Module: Mongoid::Traversable

Extended by:
ActiveSupport::Concern
Included in:
Composable
Defined in:
lib/mongoid/traversable.rb

Overview

Provides behaviour around traversing the document graph.

Since:

  • 4.0.0

Defined Under Namespace

Modules: ClassMethods

Instance Method Summary collapse

Instance Method Details

#_children ⇒ Array<Document>

Get all child Documents to this Document, going n levels deep if necessary. This is used when calling update persistence operations from the root document, where changes in the entire tree need to be determined. Note that persistence from the embedded documents will always be preferred, since they are optimized calls… This operation can get expensive in domains with large hierarchies.

Examples:

Get all the document’s children.

person._children

Returns:

  • (Array<Document>) —

    All child documents in the hierarchy.

Since:

  • 4.0.0



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# File 'lib/mongoid/traversable.rb', line 25

def _children
  @_children ||= collect_children
end

#_root ⇒ Document

Return the root document in the object graph. If the current document is the root object in the graph it will return self.

Examples:

Get the root document in the hierarchy.

document._root

Returns:

  • (Document) —

    The root document in the hierarchy.

Since:

  • 4.0.0



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# File 'lib/mongoid/traversable.rb', line 132

def _root
  object = self
  while (object._parent) do object = object._parent; end
  object || self
end

#_root? ⇒ true, false

Is this document the root document of the hierarchy?

Examples:

Is the document the root?

document._root?

Returns:

  • (true, false) —

    If the document is the root.

Since:

  • 3.1.0



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# File 'lib/mongoid/traversable.rb', line 146

def _root?
  _parent ? false : true
end

#collect_children ⇒ Array<Document>

Collect all the children of this document.

Examples:

Collect all the children.

document.collect_children

Returns:

Since:

  • 2.4.0



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# File 'lib/mongoid/traversable.rb', line 37

def collect_children
  children = []
  embedded_relations.each_pair do |name, metadata|
    without_autobuild do
      child = send(name)
      Array.wrap(child).each do |doc|
        children.push(doc)
        children.concat(doc._children)
      end if child
    end
  end
  children
end

#flag_children_persisted ⇒ Array<Document>

Marks all children as being persisted.

Examples:

Flag all the children.

document.flag_children_persisted

Returns:

  • (Array<Document>) —

    The flagged children.

Since:

  • 3.0.7



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# File 'lib/mongoid/traversable.rb', line 59

def flag_children_persisted
  _children.each do |child|
    child.new_record = false
  end
end

#hereditary? ⇒ true, false

Determines if the document is a subclass of another document.

Examples:

Check if the document is a subclass

Square.new.hereditary?

Returns:

  • (true, false) —

    True if hereditary, false if not.

Since:

  • 4.0.0



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# File 'lib/mongoid/traversable.rb', line 71

def hereditary?
  self.class.hereditary?
end

#parentize(document) ⇒ Document

Sets up a child/parent association. This is used for newly created objects so they can be properly added to the graph.

Examples:

Set the parent document.

document.parentize(parent)

Parameters:

  • document (Document) —

    The parent document.

Returns:

Since:

  • 4.0.0



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# File 'lib/mongoid/traversable.rb', line 84

def parentize(document)
  self._parent = document
end

#remove_child(child) ⇒ Object

Remove a child document from this parent. If an embeds one then set to nil, otherwise remove from the embeds many.

This is called from the RemoveEmbedded persistence command.

Examples:

Remove the child.

document.remove_child(child)

Parameters:

  • child (Document) —

    The child (embedded) document to remove.

Since:

  • 2.0.0.beta.1



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# File 'lib/mongoid/traversable.rb', line 99

def remove_child(child)
  name = child.metadata_name
  if child.embedded_one?
    remove_ivar(name)
  else
    relation = send(name)
    relation.send(:delete_one, child)
  end
end

#reset_persisted_children ⇒ Array<Document>

After children are persisted we can call this to move all their changes and flag them as persisted in one call.

Examples:

Reset the children.

document.reset_persisted_children

Returns:

Since:

  • 2.1.0



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# File 'lib/mongoid/traversable.rb', line 118

def reset_persisted_children
  _children.each do |child|
    child.move_changes
    child.new_record = false
  end
end