Calling insertBefore on Elements
If the current node is an element, calling insertBefore has the following results, depending on the value of the newChild parameter.
| Node type passed in newChild | Result |
|---|---|
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. |
Remarks
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.