Session IV
Chapter 3 – XPath Patterns & Expressions
Chapter 4 – XPath Functions
Chapter 15 – XPath 2.0
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Outline
 Introduction
 XPath Functions
 XPath 1.0
 Nodes
 Syntax
 Nodes Relationship /
Axes
 Operators
 XPath 2.0
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Introduction
 XPath is a syntax for defining parts of an XML document
 XPath uses path expressions to navigate in XML
documents
 XPath contains a library of standard functions
 XPath is a major element in XSLT
 XPath is a W3C recommendation
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Introduction
 XPath Path Expressions
 Select nodes or node-sets
 XPath Standard Functions
 Over 100 built-in functions
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Chapter 3 - XPath Nodes
 Seven Kinds of Nodes:
 Element
 Attribute
 Text
 Namespace
 Processing-instruction
 Comment
 Document
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XPath Node Relationship / Axes
 Node Relationships / Axes:
 Parent
 Children
 Siblings
 Ancestors
 Descendants
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XPath Operators
 XPath Operators
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XPath Syntax
Path Expression
Description
nodename
Selects all nodes with the name "nodename"
/
Selects from the root node
//
Selects nodes in the document from the current node that match
the selection no matter where they are
.
Selects the current node
..
Selects the parent of the current node
@
Selects attributes
Expression
Description
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Chapter 4 - XPath Functions
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Accessor
Error and Trace
Numeric
String
AnyURI
Boolean
Duration/Date/Time
QName
Node
Sequence
Context
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Chapter 15 - XPath 2.0
 XQuery/XPath Data Model (XDM)
 Supports XML Schemas
 XPath Sequences
 Comma Separated ordered lists of items.
 Defined by a node or atomic value.
 Can have duplicates
 Flat Structure
 Can Take Predicates - Filters [ ]
 Can be used in Loops
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XPath 2.0 Processes
 Average Values
 Looping Over Sequences
 Min – Max
 Using Date and Time
 Formatting Strings
 Writing Comments
 Testing Conditions
 Processing Non-XML
 Quantifying a Condition
Input
 Removing Duplicate Items
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Review
 Introduction
 XPath Functions
 XPath 1.0
 XPath 2.0
 Nodes
 Syntax
 Nodes Relationship /
Axes
Next - Chapters 12 & 13 XML Namespaces
 Operators
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