XML Classes Summary

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XML Classes Summary

The following pages provide detailed information on the classes used to create, parse, and modify XML (eXtensible Markup Language) documents. These classes handle XML text documents by converting them to and from a tree structure that is stored in the controller’s memory. A parsed XML document tree consists of nodes for items in the document, arranged in a tree that reflects how items in the text document are nested. The tree is constructed using a subset of the Document Object Model (DOM) Core Interfaces as described in: http://www.w3.org/TR/REC-DOM-Level-1 and methods similar to those found in Visual Basic.NET.

There are two built-in classes in GPL to handle XML document objects.

XmlDocClass objects operate on the top-level of a DOM tree, which contains an entire XML document. The nodes within the tree contain the data from the document. The XmlDoc methods deal with the document as a whole, for example loading it into memory or saving it to a file. There is one and only one XmlDoc object for each separate XML document, although there can be multiple pointers to this object. An XML DOM tree cannot exist without an XmlDoc object.

XmlNodeClass objects point to individual nodes in a DOM document tree. Its methods support accessing or modifying node data or properties, and adding or removing nodes in the tree structure. These objects point to DOM nodes but do not actually contain the DOM nodes. When an XmlNode object is created or destroyed, the underlying DOM nodes are not affected provided that they are part of a DOM tree. See Table 19-115.

Table 19-115: XML Classes Summary
XmlDoc Class Member	Type	Description
New	Constructor Method	Creates a new document tree with the specified name.
xmldoc_obj.CreateNode	Method	Returns a new XmlNode object for this document with the specified type, and name.
XmlDoc.DecodeEntities	Shared Method	Converts a String containing encoded XML entities into raw text.
xmldoc_obj. DocumentElement	Method	Returns the XmlNode element that is the root of the document.
XmlDoc.EncodeEntities	Shared Method	Converts special characters in a String to XML entities.
xmldoc_obj.ErrorCode	Get Property	Returns the last parser error code number, or 0 if no error.
XmlDoc.LoadFile	Shared Method	Loads and parses an XML text document from a file and returns the created XmlDoc DOM tree object.
XmlDoc.LoadString	Shared Method	Parses an XML text document from a String and returns the created XmlDoc DOM tree object.
xmldoc_obj.Message	Get Property	Returns the last parser error message, or “” if no error.
xmldoc_obj.SaveFile	Method	Converts a DOM tree document to the XML text format and writes the data to a file.
xmldoc_obj.SaveString	Method	Converts a DOM tree document to the XML text format and writes the data to a String.

The XmlNode class interface is summarized in Table 19-116:

Table 19-116: XmlNode Class Interface
XmlNode Class Member	Type	Description
xmlnode_obj.AddAttribute	Method	Adds an attribute node as a child of this node.
xmlnode_obj.AddElement	Method	Adds an element node as a child of this node. Includes an optional value.
xmlnode_obj.AddElementNode	Method	Adds an element node as a child of this node. Returns an XmlNode object for the new node. Includes an optional value.
xmlnode_obj.AppendChild	Method	Appends a new child node as the last child of this node. Merges text nodes.
xmlnode_obj.ChildNodeCount	Get Property	Returns the number of children of this node.
xmlnode_obj.Clone	Method	Returns a clone of this node. Optionally recursively clones the subtree under this node.
xmlnode_obj.FirstChild	Method	Returns the first child of this node.
xmlnode_obj.GetAttribute	Method	Returns a String containing the value of the specified attribute that is a child of this node.
xmlnode_obj.GetAttributeNode	Method	Returns the node corresponding to the specified attribute that is a child of this node.
xmlnode_obj.GetElement	Method	Returns a String containing the value of the specified element that is a child of this node.
xmlnode_obj.GetElementNode	Method	Returns the node corresponding to the specified element that is a child of this node.
xmlnode_obj.HasAttribute	Method	Returns True if the specified attribute is a child of this node.
xmlnode_obj.HasChildNodes	Get Property	Returns True if the node has any non-attribute child nodes.
xmlnode_obj.HasElement	Method	Returns True if a specified element is a child of this node.
xmlnode_obj.InsertAfter	Method	Inserts a new node as a child of this node after a referenced child node. Merges text nodes.
xmlnode_obj.InsertBefore	Method	Inserts a new node as a child of this node before a referenced child node. Merges text nodes.
xmlnode_objLastChild	Method	Returns the last child of this node.
xmlnode_obj.Name	Get Property	Returns the node name as a String.
xmlnode_obj.NextSibling	Method	Returns the next sibling of this node.
xmlnode_obj.OwnerDocument	Method	Returns the XmlDoc associated with this node.
xmlnode_obj.ParentNode	Method	Returns the parent of this node.
xmlnode_obj.PreviousSibling	Method	Returns the previous sibling of this node.
xmlnode_obj.RemoveAttribute	Method	Removes a specified attribute from this node's children.
xmlnode_obj.RemoveChild	Method	Removes a child node from the list of children for this node.
xmlnode_obj.RemoveElement	Method	Removes a specified element from this node's children.
xmlnode_obj.ReplaceChild	Method	Replaces an old child node with a new child node.
xmlnode_obj.SetAttribute	Method	Sets the value of an existing specified attribute that is a child of this node.
xmlnode_obj.SetElement	Method	Sets the value of an existing specified element that is a child of this node.
xmlnode_obj.Type	Get Property	Returns the node type as a String.
xmlnode_obj.Value	Get/Set Property	Returns the node value as a String or sets the node value.