	lib/mongoid/fields/foreign_key.rb

Overview

Represents a ::BSON document field definition which stores a foreign key that references the ID of another document. Used for association behavior.

Class Method Summary

`Standard` - Inherited

.new	Create the new field with a name and optional additional options.

Instance Attribute Summary

#foreign_key? ⇒ true | false readonly

Is this field a foreign key?
#lazy? ⇒ true | false readonly

Does this field do lazy default evaluation?
#object_id_field? ⇒ true | false readonly

Is the field a BSON::ObjectId?
#resizable? ⇒ true | false readonly

Returns true if an array, false if not.

`Standard` - Inherited

#default_val	Defines the behavior for defined fields in the document.
#foreign_key?	Is this field a foreign key?
#label	Defines the behavior for defined fields in the document.
#lazy?	Does this field do lazy default evaluation?
#localize_present?	Is the localized field enforcing values to be present?
#localized?	Is the field localized or not?
#name	Defines the behavior for defined fields in the document.
#object_id_field?	Is the field a BSON::ObjectId?
#options	Defines the behavior for defined fields in the document.
#pre_processed?	Does the field pre-process its default value?

Instance Method Summary

#add_atomic_changes(document, name, key, mods, new_elements, old_elements)

Adds the atomic changes for this type of resizable field.
#evolve(object) ⇒ Object

Evolve the object into an id compatible object.
#mongoize(object) ⇒ Object

Mongoize the object into the Mongo friendly value.
#evaluate_default_proc(_doc) ⇒ Object private

Evaluate the default proc.
#mongoize_foreign_key(object) ⇒ Object private

Convert the provided object to a Mongo-friendly foreign key.
#primary_key_field private
#related_id_field ⇒ Fields::Standard private Internal use only Internal use only

Get the id field of the association.
#serialize_default(object) ⇒ Object private Internal use only Internal use only

This is used when default values need to be serialized.

`Standard` - Inherited

#add_atomic_changes	Adds the atomic changes for this type of resizable field.
#association	Get the metadata for the field if its a foreign key.
#eval_default	Evaluate the default value and return it.
#type	Get the type of this field - inferred from the class name.
#default_name	Get the name of the default method for this field.
#define_default_method	Define the method for getting the default on the document.
#evaluate_default_proc	Evaluate the default proc.
#evaluated_default	Get the evaluated default.
#included?	Is the field included in the fields that were returned from the database? We can apply the default if:
#serialize_default	This is used when default values need to be serialized.

Constructor Details

This class inherits a constructor from Mongoid::Fields::Standard

Instance Attribute Details

#foreign_key? ⇒ `true` | `false` (readonly)

Is this field a foreign key?

Examples:

Is the field a foreign key?

field.foreign_key?

Returns:

(true | false) —

If the field is a foreign key.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 49


def foreign_key?
  true
end

#lazy? ⇒ `true` | `false` (readonly)

Does this field do lazy default evaluation?

Examples:

Is the field lazy?

field.lazy?

Returns:

(true | false) —

If the field is lazy.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 81


def lazy?
  type.resizable?
end

#object_id_field? ⇒ `true` | `false` (readonly)

Is the field a BSON::ObjectId?

Examples:

Is the field a BSON::ObjectId?

field.object_id_field?

Returns:

(true | false) —

If the field is a ::BSON::ObjectId.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 107


def object_id_field?
  @object_id_field ||=
    association.polymorphic? || association.klass.using_object_ids?
end

#resizable? ⇒ `true` | `false` (readonly)

Returns true if an array, false if not.

Examples:

Is the field resizable?

field.resizable?

Returns:

(true | false) —

If the field is resizable.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 118


def resizable?
  type.resizable?
end

Instance Method Details

#add_atomic_changes(document, name, key, mods, new_elements, old_elements)

Adds the atomic changes for this type of resizable field.

@todo: Refactor, big time.

Examples:

Add the atomic changes.

field.add_atomic_changes(doc, "key", {}, [], [])

Parameters:

document (Document) —

The document to add to.
name (String) —

The name of the field.
key (String) —

The atomic location of the field.
mods (Hash) —

The current modifications.
new_elements (Array) —

The new elements to add.
old_elements (Array) —

The old elements getting removed.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 22


def add_atomic_changes(document, name, key, mods, new_elements, old_elements)
  old = old_elements || []
  new = new_elements || []
  if new.length > old.length
    if new.first(old.length) == old
      document.atomic_array_add_to_sets[key] = new.drop(old.length)
    else
      mods[key] = document.attributes[name]
    end
  elsif new.length < old.length
    pulls = old - new
    if new == old - pulls
      document.atomic_array_pulls[key] = pulls
    else
      mods[key] = document.attributes[name]
    end
  elsif new != old
    mods[key] = document.attributes[name]
  end
end

#evaluate_default_proc(_doc) ⇒ Object (private)

Evaluate the default proc. In some cases we need to instance exec, in others we don’t.

Examples:

Eval the default proc.

field.evaluate_default_proc(band)

Parameters:

doc (Document) —

The document.

Returns:

(Object) —

The called proc.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 155


def evaluate_default_proc(_doc)
  serialize_default(default_val[])
end

#evolve(object) ⇒ Object

Evolve the object into an id compatible object.

Examples:

Evolve the object.

field.evolve(object)

Parameters:

object (Object) —

The object to evolve.

Returns:

(Object) —

The evolved object.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 61


def evolve(object)
  if object_id_field? || object.is_a?(Document)
    if association.polymorphic?
      association.convert_to_foreign_key(object)
    elsif object.is_a?(Document) && object.respond_to?(association.primary_key)
      primary_key_field.evolve(object.send(association.primary_key))
    else
      object.__evolve_object_id__
    end
  else
    related_id_field.evolve(object)
  end
end

#mongoize(object) ⇒ Object

Mongoize the object into the Mongo friendly value.

Examples:

Mongoize the object.

field.mongoize(object)

Parameters:

object (Object) —

The object to Mongoize.

Returns:

(Object) —

The mongoized object.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 93


def mongoize(object)
  if type.resizable? || object_id_field?
    mongoize_foreign_key(object)
  else
    related_id_field.mongoize(object)
  end
end

#mongoize_foreign_key(object) ⇒ Object (private)

Convert the provided object to a Mongo-friendly foreign key.

Examples:

Convert the object to a foreign key.

mongoize_foreign_key(object)

Parameters:

object (Object) —

The object to convert.

Returns:

(Object) —

The converted object.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 132


def mongoize_foreign_key(object)
  if [ Array, Set ].include?(type)
    object = object.to_a if type == Set || object.is_a?(Set)

    if object.resizable?
      object.blank? ? object : association.convert_to_foreign_key(object)
    else
      object.blank? ? [] : association.convert_to_foreign_key(Array(object))
    end
  elsif !(object.nil? || object == '')
    association.convert_to_foreign_key(object)
  end
end

#primary_key_field (private)

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 171


def primary_key_field
  @primary_key_field ||= association.klass.fields[association.primary_key]
end

#related_id_field ⇒ Fields::Standard (private)

This method is for internal use only.

Get the id field of the association.

Examples:

Get the related id field.

field.related_id_field

Returns:

(Fields::Standard) —

The field.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 167


def related_id_field
  @related_id_field ||= association.klass.fields['_id']
end

#serialize_default(object) ⇒ Object (private)

This method is for internal use only.

This is used when default values need to be serialized. Most of the time just return the object.

Examples:

Serialize the default value.

field.serialize_default(obj)

Parameters:

object (Object) —

The default.

Returns:

(Object) —

The serialized default.

[ GitHub ]

# File 'lib/mongoid/fields/foreign_key.rb', line 186


def serialize_default(object)
  object
end

Class: Mongoid::Fields::ForeignKey

Overview

Class Method Summary

Standard - Inherited

Instance Attribute Summary

Standard - Inherited

Instance Method Summary

Standard - Inherited

Constructor Details

Instance Attribute Details

#foreign_key? ⇒ true | false (readonly)

#lazy? ⇒ true | false (readonly)

#object_id_field? ⇒ true | false (readonly)

#resizable? ⇒ true | false (readonly)

Instance Method Details

#add_atomic_changes(document, name, key, mods, new_elements, old_elements)

#evaluate_default_proc(_doc) ⇒ Object (private)

#evolve(object) ⇒ Object

#mongoize(object) ⇒ Object

#mongoize_foreign_key(object) ⇒ Object (private)

#primary_key_field (private)

#related_id_field ⇒ Fields::Standard (private)

#serialize_default(object) ⇒ Object (private)

`Standard` - Inherited

`Standard` - Inherited

`Standard` - Inherited

#foreign_key? ⇒ `true` | `false` (readonly)

#lazy? ⇒ `true` | `false` (readonly)

#object_id_field? ⇒ `true` | `false` (readonly)

#resizable? ⇒ `true` | `false` (readonly)