documentfragment(3)
NAME
XML::DOM::DocumentFragment - Facilitates cut & paste in
XML::DOM documents
DESCRIPTION
XML::DOM::DocumentFragment extends XML::DOM::Node
DocumentFragment is a "lightweight" or "minimal" Document
object. It is very common to want to be able to extract a
portion of a document's tree or to create a new fragment
of a document. Imagine implementing a user command like
cut or rearranging a document by moving fragments around.
It is desirable to have an object which can hold such
fragments and it is quite natural to use a Node for this
purpose. While it is true that a Document object could
fulfil this role, a Document object can potentially be a
heavyweight object, depending on the underlying implemen
tation. What is really needed for this is a very
lightweight object. DocumentFragment is such an object.
Furthermore, various operations -- such as inserting nodes
as children of another Node -- may take DocumentFragment
objects as arguments; this results in all the child nodes
of the DocumentFragment being moved to the child list of
this node.
The children of a DocumentFragment node are zero or more
nodes representing the tops of any sub-trees defining the
structure of the document. DocumentFragment nodes do not
need to be well-formed XML documents (although they do
need to follow the rules imposed upon well-formed XML
parsed entities, which can have multiple top nodes). For
example, a DocumentFragment might have only one child and
that child node could be a Text node. Such a structure
model represents neither an HTML document nor a wellformed XML document.
- When a DocumentFragment is inserted into a Document (or
indeed any other Node that may take children) the children
of the DocumentFragment and not the DocumentFragment
itself are inserted into the Node. This makes the Docu
mentFragment very useful when the user wishes to create
nodes that are siblings; the DocumentFragment acts as the
parent of these nodes so that the user can use the stan
dard methods from the Node interface, such as insertBe_ fore() and appendChild().