- Sams Teach Yourself XML in 21 Days, Third Edition
- Table of Contents
- About the Author
- Acknowledgments
- We Want to Hear from You!
- Introduction
- Part I: At a Glance
- Day 1. Welcome to XML
- All About Markup Languages
- All About XML
- Looking at XML in a Browser
- Working with XML Data Yourself
- Structuring Your Data
- Creating Well-Formed XML Documents
- Creating Valid XML Documents
- How XML Is Used in the Real World
- Online XML Resources
- Summary
- Q&A
- Workshop
- Day 2. Creating XML Documents
- Choosing an XML Editor
- Using XML Browsers
- Using XML Validators
- Creating XML Documents Piece by Piece
- Creating Prologs
- Creating an XML Declaration
- Creating XML Comments
- Creating Processing Instructions
- Creating Tags and Elements
- Creating CDATA Sections
- Handling Entities
- Summary
- Q&A
- Workshop
- Day 3. Creating Well-Formed XML Documents
- What Makes an XML Document Well-Formed?
- Creating an Example XML Document
- Understanding the Well-Formedness Constraints
- Using XML Namespaces
- Understanding XML Infosets
- Understanding Canonical XML
- Summary
- Q&A
- Workshop
- Day 4. Creating Valid XML Documents: DTDs
- All About DTDs
- Validating a Document by Using a DTD
- Creating Element Content Models
- Commenting a DTD
- Supporting External DTDs
- Handling Namespaces in DTDs
- Summary
- Q&A
- Workshop
- Declaring Attributes in DTDs
- Day 5. Handling Attributes and Entities in DTDs
- Specifying Default Values
- Specifying Attribute Types
- Handling Entities
- Summary
- Q&A
- Workshop
- Day 6. Creating Valid XML Documents: XML Schemas
- Using XML Schema Tools
- Creating XML Schemas
- Dissecting an XML Schema
- The Built-in XML Schema Elements
- Creating Elements and Types
- Specifying a Number of Elements
- Specifying Element Default Values
- Creating Attributes
- Summary
- Q&A
- Workshop
- Day 7. Creating Types in XML Schemas
- Restricting Simple Types by Using XML Schema Facets
- Creating XML Schema Choices
- Using Anonymous Type Definitions
- Declaring Empty Elements
- Declaring Mixed-Content Elements
- Grouping Elements Together
- Grouping Attributes Together
- Declaring all Groups
- Handling Namespaces in Schemas
- Annotating an XML Schema
- Summary
- Q&A
- Workshop
- Part I. In Review
- Well-Formed Documents
- Valid Documents
- Part II: At a Glance
- Day 8. Formatting XML by Using Cascading Style Sheets
- Our Sample XML Document
- Introducing CSS
- Connecting CSS Style Sheets and XML Documents
- Creating Style Sheet Selectors
- Using Inline Styles
- Creating Style Rule Specifications in Style Sheets
- Summary
- Q&A
- Workshop
- Day 9. Formatting XML by Using XSLT
- Introducing XSLT
- Transforming XML by Using XSLT
- Writing XSLT Style Sheets
- Using <xsl:apply-templates>
- Using <xsl:value-of> and <xsl:for-each>
- Matching Nodes by Using the match Attribute
- Working with the select Attribute and XPath
- Using <xsl:copy>
- Using <xsl:if>
- Using <xsl:choose>
- Specifying the Output Document Type
- Summary
- Q&A
- Workshop
- Day 10. Working with XSL Formatting Objects
- Introducing XSL-FO
- Using XSL-FO
- Using XSL Formatting Objects and Properties
- Building an XSL-FO Document
- Handling Inline Formatting
- Formatting Lists
- Formatting Tables
- Summary
- Q&A
- Workshop
- Part II. In Review
- Using CSS
- Using XSLT
- Using XSL-FO
- Part III: At a Glance
- Day 11. Extending HTML with XHTML
- Why XHTML?
- Writing XHTML Documents
- Validating XHTML Documents
- The Basic XHTML Elements
- Organizing Text
- Formatting Text
- Selecting Fonts: <font>
- Comments: <!-->
- Summary
- Q&A
- Workshop
- Day 12. Putting XHTML to Work
- Creating Hyperlinks: <a>
- Linking to Other Documents: <link>
- Handling Images: <img>
- Creating Frame Documents: <frameset>
- Creating Frames: <frame>
- Creating Embedded Style Sheets: <style>
- Formatting Tables: <table>
- Creating Table Rows: <tr>
- Formatting Table Headers: <th>
- Formatting Table Data: <td>
- Extending XHTML
- Summary
- Q&A
- Workshop
- Day 13. Creating Graphics and Multimedia: SVG and SMIL
- Introducing SVG
- Creating an SVG Document
- Creating Rectangles
- Adobe's SVG Viewer
- Using CSS Styles
- Creating Circles
- Creating Ellipses
- Creating Lines
- Creating Polylines
- Creating Polygons
- Creating Text
- Creating Gradients
- Creating Paths
- Creating Text Paths
- Creating Groups and Transformations
- Creating Animation
- Creating Links
- Creating Scripts
- Embedding SVG in HTML
- Introducing SMIL
- Summary
- Q&A
- Workshop
- Day 14. Handling XLinks, XPointers, and XForms
- Introducing XLinks
- Beyond Simple XLinks
- Introducing XPointers
- Introducing XBase
- Introducing XForms
- Summary
- Workshop
- Part III. In Review
- Part IV: At a Glance
- Day 15. Using JavaScript and XML
- Introducing the W3C DOM
- Introducing the DOM Objects
- Working with the XML DOM in JavaScript
- Searching for Elements by Name
- Reading Attribute Values
- Getting All XML Data from a Document
- Validating XML Documents by Using DTDs
- Summary
- Q&A
- Workshop
- Day 16. Using Java and .NET: DOM
- Using Java to Read XML Data
- Finding Elements by Name
- Creating an XML Browser by Using Java
- Navigating Through XML Documents
- Writing XML by Using Java
- Summary
- Q&A
- Workshop
- Day 17. Using Java and .NET: SAX
- An Overview of SAX
- Using SAX
- Using SAX to Find Elements by Name
- Creating an XML Browser by Using Java and SAX
- Navigating Through XML Documents by Using SAX
- Writing XML by Using Java and SAX
- Summary
- Q&A
- Workshop
- Day 18. Working with SOAP and RDF
- Introducing SOAP
- A SOAP Example in .NET
- A SOAP Example in Java
- Introducing RDF
- Summary
- Q&A
- Workshop
- Part IV. In Review
- Part V: At a Glance
- Day 19. Handling XML Data Binding
- Introducing DSOs
- Binding HTML Elements to HTML Data
- Binding HTML Elements to XML Data
- Binding HTML Tables to XML Data
- Accessing Individual Data Fields
- Binding HTML Elements to XML Data by Using the XML DSO
- Binding HTML Tables to XML Data by Using the XML DSO
- Searching XML Data by Using a DSO and JavaScript
- Handling Hierarchical XML Data
- Summary
- Q&A
- Workshop
- Day 20. Working with XML and Databases
- XML, Databases, and ASP
- Storing Databases as XML
- Using XPath with a Database
- Introducing XQuery
- Summary
- Q&A
- Workshop
- Day 21. Handling XML in .NET
- Creating and Editing an XML Document in .NET
- From XML to Databases and Back
- Reading and Writing XML in .NET Code
- Using XML Controls to Display Formatted XML
- Creating XML Web Services
- Summary
- Q&A
- Workshop
- Part V. In Review
- Appendix A. Quiz Answers
- Quiz Answers for Day 1
- Quiz Answers for Day 2
- Quiz Answers for Day 3
- Quiz Answers for Day 4
- Quiz Answers for Day 5
- Quiz Answers for Day 6
- Quiz Answers for Day 7
- Quiz Answers for Day 8
- Quiz Answers for Day 9
- Quiz Answers for Day 10
- Quiz Answers for Day 11
- Quiz Answers for Day 12
- Quiz Answers for Day 13
- Quiz Answers for Day 14
- Quiz Answers for Day 15
- Quiz Answers for Day 16
- Quiz Answers for Day 17
- Quiz Answers for Day 18
- Quiz Answers for Day 19
- Quiz Answers for Day 20
- Quiz Answers for Day 21
Recommended Book
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Getting All XML Data from a Document
So that you can see how to work with all the XML data in an XML document at once, you'll take a look at an example that extracts and displays all the data in the XML sample document by using JavaScript. So far, you've only gone after one element or one attribute, but this example will extract and display all the data in the document. Among other things, this will let you handle general XML documents instead of targeting specific elements. This means you will not have to know the document structure before proceeding, and it will also let you determine node types on-the-fly.
In this example you'll use recursion, the technique that allows a method to call itself, to work through an entire document without knowing that document's structure. You'll write a JavaScript method named childLoop to do this; when you're at a node, all you will have to do is loop over all of its child nodes by calling childLoop on them. All you have to do is pass this method a node and an indentation string, and it will display the current node and all of its children, incrementing the indentation by four spaces for each successive generation to make the display onscreen look good. This means you can start by passing the root node to childLoop like this (this method, readXMLData, is called when the user clicks a button labeled Get All the Data in this example):
<HTML>
<HEAD>
<TITLE>
Getting all XML data
</TITLE>
<SCRIPT LANGUAGE="JavaScript">
function readXMLData()
{
xmlDocumentObject = new ActiveXObject("Microsoft.XMLDOM")
xmlDocumentObject.load("ch15_01.xml")
displayDIV.innerHTML = childLoop(xmlDocumentObject, "")
}
.
.
.
Now you need to write the recursive method, childLoop. This method has a node and the current indentation (a string of spaces) passed to it, and the first order of business is to discover what kind of node you're dealing with. You can do that by using the node's nodeType property, like this:
function childLoop(currentNode, indentation)
{
var typeName
switch (currentNode.nodeType) {
case 1:
typeName = "Element"
break
case 2:
typeName = "Attribute"
break
case 3:
typeName = "Text"
break
case 4:
typeName = "CDATA section"
break
case 5:
typeName = "Entity reference"
break
case 6:
typeName = "Entity"
break
case 7:
typeName = "Processing instruction"
break
case 8:
typeName = "Comment"
break
case 9:
typeName = "Document"
break
case 10:
typeName = "Document type"
break
case 11:
typeName = "Document fragment"
break
case 12:
typeName = "Notation"
}
.
.
.
Now you know the type of node and have stored the name of the type, such as "Attribute" or "Text", in the variable called typeName. You can display the type of the current node and its value, if it has a value, like this:
var text
if (currentNode.nodeValue != null) {
text = indentation + "<b>" + typeName +
"</b>: " + currentNode.nodeValue
} else {
text = indentation + "<b>" + typeName +
"</b>: " + currentNode.nodeName
}
That takes care of the node and its value, if it has any. If the node is an element, it can also have attributes, so you loop over them like this:
if (currentNode.attributes != null) {
if (currentNode.attributes.length > 0) {
for (var loopIndex = 0; loopIndex <
currentNode.attributes.length; loopIndex++) {
.
.
.
}
}
}
You can display each attribute and its value like this:
if (currentNode.attributes != null) {
if (currentNode.attributes.length > 0) {
for (var loopIndex = 0; loopIndex <
currentNode.attributes.length; loopIndex++) {
text += " <b>Attribute</b>: " +
currentNode.attributes(loopIndex).nodeName +
" = \"" +
currentNode.attributes(loopIndex).nodeValue
+ "\""
}
}
}
You have completed the display of the current node. Now add a line break and check whether the current node has any children:
text += "<BR>"
if (currentNode.childNodes.length > 0) {
.
.
.
}
return text
}
If the current node has any child nodes, you can loop over those child nodes by calling the childLoop method recursively, like this:
text += "<BR>"
if (currentNode.childNodes.length > 0) {
for (var loopIndex = 0; loopIndex <
currentNode.childNodes.length; loopIndex++) {
text += childLoop(currentNode.childNodes(loopIndex),
indentation + "  ")
}
}
return text
}
Note that here you're increasing the indentation by four spaces by using the HTML nonbreaking space entity, . Otherwise, the browser would normalize multiple indentation spaces into a single space.
At the end of the childLoop method, the code returns the full HTML text to be displayed. The JavaScript in the readXMLData method, which is called when the button in this example is clicked, displays that text in the Web page by using a <DIV> element:
function readXMLData()
{
xmlDocumentObject = new ActiveXObject("Microsoft.XMLDOM")
xmlDocumentObject.load("ch15_01.xml")
displayDIV.innerHTML = childLoop(xmlDocumentObject, "")
}
Listing 15.6 shows all the code for this example, as ch15_06.html. Note that you've added the code to display the button that the user can click, which calls the readXMLData method.
Example 15.6. Getting All XML Data from a Document (ch15_06.html)
<HTML>
<HEAD>
<TITLE>
Getting all XML data
</TITLE>
<SCRIPT LANGUAGE="JavaScript">
function readXMLData()
{
xmlDocumentObject = new ActiveXObject("Microsoft.XMLDOM")
xmlDocumentObject.load("ch15_01.xml")
displayDIV.innerHTML = childLoop(xmlDocumentObject, "")
}
function childLoop(currentNode, indentation)
{
var typeName
switch (currentNode.nodeType) {
case 1:
typeName = "Element"
break
case 2:
typeName = "Attribute"
break
case 3:
typeName = "Text"
break
case 4:
typeName = "CDATA section"
break
case 5:
typeName = "Entity reference"
break
case 6:
typeName = "Entity"
break
case 7:
typeName = "Processing instruction"
break
case 8:
typeName = "Comment"
break
case 9:
typeName = "Document"
break
case 10:
typeName = "Document type"
break
case 11:
typeName = "Document fragment"
break
case 12:
typeName = "Notation"
}
var text
if (currentNode.nodeValue != null) {
text = indentation + "<b>" + typeName +
"</b>: " + currentNode.nodeValue
} else {
text = indentation + "<b>" + typeName +
"</b>: " + currentNode.nodeName
}
if (currentNode.attributes != null) {
if (currentNode.attributes.length > 0) {
for (var loopIndex = 0; loopIndex <
currentNode.attributes.length; loopIndex++) {
text += " <b>Attribute</b>: " +
currentNode.attributes(loopIndex).nodeName +
" = \"" +
currentNode.attributes(loopIndex).nodeValue
+ "\""
}
}
}
text += "<BR>"
if (currentNode.childNodes.length > 0) {
for (var loopIndex = 0; loopIndex <
currentNode.childNodes.length; loopIndex++) {
text += childLoop(currentNode.childNodes(loopIndex),
indentation + "  ")
}
}
return text
}
</SCRIPT>
</HEAD>
<BODY>
<H1>
Getting all XML data
</H1>
<INPUT TYPE="BUTTON" VALUE="Get all the data"
onClick = "readXMLData()">
<DIV ID="displayDIV"></DIV>
</BODY>
</HTML>
You can see the results of this JavaScript in Figure 15.4. As you can see, by using JavaScript and the W3C DOM, you've been able to parse an entire XML document and list all of its data independently of the document's structure. Not bad!
)
Figure 15.4 Parsing an entire XML document.