insertBefore Method
Inserts a child node to the left of the specified node, or at the end of the list.
Script Syntax
var objXMLDOMNode = oXMLDOMNode.insertBefore(newChild, refChild);
Parameters
- newChild
- An object. The address of the new node to be inserted.
- refChild
- A variant. The address of the reference node; the
newChild
parameter is inserted to the left of therefChild
parameter. If Null, thenewChild
parameter is inserted at the end of the child list.
Return Value
Object. On success, returns the child node that was inserted.
Example
The following script example creates a new IXMLDOMNode
object and inserts it before the second child of the top-level node.
var xmlDoc = new ActiveXObject("Msxml2.DOMDocument.5.0"); var root; var newNode; var currNode; xmlDoc.async = false; xmlDoc.load("books.xml"); if (xmlDoc.parseError.errorCode != 0) { var myErr = xmlDoc.parseError; alert("You have error " + myErr.reason); } else { root = xmlDoc.documentElement; alert(root.xml); newNode = xmlDoc.createNode(1, "VIDEOS", ""); currNode = root.insertBefore(newNode, root.childNodes.item(1)); alert(root.xml); }
Visual Basic Syntax
Set objXMLDOMNode = oXMLDOMNode.insertBefore(newChild, refChild)
Parameters
- newChild
- An object. The address of the new node to be inserted.
- refChild
- A variant. The address of the reference node; the
newChild
parameter is inserted to the left of therefChild
parameter. If Null, thenewChild
parameter is inserted at the end of the child list.
Return Value
An object. On success, returns the child node that was inserted.
Example
The following Visual Basic example creates a new IXMLDOMNode
object and inserts it before the second child of the top-level node.
Dim xmlDoc As New Msxml2.DOMDocument50 Dim root As IXMLDOMElement Dim newNode As IXMLDOMNode Dim currNode As IXMLDOMNode xmlDoc.async = False xmlDoc.Load ("books.xml") If (xmlDoc.parseError.errorCode <> 0) Then Dim myErr Set myErr = xmlDoc.parseError MsgBox("You have error " & myErr.reason) Else Set root = xmlDoc.documentElement MsgBox root.xml Set newNode = xmlDoc.createNode(NODE_ELEMENT, "VIDEOS", "") Set currNode = root.insertBefore(newNode, root.childNodes.Item(1)) MsgBox root.xml End If
C/C++ Syntax
HRESULT insertBefore( IXMLDOMNode *newChild, VARIANT refChild, IXMLDOMNode **outNewChild);
Parameters
- newChild [in]
- The address of the new node to be inserted. The node passed here must be a valid child of the current XML DOM document node. For example, if the current node is an attribute, you cannot pass another attribute in the
newChild
parameter, because an attribute cannot have an attribute as a child.If
newChild
is of DOCUMENT_FRAGMENT node type, all its children are inserted in order beforerefChild
. IfnewChild
is already in the tree, it is first removed before it is reinserted before therefChild
node. Read-only nodes, such as NODE_DOCUMENT_TYPE and NODE_ENTITY nodes, cannot be passed in thenewChild
parameter. - refChild [in]
- The address of the reference node. The node specified is where the
newChild
node is to be inserted to the left as the preceding sibling in the child list. The node passed here must be a either a child node of the current node or Null. If the value is Null, thenewChild
node is inserted at the end of the child list. If therefChild
node is not a child of the current node, an error is returned. - outNewChild [out, retval]
- On success, the child node that was inserted. If Null, no object is created.
C/C++ Return Values
- S_OK
- The value returned if successful.
- E_INVALIDARG
- The value returned if the
newChild
parameter is Null. - E_FAIL
- The value returned if an error occurs.
Remarks
The following are general remarks about the insertBefore
method when DTD/schema rules or namespace prefixes are involved.
How DTD/Schema definitions are resolved
The newChild
and refChild
parameters can represent nodes in the same document or in different documents. When in the same document, the nodes retain their default attributes and data types. When in different documents, the nodes either lose or alter their default attributes, depending on whether the document that contains them has a document type definition (DTD) or other schema. MSXML attempts to correctly merge the different DTDs.
If the newChild
node's DTD or schema differs from that of 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 in which elements are defined based upon how they are used in the current DOM document instance but any attributes within the newChild
node fragment lose their data types and defaults. Cutting and pasting between documents with two different DTDs can result in an invalid document that might fail to parse after being saved.
How conflicts between prefixes and namespaces are resolved
If there is a conflict between prefixes on the containing element and the 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 namespace, as in the following.
xmlns:myns="URN1"
The error can 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"
Namespace conflict errors 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 with the containing element, insertBefore
returns an error.
Further remarks
The use and operation of the insertBefore
method depends on the value of the nodeType
property for the IXMLDOMNode
type object passed in the newChild
parameter. The following topics provide further information about the results of calling insertBefore
on different types of nodes.
- Calling insertBefore on Attributes
- Calling insertBefore on Documents
- Calling insertBefore on Document Fragments
- Calling insertBefore on Elements
To view reference information for Visual Basic, C/C++, or Script only, click the Language Filter button in the upper-left corner of the page.
See Also
createNode Method | nodeType Property
Applies to: IXMLDOMAttribute | IXMLDOMCDATASection | IXMLDOMCharacterData | IXMLDOMComment | DOMDocument | IXMLDOMDocumentFragment | IXMLDOMDocumentType | IXMLDOMElement | IXMLDOMEntity | IXMLDOMEntityReference | IXMLDOMNode | IXMLDOMNotation | IXMLDOMProcessingInstruction | IXMLDOMText