IXMLDOMNode::insertBefore Method

---

Inserts a child node to the left of the specified node or at the end of the list.

Visual Basic Syntax

Set objXMLDOMNode = oXMLDOMNode.insertBefore(newChild, refChild)

C/C++ Syntax

HRESULT insertBefore(
    IXMLDOMNode *newChild,
    VARIANT refChild,
    IXMLDOMNode **outNewChild);

Parameters

newChild

[in] Address of the new node to be inserted.

refChild

[in] Address of the reference node; newChild is inserted to the left of refChild. If NULL, newChild is inserted at the end of the child list.

outNewChild

[out] On success, the child node that was inserted. If NULL, no object is created.

C/C++ Return Values

S_OK

Value returned if successful.

E_INVALIDARG

Value returned if newChild is null.

E_FAIL

Value returned if an error occurs.

Remarks

When moving a node, it retains its namespace information. Moving a node doesn't create a namespace declaration, but declarations are added when retrieving the XML source (via the IXMLDOMDocument::save or IXMLDOMNode::get_xml methods) to ensure that all namespaces are properly declared.

When inserting a node tree under another node that has a different owner document, the ownerDocument property for each inserted node is changed to match the owner document of its new parent.

When moving a node tree to another document, the content of all entity reference nodes contained therein is updated to conform with the new document. So if the new document does not declare an entity that was moved into it, the entity reference will have no children, and the old content is removed. Existing references to nodes under the entity reference are still valid, but the node whose parent perviously was the entity reference now has a null parent.

This operation depends on the value of the nodeType property.

NODE_ATTRIBUTE

This operation depends on the value of the newChild parameter.

NODE_ATTRIBUTE, NODE_CDATA_SECTION, NODE_COMMENT, NODE_DOCUMENT, NODE_DOCUMENT_TYPE, NODE_ELEMENT, NODE_ENTITY, NODE_NOTATION, NODE_PROCESSING_INSTRUCTION	Returns an error. These node types cannot be children of an attribute.
NODE_DOCUMENT_FRAGMENT	Inserts the children of the document fragment (newChild) and returns newChild.
NODE_ENTITY_REFERENCE, NODE_TEXT	Inserts newChild and returns newChild.
NODE_CDATA_SECTION, NODE_COMMENT, NODE_ENTITY, NODE_NOTATION, NODE_PROCESSING_INSTRUCTION, NODE_TEXT	Returns an error. These node types either cannot have children or their children are read-only.

NODE_DOCUMENT

This operation depends on the value of the newChild parameter.

NODE_ATTRIBUTE, NODE_CDATA_SECTION, NODE_DOCUMENT, NODE_ENTITY, NODE_ENTITY_REFERENCE, NODE_NOTATION, NODE_TEXT	Returns an error. These nodes are not valid as children of a document node.
NODE_COMMENT, NODE_PROCESSING_INSTRUCTION	Inserts newChild and returns newChild.
NODE_DOCUMENT_TYPE, NODE_ELEMENT	Inserts newChild and returns newChild. Note, however, that by definition an XML document (the Document node) can have only a single child. Therefore, an error is returned if the document node already has a child.
NODE_DOCUMENT_FRAGMENT	Inserts the children of the document fragment (in newChild) and returns newChild. Note that the insert operations are subject to the rules for child nodes and can fail if the document fragment children represent node types that cannot be inserted.
NODE_DOCUMENT_TYPE	Returns an error. The document type is read-only.

NODE_DOCUMENT_FRAGMENT

This operation depends on the value of the newChild parameter.

NODE_ATTRIBUTE, NODE_DOCUMENT, NODE_DOCUMENT_TYPE	Returns an error. These nodes types are not valid as children of a document fragment.
NODE_CDATA_SECTION, NODE_COMMENT, NODE_ELEMENT, NODE_ENTITY_REFERENCE, NODE_PROCESSING_INSTRUCTION, NODE_TEXT	Inserts newChild and returns newChild.
NODE_DOCUMENT_FRAGMENT	Inserts the children of the document fragment (newChild) and returns newChild.
NODE_ENTITY, NODE_NOTATION	Returns an error. Entities and notations are read-only and cannot be inserted into a document.

NODE_ELEMENT

This operation depends on the value of the newChild parameter.

NODE_CDATA_SECTION, NODE_COMMENT, NODE_ELEMENT, NODE_ENTITY_REFERENCE, NODE_TEXT, NODE_PROCESSING_INSTRUCTION	Inserts newChild and returns newChild.
NODE_ATTRIBUTE, NODE_DOCUMENT, NODE_DOCUMENT_TYPE, NODE_ENTITY, NODE_NOTATION	Returns an error. These node types cannot be children of an element node.
NODE_DOCUMENT_FRAGMENT	Inserts the children of the document fragment (newChild) and returns newChild.
NODE_ENTITY_REFERENCE	Returns an error. Although the child nodes of an entity reference are the expanded entity, the children cannot be modified.

The node supplied in refChild must be a child node of this node or null. The newChild is inserted before refChild (as the left sibling) in the child list. If refChild is null, newChild is inserted at the end of the child list. If refChild is not a child of this node, an error is returned.

If newChild is a node of type DOCUMENT_FRAGMENT, all its children are inserted, in the same order, before refChild. If newChild is already in the tree, it is first removed.

The parameters can represent nodes in the same document or in different documents. When within the same document, the nodes retain their default attributes and data types. When the parameters represent nodes in different documents, the nodes either lose or alter their default attributes depending on whether this node's document has a document type definition (DTD) or other schema. The Microsoft implementation attempts to correctly merge the different DTDs.

If the newChild node's DTD or schema differs from the original document, the nodes will be treated with the definitions in the new DTD, including default attributes and data types. If there is no DTD, the nodes keep their data types by picking up an instance definition (attributes lose their data type), and default attributes are lost. Note also that cutting and pasting between documents with two different DTDs can result in an invalid document that can fail to parse after being saved.

When elements are added as children to other elements, they introduce their own namespace scoping. That is, if the element is from a default namespace, the default has scope beginning with the element being added.

If an entity reference is being added as a child to an element or document fragment, the namespace declaration of the entity reference is added to the containing element. Similarly, if the entity reference is being added to an attribute, the namespace and the prefix of the entity reference are added to the element containing the attribute.

When adding a document fragment, the containing element adds all namespaces and prefixes from the document fragment. If this causes a conflict on the containing element, insertBefore returns an error.

If there is a conflict between prefixes on the containing element and the attribute prefixes being added, the insertBefore operation fails and returns an error. For example, a conflict occurs when a new attribute referring to a different namespace is added to an element with the following namespace:

xmlns:myns="URN1"

The error could result from the new attribute, where "myns" refers to a different namespace, "URN2", such as would result from a call to createNode ("attribute","myns:myname","URN2").

myns:myname="myattributevalue"

Note that namespace conflict errors can occur only when setting attributes. Inserted child elements do not cause a namespace conflict.

When adding a document fragment, the containing element adds all namespaces and prefixes from the document fragment. If this causes a conflict on the containing element, insertBefore returns an error.