OuterXml

OuterXml is a property found in many XML DOM implementations, most notably in the .NET Framework’s System.Xml.XmlNode class. It returns a string containing the XML markup that represents the node and all of its descendant nodes. This is in contrast to InnerXml, which returns only the markup for the node’s children and not the node itself. OuterXml is a read-only property, meaning it cannot be assigned to directly; to replace a node’s markup you typically create a new node or fragment from a string and modify the tree with DOM methods such as ReplaceChild or by loading the string into a document.

In practice, OuterXml yields different results depending on the node type. For an element node, OuterXml includes the element’s start tag, its content, and the end tag (for example, <book><title>XML</title></book>). For a text node, OuterXml returns the text content itself. For a comment node, it returns the comment markup (<!-- comment -->). For a document node, OuterXml represents the complete document markup, including the declaration if present.

Common uses of OuterXml include obtaining a complete serialized representation of a node subtree for logging, debugging, or transmission, and cloning a subtree by parsing the OuterXml string back into a new node. Because OuterXml serializes the entire subtree, its use can be relatively expensive for large XML structures, so it is typically employed when a full, self-contained representation is required.

In summary, OuterXml provides the complete XML markup for a node and its descendants as a string, serving as a convenient way to serialize or clone particular portions of an XML DOM.