GetNodeName is an abstract virtual method DOMString function. It is used to get the value for the NodeName property. It is overridden in descendent classes to provide the name needed for the DOM node specialization.

GetNodeValue is a DOMString function used to get the value for the NodeValue property. It is overridden in descendent classes to provide the value needed for the DOM node specialization. In TDOMNode, the method always returns an empty string ('').

SetNodeValue is a method used to set the NodeValue property to the value specified in AValue. It has an empty implementation in TDOMNode, and must be re-implemented in a descendent class to use the correct content for the DOM node specialization.

GetFirstChild always returns Nil for the property value. TDOMNode does not allocate storage for child nodes. The method must be re-implemented in a descendent class to which implements a DOM node specialization with child nodes.

The value for the property is retrieved from the revision number in the OwnerDocument for the node instance.

GetRevision is called from methods in TDOMNodeList which compare the revision numbers for a given node and the node list where it is stored. When the revision numbers differ, the node list is refreshed by calling the BuildList method in the TDOMNodeList instance.

Returns the value from the NodeValue property in TDOMNode.

Updates the value in NodeValue property in TDOMNode.

Changing is a procedure used to determine if the DOM node and its Owner document can be modified. Changing uses the Node Flags in the DOM node and its OwnerDocument to determine if the Node is marked as read-only and the document is not being freed.

Create is the constructor for the class instance. Creates stores the TDOMDocument instance in AOwner as the OwnerDocument for the DOM node. Create calls the inherited constructor.

Destroy is the destructor for the class instance. Destroy ensures that the ParentNode is notified that the node will be removed from the tree structure. When ParentNode is assigned, its DetachChild method is called to remove the class instance from the ChildNodes hierarchy.

Destroy calls the inherited destructor prior to exiting from the method.

FreeInstance is an overridden procedure used to perform actions needed when the class instance is freed. FreeInstance ensures that information in the internal TNodePool custom memory manager is updated, and the node is freed from its node pool. If the internal node pool has not been assigned, the inherited FreeInstance method is called.

Calls the GetChildNodeList method in OwnerDocument to get the list of child nodes for the current class instance. The property value is an empty node list if there are no child nodes in the current node.

Always returns 0 (zero) in TDOMNode. Overridden in descendent classes (like TDOMNode_WithChildren).

NodeName is a read-only DOMString property that contains the name for the DOM node. The read access specifier for the property is an abstract method in TDOMNode, and must be implemented in descendent classes to return the correct value for the DOM node specializations.

The values for NodeName, NodeValue, and Attributes vary according to the node type as follows:

NodeValue is a DOMString property that contains the value for the DOM node. Reading the value in NodeValue always results in an empty string ('') in TDOMNode, and writing the value for the property is not implemented. The access specifiers must be re-implemented in descendent classes to perform the actions required for the DOM node specializations.

The values for NodeName, NodeValue, and Attributes vary according to the node type as follows:

NodeType is a read-only Integer property that represents the DOM node type as defined in the DOM specification. The read access specifier in TDOMNode is an abstract method, and must be implemented in a descendent class to return the correct value for the DOM node specializations.

DOM node specializations use the following values in the NodeType property:

ParentNode is a read-only TDOMNode property that represents the DOM node that is the immediate ancestor of this node. All nodes, except TDOMAttr, TDOMDocument, TDOMDocumentFragment, TDOMEntity, and TDOMNotation may have a parent.

The value in ParentNode is assigned when TDOMNode methods like InsertBefore, InternalAppend, and AppendChild are called. The value in ParentNode is cleared when the DetachChild method is called, or when ChildNodes are freed.

Use ChildNodes to access the DOM nodes that are the immediate descendants of this node. Use PreviousSibling and NextSibling to access the respective DOM nodes that exist at the same Level in the DOM tree.

FirstChild is a read-only TDOMNode property that represents the first child node for this DOM node. In TDOMNode, the value for the property is always Nil (not assigned). The read access specifier is re-implemented in a descendent class (TDOMNode_WithChildren) to provide direct support for child node access.

LastChild is a read-only TDOMNode property that represents the last child node for this DOM node. In TDOMNode, the value for the property is always Nil (not assigned). The read access specifier is re-implemented in a descendent class (TDOMNode_WithChildren) to provide direct support for child node access.

ChildNodes is a read-only TDOMNodeList property used to provide access to the child nodes for the current DOM node. Reading the value in ChildNodes causes a TDOMNodeList to be created using the DOM tree in OwnerDocument. The list contains any DOM nodes found in OwnerDocument immediately below the current DOM node. If there are no child nodes for the current node, the list has a Length (or Count - they contain the same data) of 0 (zero). Use HasChildNodes to determine if the ChildNodes property contains any DOM nodes.

PreviousSibling is a read-only TDOMNode property that represents the previous DOM node at the same level in the DOM tree. If no previous node was found at the same level, the property is unassigned (contains Nil).

Use NextSibling to access the next node at the same level in the DOM tree.

NextSibling is a read-only TDOMNode property that represents the next DOM node at the same level in the DOM tree. If no successor node was found at the same level, the property is unassigned (contains Nil).

Use PreviousSibling to access the previous node at the same level in the DOM tree.

Attributes is a read-only TDOMNamedNodeMap property that contains attributes for the DOM node. Use the properties and methods in Attributes to access the DOM nodes by their name or ordinal position. Attributes also includes properties and methods that provide support for Namespace URIs and QualifiedNames as defined in the DOM specification.

While specified in TDOMNode, Attributes are valid only in the TDOMElement node type. For all other DOM node types the Attributes property is unassigned (contains Nil).

OwnerDocument is a read-only TDOMDocument property that represents the DOM document that created the node. OwnerDocument can be used to get access to the complete DOM tree for a document, or to access child nodes for any DOM node owned by the OwnerDocument.

In the TDOMDocument node specialization, the value in OwnerDocument is always unassigned (contains Nil).

GetEnumerator is a TDOMNodeEnumerator function used to get an enumerator for all top-level child nodes for the DOM node. It does not include any grandchildren (recursive access to child nodes).

GetEnumeratorAllChildren is a TDOMNodeAllChildEnumerator function used to get an enumerator for all nodes which are children or grandchildren for the node. Allows recursion into descendent nodes found in a child node.

GetNextNode is a TDOMNode function used to get the next child or sibling node in the DOM node hierarchy. GetNextNode visits nodes starting at the FirstChild node for the class instance. If FirstChild is not assigned, the GetNextNodeSkipChildren method is called to get the NextSibling node, or the NextSibling node in the ParentNode.

The return value is the TDOMNode which represents the next child or sibling node in the document hierarchy.

GetNextNode is called from the TDOMNodeAllChildEnumerator.MoveNext method.

GetNextNodeSkipChildren is a TDOMNode function used to get the next sibling node, ignoring all child nodes, for the current node.

The return value contains the TDOMNode that is the NextSibling for the current node, and can actually contain a previous sibling if NextSibling is unassigned. The return value is Nil when NextSibling is unassigned for both the current node and ParentNode.

GetNextNodeSkipChildren is used in the implementation of the TDOMNodeAllChildEnumerator.Create method, and called from the TDOMNode.GetNextNode method.

GetPreviousNode is a TDOMNode function used to get the previous node in the DOM node hierarchy.

The return value contains the last node (or leaf) in the node hierarchy for the PreviousSibling node as return from the GetLastLeaf method for the node. The return value is the ParentNode when PreviousSibling is unassigned.

GetPreviousNode is the converse of the GetNextNode method.

GetLastLeaf is a TDOMNode function used to the last node in the DOM node hierarchy for the current node.

The return value is Nil when LastChild has not been assigned for the current node. Otherwise, LastChild is called recursively until the given descendent node has no child nodes.

GetLastLeaf is used to implement the GetPreviousNode method.

GetLevel is a SizeInt function used to get the level for the current node in the DOM node hierarchy. The return value is determined by counting the number of ParentNode assignments starting with the current DOM node. A root-level node in a DOM document is at level 0 (zero).

InsertBefore is a TDOMNode function used to insert a new child node immediately before the referenced child node. In TDOMNode, InsertBefore always raises an EDOMHierarchyRequest exception. The method must be re-implemented in descendent classes which support child nodes in the DOM Node specialization.

ReplaceChild is a TDOMNode function which specifies the method used to replace a child node in the DOM sub-tree with the specified DOM node. NewChild is the DOM node to store in the DOM sub-tree. OldChild is the existing DOM node replaced with the new node value.

While TDOMNode specifies the method, it does not provide physical storage for child nodes. As a result, ReplaceChild always raises an EDOMHierarchyRequest exception and the return value is always Nil. ReplaceChild must be re-implemented in a descendent class to provide the functionality required for other DOM node specializations.

DetachChild is a TDOMNode function used to detach a specified child node from the DOM sub-tree for the current node. OldChild is the DOM node to remove from the DOM sub-tree. The return value contains the detached DOM node.

TDOMNode specifies the DetachChild method, but does not provide physical storage for child nodes. As a result, it always raises an EDOMNotFound exception in the method. DetachChild must be re-implemented in a descendent class as required for other DOM Node specializations.

RemoveChild is a TDOMNode function used to remove the node specified in OldChild from the ChildNodes sub-tree. RemoveChild calls the DetachChild method to detach the specified node from the OwnerDocument. The return value is the node in OldChild after it has been detached from the OwnerDocument and its internal node references have been updated.

AppendChild is a TDOMNode function used to append the node specified in NewChild as a child node in the hierarchy for the current class instance. AppendChild calls the InsertBefore method to make the specified node the first child node in the DOM hierarchy.

The return value contains the TDOMNode instance in NewChild after the node relationship in ParentNode, FirstChild, PreviousSibling, and NextSibling have been updated.

HasChildNodes is a Boolean function which indicates if the DOM node has child nodes. In general, the return value is True when a DOM node has been assigned to the FirstChild property.

HasChildNodes always returns False in TDOMNode. TDOMNode does not allocate storage for child nodes. The method must be overridden in a descendent class which allocates storage for child nodes in the DOM node specialization.

CloneNode is an overloaded TDOMNode function used to make a new copy of the current node. Deep indicates that child nodes are included in the new TDOMNode instance when set to True. An overloaded variant allows the DOM Document which owns the new node to be specified.

CloneNode always raises an EDOMNotSupported exception in TDOMNode, and the return value is always Nil. It must be overridden in a descendent class to perform any actions needed for the DOM node specialization.

IsSupported is a Boolean function which indicates whether the DOM implementation implements a specific feature and that feature is supported in this node. IsSupported implements the DOM Node method defined in the DOM Level 2 Specification.

Feature contains the name for the feature or module to check in the method.

Version contains the conformance level for the specified Feature. Both values are used as arguments to the TDOMImplementation.HasFeature method.

Returns True if the specified feature at the given conformance level is supported for the node, or False when not implemented.

HasAttributes is a Boolean function which indicates if the DOM node attribute names and/or values. HasAttributes implements the method defined for the DOM Node interface in the DOM Level 2 Specification.

The return value is True when a TDOMNamedNodeMap has been assigned for the node, and it has a non-zero value in its Length (or Count) property.

Normalize is a method used to convert child text nodes in the sub-tree to their normal form where only structure nodes separate the text nodes. Adjacent text nodes are combined into a single text node. Adjacent text nodes which contain only ignorable whitespace are consolidated into a single whitespace value.

Normalize implements the method defined for the DOM Node interface in the DOM Level 2 Specification.

NamespaceURI is a read-only DOMString property with the Namespace URI (Universal Resource Identifier) for the DOM node, or an empty string when it has not been specified. NamespaceURI is determined using a namespace lookup for the value declared when the node is created.

For nodes other than node type ELEMENT_NODE (TDOMElement) and ATTRIBUTE_NODE (TDOMAttr), and nodes created with a DOM Level 1 method, such as createElement from the Document interface, this is always an empty DOMString.

The property value is always an empty string ('') in TDOMNode. In a descendent class (like TDOMNode_NS), it will contain one of the Namespace URLs registered in the OwnerDocument for the node.

NamespaceURI implements the attribute from the Node interface in the DOM Level 2 Specification.

LocalName is a read-only DOMString property with the local part of the qualified name for the node. A qualified name consists of a delimited namespace Prefix and the name for the element or attribute in the node. Local name contains only the element or attribute name, without the Prefix for the namespace.

For the following Qualified Names:

• XML:ID
• XLink:href

The Prefix values are:

• XML
• XLink

The LocalName values are:

• ID
• href

For nodes other than ELEMENT_NODE (TDOMELement) and ATTRIBUTE_NODE (TDOMAttr), and nodes created with a DOM Level 1 method, such as createElement from the Document interface, the property value is is always an empty DOMString.

The property value is always an empty DOMString value in TDOMNode. In a descendent class (like TDOMNode_NS), it will contain the actual NodeName for an element or attribute.

Prefix is a DOMString property which contains the prefix part of a qualified name used for the node. Prefix is the identifier used for the namespace URI, and is included in the value for the NodeName property which includes the qualified name. When a qualified name is not used in NodeName, Prefix contains an empty DOMString value (''). Use LocalName for the value in NodeName without the value in Prefix.

Prefix applies to the DOM Element and Attribute node types. For nodes of any type other than ELEMENT_NODE (TDOMElement) and ATTRIBUTE_NODE (TDOMAttr) and nodes created with a DOM Level 1 method, such as createElement from the Document interface, this is always an empty DOMString value.

Prefix implements the Prefix attribute for the DOM Node interface in the DOM Level 2 Specification.

TextContent is a DOMString property the textual content for a DOM node (and its specialized descendants), as specified in the DOM Level 3 specification.

In TDOMNode, the value in TextContent is redirected to the NodeValue property. The read and write access specifiers may be overridden in descendent classes to perform actions needed for a particular DOM Node specialization, including:

• TDOMProcessingInstruction
• TDOMCharacterData
• TDOMText
• TDOMAttr

LookupPrefix is a DOMString function used to locate the Prefix associated with the NameSpace URI specified in the nsURI argument. LookupPrefix implements the DOM Node interface specified in the DOM Level 3 specification.

In TDOMNode, the return value is always an empty DOMString (''). Descendent classes which implement a specific DOM Node specialization (like TDOMElement) will provide an InternalLookupPrefix method used to get the return value. The internal GetAncestorElement routine is used to find Prefix / Namespace associations in ancestor nodes.

LookupNamespaceURI is a DOMString function used to get the NamespaceURI associated with the Prefix specified in the APrefix argument. LookupNamespaceURI implements the method for the DOM Node interface as specified in the DOM Level 3 specification.

LookupNamespaceURI ensures that the DOM node uses the ELEMENT_NODE node type required for namespace support. If the node is not a DOM Element (TDOMElement), the ancestor nodes are checked for a TDOMDocument or TDOMAttrib node which can supply the namespace information.

LookupNamespaceURI compares the value in the Prefix property to the argument in APrefix. When a match is found, the NamespaceURI for the node is used as the return value. When a namespace is not found for the prefix, the return value is an empty DOMString ('').

IsDefaultNamespace is a Boolean function which indicates if the Namespace URI in the nsURI argument is the default value for the DOM node.

BaseURI is a read-only DOMString property with the Base Universal Resource Identifier (URI) for the node relative to its context.

BaseURI is specified in the DOM Level 3 Specification. It is not defined in the DOM Level 2 APIs. The implementation in TDOMNode is incomplete as per the DOM Level 3 specification.

In the DOM specification, BaseURI is a dynamically computed value starting with the xml:base attribute for a given document. It includes the DocumentURI for the owner document, and should also include the node path to the current node.

In TDOMNode, BaseURI is resolved to the DocumentURI in the OwnerDocument when the node type is a document node or a processing instruction. It does not include the xml:base attribute that may (or may not ) be present in the owner document.

For all other node types, the property value is an empty string ('').

FindNode is a TDOMNode function used to locate a child node in the class instance with the value in ANodeName in its NodeName property. The return value contains the TDOMNode instance with the specified name, or Nil if a node is not found with the specified name.

FindNode always returns Nil in TDOMNode since physical storage is not allocated in TDOMNode for child node instances. It must be overridden in a descendent class to performs actions needed for the DOM node specialization.

CompareName is an Integer function used to compare the value in NodeName to the value specified in the name argument. NodeName and name are converted to DOMPChar types and passed as arguments an implementation routine used to compare the values.

The return value contains the difference between the ordinal character values for the first non-matching characters in the compared names. When the return value is 0 (zero), the compared values have the same content.

Flags is a TNodeFlags property which contains zero or more values from the TNodeFlagEnum enumeration that indicate the conformance level or state for the node. See TNodeFlagEnum for more information about the values in the enumeration and their meanings.

Values in Flags are used and updated in various methods like Normalize and GetTextContent. It is also updated when the SetReadOnly method is called.

TDOMNode_WithChildren is a TDOMNode descendant which allocates storage for child nodes in the class instance. TDOMNode_WithChildren is an extension to the Node interface in the DOM specification, and is designed to save memory in a large DOM tree.