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

#_childrenArray<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

Since:

  • 4.0.0


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# File 'lib/mongoid/traversable.rb', line 29

def _children
  @__children ||= collect_children
end

#_parentObject

Since:

  • 4.0.0


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# File 'lib/mongoid/traversable.rb', line 10

def _parent
  @__parent
end

#_parent=(p) ⇒ Object

Since:

  • 4.0.0


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# File 'lib/mongoid/traversable.rb', line 14

def _parent=(p)
  @__parent = p
end

#_reset_memoized_children!nil

Resets the memoized children on the object. Called internally when an embedded array changes size.

Examples:

Reset the memoized children.

document._reset_memoized_children!

Since:

  • 5.0.0


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# File 'lib/mongoid/traversable.rb', line 141

def _reset_memoized_children!
  @__children = nil
end

#_rootDocument

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

Since:

  • 4.0.0


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# File 'lib/mongoid/traversable.rb', line 152

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?

Since:

  • 3.1.0


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# File 'lib/mongoid/traversable.rb', line 166

def _root?
  _parent ? false : true
end

#collect_childrenArray<Document>

Collect all the children of this document.

Examples:

Collect all the children.

document.collect_children

Since:

  • 2.4.0


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# File 'lib/mongoid/traversable.rb', line 41

def collect_children
  children = []
  embedded_relations.each_pair do |name, |
    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_persistedArray<Document>

Marks all children as being persisted.

Examples:

Flag all the children.

document.flag_children_persisted

Since:

  • 3.0.7


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# File 'lib/mongoid/traversable.rb', line 63

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?

Since:

  • 4.0.0


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# File 'lib/mongoid/traversable.rb', line 75

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)

Since:

  • 4.0.0


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# File 'lib/mongoid/traversable.rb', line 88

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)

Since:

  • 2.0.0.beta.1


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# File 'lib/mongoid/traversable.rb', line 103

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

#reset_persisted_childrenArray<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

Since:

  • 2.1.0


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# File 'lib/mongoid/traversable.rb', line 122

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