Class: Mongoid::Fields::ForeignKey

Inherits:
Standard
  • Object
show all
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.

Instance Attribute Summary

Attributes inherited from Standard

#default_val, #label, #name, #options

Instance Method Summary collapse

Methods inherited from Standard

#association, #eval_default, #initialize, #localize_present?, #localized?, #pre_processed?, #type

Constructor Details

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

Instance Method Details

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

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.



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# File 'lib/mongoid/fields/foreign_key.rb', line 25

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

#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.



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# File 'lib/mongoid/fields/foreign_key.rb', line 64

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

#foreign_key? ⇒ true | false

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.



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# File 'lib/mongoid/fields/foreign_key.rb', line 52

def foreign_key?
  true
end

#lazy? ⇒ true | false

Does this field do lazy default evaluation?

Examples:

Is the field lazy?

field.lazy?

Returns:

  • (true | false) —

    If the field is lazy.



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# File 'lib/mongoid/fields/foreign_key.rb', line 84

def lazy?
  type.resizable?
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.



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# File 'lib/mongoid/fields/foreign_key.rb', line 96

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

#object_id_field? ⇒ true | false

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.



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# File 'lib/mongoid/fields/foreign_key.rb', line 110

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

#resizable? ⇒ true | false

Returns true if an array, false if not.

Examples:

Is the field resizable?

field.resizable?

Returns:

  • (true | false) —

    If the field is resizable.



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# File 'lib/mongoid/fields/foreign_key.rb', line 121

def resizable?
  type.resizable?
end