XML DOM

XML DOM Contents

The DOM Method: getAttribute()

The DOM Method: createNode()

The DOM Method: Create - other examples

The DOM Method: cloneNode()

The DOM Method: appendChild()

The DOM Method: abort()

The DOM Method: DOM object methods

The Node Type: NODE_TEXT

The Node Type: NODE_PROCESSING_INSTRUCTION

The Node Type: NODE_NOTATION

The Node Type: NODE_ENTITY_REFERENCE

The Node Type: NODE_ENTITY

The Node Type: NODE_ELEMENT

The Node Type: NODE_DOCUMENT_TYPE

The Node Type: NODE_DOCUMENT

The Node Type: NODE_COMMENT

The Node Type: NODE_CDATA_SECTION

The Node Type: NODE_ATTRIBUTE

The Node Type: 12 XML DOM Node types

<< XHTML			XmlSerializer >>

By :	Mark Wilson I am the creator of TopXML. I am available for international and local (Australia) contracts. I am a Solution Architect/Business Analyst. I have worked in IT in several countries (NZ, Australia, South Africa, UK) building and training teams for government and very large non-governmental organizations. I am ex-Microsoft Consulting Services. I wrote the first book on Microsoft XML published in 2000 called XML Programming with VB and ASP. Most recently I have been building tools for the SEO industry. Ask me for a 37 point SEO health-checkup for your website.
First posted :	03/24/2008
Times viewed :	2653

getElementsByTagName()

Is a member of:

DOMDocument
XMLDOMElement

Syntax

set objXMLDOMNodeList = objDOMDocument.getElementsByTagName(tagname)

Remark

The parameter Tagname in the getElementsByTagName() signature is a string, specifying the element name to find. If you specify that the tagname is an asterisk ("*"), then all the elements are returned in the DOMDocument.

The returned NodeList of this method is different from the nodeLists that we have dealt with so far. You normally work with a NodeList that returns a collection from the documentElement, such as:

set objXMLDOMNodeList = objDOMDocument.documentElement

This will return a NodeList collection that returns its child Nodes as shown in figure .

You can call getElementsByTagName() from the DOMDocument root, specifying that you want everything (*):

set objXMLDOMNodeList = objDOMDocument.getElementsByTagName("*")

In the above example, getElementsByTagName() returns a NodeList collection that has child Nodes as follows in figure :

This method returns a NodeList object in which each child Node is grouped by their element names, instead of being grouped by the normal TreeView effect.

Example

To get a clearer view of what we are trying to explain, look in your Local Views in VB for the following examples. See the difference in the collections of the NodeList object by calling:

Dim objDOMDocument As DOMDocument

Dim objNodeList As IXMLDOMNodeList

Set objDOMDocument = New DOMDocument

objDOMDocument.async = False

objDOMDocument.Load "http://localhost/xmlcode/people2.dtd"

Set objNodeList = objDOMDocument.documentElement

¬ Now look at the returned NodeList object in the Local Views in VB. Try the following:

Dim objDOMDocument As DOMDocument

Dim objNodeList As IXMLDOMNodeList

Set objDOMDocument = New DOMDocument

objDOMDocument.async = False

objDOMDocument.Load "http://localhost/xmlcode/people2.dtd"

Set objNodeList = objDOMDocument.getElementsByTagName("*")

¬ You can use this method when you want to get a specific Node, like NAME. However, take note that it returns a NodeList object; therefore, you need to iterate through the returned Nodes.

An example of this is when we want to put the NAME values of our element into a text box.

Set objNodeItems = objNode.getElementsByTagName("NAME")

txtName.Text = objNodeItems.Item(0).nodeTypedValue

¬ We indicate that we want the "NAME" element returned from the current Node.

¬ We want to get the value from the first Node in our collection.

For an easier method, look at the selectSingleNode() method later in this section.

This manuscript is an abridged version of a chapter from the Manning Publications book XML Programming with VB and ASP. This chapter looks at the Microsoft DOM objects. NOTE: Most images have been removed to increase speed and many of the code comments have also been removed for presentation. Please purchase the book to enjoy the full experience of all the chapters with images and code comments!