XPathProcessor Class Reference

#include <XPathProcessor.h>

Public Member Functions
	XPathProcessor ()
	Default constructor.
	XPathProcessor (SaxonProcessor *proc, std::string cwd="")
	Constructor with the SaxonProcessor supplied.
	XPathProcessor (const XPathProcessor &other)
void	setBaseURI (const char *uriStr)
	Set the static base URI for XPath expressions compiled using this XPathCompiler.
XdmValue *	evaluate (const char *xpathStr)
	Compile and evaluate an XPath expression.
XdmItem *	evaluateSingle (const char *xpathStr)
	Compile and evaluate an XPath expression. The result is expected to be a single XdmItem or nullptr.
void	setContextItem (XdmItem *item)
void	setcwd (const char *cwd)
void	setContextFile (const char *filename)
bool	effectiveBooleanValue (const char *xpathStr)
	Evaluate the XPath expression, returning the effective boolean value of the result.
void	setParameter (const char *name, XdmValue *value)
bool	removeParameter (const char *name)
void	setProperty (const char *name, const char *value)
	Set a property specific to the processor in use.
void	declareNamespace (const char *prefix, const char *uri)
	Declare a namespace binding as part of the static context for XPath expressions compiled using this XPathCompiler.
void	declareVariable (const char *name)
	Declare a variable as part of the static context for XPath expressions compiled using this XPathCompiler.
void	setBackwardsCompatible (bool option)
	Say whether XPath 1.0 backwards compatibility mode is to be used.
void	setCaching (bool caching)
	Say whether the compiler should maintain a cache of compiled expressions.
void	importSchemaNamespace (const char *uri)
	Import a schema namespace.
std::map< std::string, XdmValue * > &	getParameters ()
std::map< std::string, std::string > &	getProperties ()
void	clearParameters (bool deleteValues=false)
void	clearProperties ()
bool	exceptionOccurred ()
void	exceptionClear ()
	Clear any exception thrown.
const char *	getErrorMessage ()
	Get the first error message if there are any errors.
const char *	getErrorCode ()
	Get the first error code if there are any errors.
SaxonApiException *	getException ()
	Get the SaxonApiException object created when we have an error.

Detailed Description

An XPathProcessor represents a factory to compile, load and execute XPath expressions.

Constructor & Destructor Documentation

XPathProcessor() [1/3]

XPathProcessor::XPathProcessor

(

)

Default constructor.

Creates a Saxon-HE XPath product

XPathProcessor() [2/3]

XPathProcessor::XPathProcessor	(	SaxonProcessor *	proc,
		std::string	cwd = ""
	)

Constructor with the SaxonProcessor supplied.

Parameters

proc	- Pointer to the SaxonProcessor object
cwd	- The current working directory

XPathProcessor() [3/3]

XPathProcessor::XPathProcessor

(

const XPathProcessor &

other

)

XPathProcessor copy constructor.

Parameters

other

- XPathProcessor

Member Function Documentation

clearParameters()

void XPathProcessor::clearParameters

(

bool

deleteValues = false

)

Clear parameter values set. Default behaviour (false) is to leave XdmValues in memory. Individual pointers to XdmValue objects have to be deleted in the calling program.

Parameters

deleteValues

- if true then XdmValues are deleted

clearProperties()

void XPathProcessor::clearProperties

(

)

Clear property values set

declareNamespace()

void XPathProcessor::declareNamespace	(	const char *	prefix,
		const char *	uri
	)

Declare a namespace binding as part of the static context for XPath expressions compiled using this XPathCompiler.

Parameters

prefix	The namespace prefix. If the value is a zero-length string, this method sets the default namespace for elements and types.
uri	The namespace URI. It is possible to specify a zero-length string to "undeclare" a namespace; in this case the prefix will not be available for use, except in the case where the prefix is also a zero length string, in which case the absence of a prefix implies that the name is in no namespace. Assume the prefix or uri is nullptr.

declareVariable()

void XPathProcessor::declareVariable

(

const char *

name

)

Declare a variable as part of the static context for XPath expressions compiled using this XPathCompiler.

It is an error for the XPath expression to refer to a variable unless it has been declared. This method declares the existence of the variable, but it does not bind any value to the variable; that is done later, when the XPath expression is evaluated. The variable is allowed to have any type (that is, the required type is item()*).

Parameters

name	The name of the variable, expressions as a clark name string

effectiveBooleanValue()

bool XPathProcessor::effectiveBooleanValue

(

const char *

xpathStr

)

Evaluate the XPath expression, returning the effective boolean value of the result.

Parameters

xpathStr

- supplied as a character string

Returns

bool

evaluate()

XdmValue * XPathProcessor::evaluate

(

const char *

xpathStr

)

Compile and evaluate an XPath expression.

Parameters

xpathStr

- supplied as a character string

Returns

XdmValue

evaluateSingle()

XdmItem * XPathProcessor::evaluateSingle

(

const char *

xpathStr

)

Compile and evaluate an XPath expression. The result is expected to be a single XdmItem or nullptr.

Parameters

xpathStr

- supplied as a character string

Returns

XdmItem - XdmItem object or nullptr if the expression returns an empty sequence. If the expression returns a sequence of more than one item, any items after the first are ignored.

exceptionOccurred()

bool XPathProcessor::exceptionOccurred

(

)

Checks for pending exceptions without creating a local reference to the exception object

Returns

bool - true when there is a pending exception; otherwise return false Checks for pending exceptions without creating a local reference to the exception object

bool - true when there is a pending exception; otherwise return false

getErrorCode()

const char * XPathProcessor::getErrorCode

(

)

Get the first error code if there are any errors.

After the execution of the XPath expression there may be a number of errors reported against it.

Returns

char* - The error code of the exception.

getErrorMessage()

const char * XPathProcessor::getErrorMessage

(

)

Get the first error message if there are any errors.

An XPath expression may have a number of errors reported against it.

Returns

char* - The message of the exception

getException()

SaxonApiException * XPathProcessor::getException

(

)

Get the SaxonApiException object created when we have an error.

After the execution of the processor if there is an error, then a SaxonApiException is created. NULL returned if there is no error.

Returns

SaxonApiException object of the exception thrown.

getParameters()

std::map< std::string, XdmValue * > & XPathProcessor::getParameters

(

)

Get all parameters as a std::map

getProperties()

std::map< std::string, std::string > & XPathProcessor::getProperties

(

)

Get all properties as a std::map

importSchemaNamespace()

void XPathProcessor::importSchemaNamespace

(

const char *

uri

)

Import a schema namespace.

Here we add the element and attribute declarations and type definitions contained in a given namespace to the static context for the XPath expression.

This method will not cause the schema to be loaded. This method will not fail if the schema has not been loaded (but in that case the set of declarations and definitions made available to the XPath expression is empty). The schema document for the specified namespace may be loaded before or after this method is called.

This method does not bind a prefix to the namespace. That must be done separately, using the declareNamespace(String, String) method.

Parameters

uri	The schema namespace to be imported. To import declarations in a no-namespace schema, supply a zero-length string.

removeParameter()

bool XPathProcessor::removeParameter

(

const char *

name

)

Remove a parameter (name, value) pair

Parameters

name	of the parameter

Returns

bool - outcome of the removal

setBackwardsCompatible()

void XPathProcessor::setBackwardsCompatible

(

bool

option

)

Say whether XPath 1.0 backwards compatibility mode is to be used.

In backwards compatibility mode, more implicit type conversions are allowed in XPath expressions, for example it is possible to compare a number with a string. The default is false (backwards compatibility mode is off).

Parameters

option

true if XPath 1.0 backwards compatibility is to be enabled, false if it is to be disabled.

setBaseURI()

void XPathProcessor::setBaseURI

(

const char *

uriStr

)

Set the static base URI for XPath expressions compiled using this XPathCompiler.

The base URI is part of the static context, and is used to resolve any relative URIs appearing within an XPath expression, for example a relative URI passed as an argument to the doc() function. If no static base URI is supplied, then the current working directory is used.

Parameters

uriStr

setCaching()

void XPathProcessor::setCaching

(

bool

caching

)

Say whether the compiler should maintain a cache of compiled expressions.

Parameters

caching

if set to true, caching of compiled expressions is enabled. If set to false, any existing cache is cleared, and future compiled expressions will not be cached until caching is re-enabled. The cache is also cleared (but without disabling future caching) if any method is called that changes the static context for compiling expressions, for example declareVariable(QName) or declareNamespace(String, String).

setContextFile()

void XPathProcessor::setContextFile

(

const char *

filename

)

Set the context item from file

setContextItem()

void XPathProcessor::setContextItem

(

XdmItem *

item

)

Set the context item

setcwd()

void XPathProcessor::setcwd

(

const char *

cwd

)

set the current working directory

setParameter()

void XPathProcessor::setParameter	(	const char *	name,
		XdmValue *	value
	)

Set a parameter value used in the query

Parameters

name	of the parameter, as a string. For namespaced parameter use the JAXP solution i.e. "{uri}name"
value	of the query parameter, or nullptr to clear a previously set value

setProperty()

void XPathProcessor::setProperty	(	const char *	name,
		const char *	value
	)

Set a property specific to the processor in use.

XPathProcessor: set serialization properties (names start with '!' i.e. name "!method" -> "xml") 'o':outfile name, 's': context item supplied as file name

Parameters

name	of the property
value	of the property

---

The documentation for this class was generated from the following files:

• Saxon.C.API/XPathProcessor.h
• Saxon.C.API/XPathProcessor.cpp