xmlwriter		API documentation		The XML C parser and toolkit of Gnome	xpathInternals

API for the XML Path Language implementation XML Path Language implementation XPath is a language for addressing parts of an XML document, designed to be used by both XSLT and XPointer

Table of Contents

#define XML_XPATH_CHECKNS

#define XML_XPATH_NOVAR

#define xmlXPathNodeSetGetLength

#define xmlXPathNodeSetIsEmpty

#define xmlXPathNodeSetItem

Structure xmlNodeSet
struct _xmlNodeSet

Typedef xmlNodeSet * xmlNodeSetPtr

Structure xmlXPathAxis
struct _xmlXPathAxis

Typedef xmlXPathAxis * xmlXPathAxisPtr

Structure xmlXPathCompExpr
struct _xmlXPathCompExpr
The content of this structure is not made public by the API.

Typedef xmlXPathCompExpr * xmlXPathCompExprPtr

Structure xmlXPathContext
struct _xmlXPathContext

Typedef xmlXPathContext * xmlXPathContextPtr

Enum xmlXPathError

Typedef xmlXPathFunct * xmlXPathFuncPtr

Structure xmlXPathFunct
struct _xmlXPathFunct

Structure xmlXPathObject
struct _xmlXPathObject

Typedef xmlXPathObject * xmlXPathObjectPtr

Enum xmlXPathObjectType

Structure xmlXPathParserContext
struct _xmlXPathParserContext

Typedef xmlXPathParserContext * xmlXPathParserContextPtr

Structure xmlXPathType
struct _xmlXPathType

Typedef xmlXPathType * xmlXPathTypePtr

Structure xmlXPathVariable
struct _xmlXPathVariable

Typedef xmlXPathVariable * xmlXPathVariablePtr

Function type: xmlXPathAxisFunc
xmlXPathObjectPtr	xmlXPathAxisFunc	(xmlXPathParserContextPtr ctxt, 
						 xmlXPathObjectPtr cur)

double	xmlXPathCastBooleanToNumber	(int val)

xmlChar *	xmlXPathCastBooleanToString	(int val)

int	xmlXPathCastNodeSetToBoolean	(xmlNodeSetPtr ns)

double	xmlXPathCastNodeSetToNumber	(xmlNodeSetPtr ns)

xmlChar *	xmlXPathCastNodeSetToString	(xmlNodeSetPtr ns)

double	xmlXPathCastNodeToNumber	(xmlNodePtr node)

xmlChar *	xmlXPathCastNodeToString	(xmlNodePtr node)

int	xmlXPathCastNumberToBoolean	(double val)

xmlChar *	xmlXPathCastNumberToString	(double val)

int	xmlXPathCastStringToBoolean	(const xmlChar * val)

double	xmlXPathCastStringToNumber	(const xmlChar * val)

int	xmlXPathCastToBoolean		(xmlXPathObjectPtr val)

double	xmlXPathCastToNumber		(xmlXPathObjectPtr val)

xmlChar *	xmlXPathCastToString	(xmlXPathObjectPtr val)

int	xmlXPathCmpNodes		(xmlNodePtr node1, 
					 xmlNodePtr node2)

xmlXPathCompExprPtr	xmlXPathCompile	(const xmlChar * str)

xmlXPathObjectPtr	xmlXPathCompiledEval	(xmlXPathCompExprPtr comp, 
						 xmlXPathContextPtr ctx)

int	xmlXPathCompiledEvalToBoolean	(xmlXPathCompExprPtr comp, 
					 xmlXPathContextPtr ctxt)

int	xmlXPathContextSetCache		(xmlXPathContextPtr ctxt, 
					 int active, 
					 int value, 
					 int options)

xmlXPathObjectPtr	xmlXPathConvertBoolean	(xmlXPathObjectPtr val)

Function type: xmlXPathConvertFunc
int	xmlXPathConvertFunc		(xmlXPathObjectPtr obj, 
					 int type)

xmlXPathObjectPtr	xmlXPathConvertNumber	(xmlXPathObjectPtr val)

xmlXPathObjectPtr	xmlXPathConvertString	(xmlXPathObjectPtr val)

xmlXPathCompExprPtr	xmlXPathCtxtCompile	(xmlXPathContextPtr ctxt, 
						 const xmlChar * str)

xmlXPathObjectPtr	xmlXPathEval	(const xmlChar * str, 
					 xmlXPathContextPtr ctx)

xmlXPathObjectPtr	xmlXPathEvalExpression	(const xmlChar * str, 
						 xmlXPathContextPtr ctxt)

Function type: xmlXPathEvalFunc
void	xmlXPathEvalFunc		(xmlXPathParserContextPtr ctxt, 
					 int nargs)

int	xmlXPathEvalPredicate		(xmlXPathContextPtr ctxt, 
					 xmlXPathObjectPtr res)

void	xmlXPathFreeCompExpr		(xmlXPathCompExprPtr comp)

void	xmlXPathFreeContext		(xmlXPathContextPtr ctxt)

void	xmlXPathFreeNodeSet		(xmlNodeSetPtr obj)

void	xmlXPathFreeNodeSetList		(xmlXPathObjectPtr obj)

void	xmlXPathFreeObject		(xmlXPathObjectPtr obj)

Function type: xmlXPathFuncLookupFunc
xmlXPathFunction	xmlXPathFuncLookupFunc	(void * ctxt, 
						 const xmlChar * name, 
						 const xmlChar * ns_uri)

Function type: xmlXPathFunction
void	xmlXPathFunction		(xmlXPathParserContextPtr ctxt, 
					 int nargs)

void	xmlXPathInit			(void)

int	xmlXPathIsInf			(double val)

int	xmlXPathIsNaN			(double val)

xmlXPathContextPtr	xmlXPathNewContext	(xmlDocPtr doc)

xmlXPathObjectPtr	xmlXPathNodeEval	(xmlNodePtr node, 
						 const xmlChar * str, 
						 xmlXPathContextPtr ctx)

xmlNodeSetPtr	xmlXPathNodeSetCreate	(xmlNodePtr val)

xmlXPathObjectPtr	xmlXPathObjectCopy	(xmlXPathObjectPtr val)

long	xmlXPathOrderDocElems		(xmlDocPtr doc)

int	xmlXPathSetContextNode		(xmlNodePtr node, 
					 xmlXPathContextPtr ctx)

Function type: xmlXPathVariableLookupFunc
xmlXPathObjectPtr	xmlXPathVariableLookupFunc	(void * ctxt, 
							 const xmlChar * name, 
							 const xmlChar * ns_uri)

Description

Macro: XML_XPATH_CHECKNS

#define XML_XPATH_CHECKNS

check namespaces at compilation

Macro: XML_XPATH_NOVAR

#define XML_XPATH_NOVAR

forbid variables in expression

Macro: xmlXPathNodeSetGetLength

#define xmlXPathNodeSetGetLength

Implement a functionality similar to the DOM NodeList.length. Returns the number of nodes in the node-set.

Macro: xmlXPathNodeSetIsEmpty

#define xmlXPathNodeSetIsEmpty

Checks whether @ns is empty or not. Returns %TRUE if @ns is an empty node-set.

Macro: xmlXPathNodeSetItem

#define xmlXPathNodeSetItem

Implements a functionality similar to the DOM NodeList.item(). Returns the xmlNodePtr at the given @index in @ns or NULL if @index is out of range (0 to length-1)

Structure xmlNodeSet

Structure xmlNodeSet
struct _xmlNodeSet {
    int	nodeNr	: number of nodes in the set
    int	nodeMax	: size of the array as allocated
    xmlNodePtr *	nodeTab	: array of nodes in no particular order @
}

Structure xmlXPathAxis

Structure xmlXPathAxis
struct _xmlXPathAxis {
    const xmlChar *	name	: the axis name
    xmlXPathAxisFunc	func	: the search function
}

Structure xmlXPathCompExpr

Structure xmlXPathCompExpr
struct _xmlXPathCompExpr {
The content of this structure is not made public by the API.
}

Structure xmlXPathContext

Structure xmlXPathContext
struct _xmlXPathContext {
    xmlDocPtr	doc	: The current document
    xmlNodePtr	node	: The current node
    int	nb_variables_unused	: unused (hash table)
    int	max_variables_unused	: unused (hash table)
    xmlHashTablePtr	varHash	: Hash table of defined variables
    int	nb_types	: number of defined types
    int	max_types	: max number of types
    xmlXPathTypePtr	types	: Array of defined types
    int	nb_funcs_unused	: unused (hash table)
    int	max_funcs_unused	: unused (hash table)
    xmlHashTablePtr	funcHash	: Hash table of defined funcs
    int	nb_axis	: number of defined axis
    int	max_axis	: max number of axis
    xmlXPathAxisPtr	axis	: Array of defined axis the namespace nod
    xmlNsPtr *	namespaces	: Array of namespaces
    int	nsNr	: number of namespace in scope
    void *	user	: function to free extra variables
    int	contextSize	: the context size
    int	proximityPosition	: the proximity position extra stuff for
    int	xptr	: is this an XPointer context?
    xmlNodePtr	here	: for here()
    xmlNodePtr	origin	: for origin() the set of namespace decla
    xmlHashTablePtr	nsHash	: The namespaces hash table
    xmlXPathVariableLookupFunc	varLookupFunc	: variable lookup func
    void *	varLookupData	: variable lookup data Possibility to lin
    void *	extra	: needed for XSLT The function name and U
    const xmlChar *	function
    const xmlChar *	functionURI	: function lookup function and data
    xmlXPathFuncLookupFunc	funcLookupFunc	: function lookup func
    void *	funcLookupData	: function lookup data temporary namespac
    xmlNsPtr *	tmpNsList	: Array of namespaces
    int	tmpNsNr	: number of namespaces in scope error rep
    void *	userData	: user specific data block
    xmlStructuredErrorFunc	error	: the callback in case of errors
    xmlError	lastError	: the last error
    xmlNodePtr	debugNode	: the source node XSLT dictionary
    xmlDictPtr	dict	: dictionary if any
    int	flags	: flags to control compilation Cache for
    void *	cache	: Resource limits
    unsigned long	opLimit
    unsigned long	opCount
    int	depth
}

Enum xmlXPathError

Enum xmlXPathError {
    XPATH_EXPRESSION_OK = 0
    XPATH_NUMBER_ERROR = 1
    XPATH_UNFINISHED_LITERAL_ERROR = 2
    XPATH_START_LITERAL_ERROR = 3
    XPATH_VARIABLE_REF_ERROR = 4
    XPATH_UNDEF_VARIABLE_ERROR = 5
    XPATH_INVALID_PREDICATE_ERROR = 6
    XPATH_EXPR_ERROR = 7
    XPATH_UNCLOSED_ERROR = 8
    XPATH_UNKNOWN_FUNC_ERROR = 9
    XPATH_INVALID_OPERAND = 10
    XPATH_INVALID_TYPE = 11
    XPATH_INVALID_ARITY = 12
    XPATH_INVALID_CTXT_SIZE = 13
    XPATH_INVALID_CTXT_POSITION = 14
    XPATH_MEMORY_ERROR = 15
    XPTR_SYNTAX_ERROR = 16
    XPTR_RESOURCE_ERROR = 17
    XPTR_SUB_RESOURCE_ERROR = 18
    XPATH_UNDEF_PREFIX_ERROR = 19
    XPATH_ENCODING_ERROR = 20
    XPATH_INVALID_CHAR_ERROR = 21
    XPATH_INVALID_CTXT = 22
    XPATH_STACK_ERROR = 23
    XPATH_FORBID_VARIABLE_ERROR = 24
    XPATH_OP_LIMIT_EXCEEDED = 25
    XPATH_RECURSION_LIMIT_EXCEEDED = 26
}

Structure xmlXPathFunct

Structure xmlXPathFunct
struct _xmlXPathFunct {
    const xmlChar *	name	: the function name
    xmlXPathEvalFunc	func	: the evaluation function
}

Structure xmlXPathObject

Structure xmlXPathObject
struct _xmlXPathObject {
    xmlXPathObjectType	type
    xmlNodeSetPtr	nodesetval
    int	boolval
    double	floatval
    xmlChar *	stringval
    void *	user
    int	index
    void *	user2
    int	index2
}

Enum xmlXPathObjectType

Enum xmlXPathObjectType {
    XPATH_UNDEFINED = 0
    XPATH_NODESET = 1
    XPATH_BOOLEAN = 2
    XPATH_NUMBER = 3
    XPATH_STRING = 4
    XPATH_POINT = 5
    XPATH_RANGE = 6
    XPATH_LOCATIONSET = 7
    XPATH_USERS = 8
    XPATH_XSLT_TREE = 9 : An XSLT value tree, non modifiable
}

Structure xmlXPathParserContext

Structure xmlXPathParserContext
struct _xmlXPathParserContext {
    const xmlChar *	cur	: the current char being parsed
    const xmlChar *	base	: the full expression
    int	error	: error code
    xmlXPathContextPtr	context	: the evaluation context
    xmlXPathObjectPtr	value	: the current value
    int	valueNr	: number of values stacked
    int	valueMax	: max number of values stacked
    xmlXPathObjectPtr *	valueTab	: stack of values
    xmlXPathCompExprPtr	comp	: the precompiled expression
    int	xptr	: it this an XPointer expression
    xmlNodePtr	ancestor	: used for walking preceding axis
    int	valueFrame	: used to limit Pop on the stack
}

Structure xmlXPathType

Structure xmlXPathType
struct _xmlXPathType {
    const xmlChar *	name	: the type name
    xmlXPathConvertFunc	func	: the conversion function
}

Structure xmlXPathVariable

Structure xmlXPathVariable
struct _xmlXPathVariable {
    const xmlChar *	name	: the variable name
    xmlXPathObjectPtr	value	: the value
}

Function type: xmlXPathAxisFunc

Function type: xmlXPathAxisFunc
xmlXPathObjectPtr	xmlXPathAxisFunc	(xmlXPathParserContextPtr ctxt, 
						 xmlXPathObjectPtr cur)

An axis traversal function. To traverse an axis, the engine calls the first time with cur == NULL and repeat until the function returns NULL indicating the end of the axis traversal.

Function: xmlXPathCastBooleanToNumber

double	xmlXPathCastBooleanToNumber	(int val)

Converts a boolean to its number value

Function: xmlXPathCastBooleanToString

xmlChar *	xmlXPathCastBooleanToString	(int val)

Converts a boolean to its string value.

Function: xmlXPathCastNodeSetToBoolean

int	xmlXPathCastNodeSetToBoolean	(xmlNodeSetPtr ns)

Converts a node-set to its boolean value

Function: xmlXPathCastNodeSetToNumber

double	xmlXPathCastNodeSetToNumber	(xmlNodeSetPtr ns)

Converts a node-set to its number value

Function: xmlXPathCastNodeSetToString

xmlChar *	xmlXPathCastNodeSetToString	(xmlNodeSetPtr ns)

Converts a node-set to its string value.

Function: xmlXPathCastNodeToNumber

double	xmlXPathCastNodeToNumber	(xmlNodePtr node)

Converts a node to its number value

Function: xmlXPathCastNodeToString

xmlChar *	xmlXPathCastNodeToString	(xmlNodePtr node)

Converts a node to its string value.

Function: xmlXPathCastNumberToBoolean

int	xmlXPathCastNumberToBoolean	(double val)

Converts a number to its boolean value

Function: xmlXPathCastNumberToString

xmlChar *	xmlXPathCastNumberToString	(double val)

Converts a number to its string value.

Function: xmlXPathCastStringToBoolean

int	xmlXPathCastStringToBoolean	(const xmlChar * val)

Converts a string to its boolean value

Function: xmlXPathCastStringToNumber

double	xmlXPathCastStringToNumber	(const xmlChar * val)

Converts a string to its number value

Function: xmlXPathCastToBoolean

int	xmlXPathCastToBoolean		(xmlXPathObjectPtr val)

Converts an XPath object to its boolean value

Function: xmlXPathCastToNumber

double	xmlXPathCastToNumber		(xmlXPathObjectPtr val)

Converts an XPath object to its number value

Function: xmlXPathCastToString

xmlChar *	xmlXPathCastToString	(xmlXPathObjectPtr val)

Converts an existing object to its string() equivalent

Function: xmlXPathCmpNodes

int	xmlXPathCmpNodes		(xmlNodePtr node1, 
					 xmlNodePtr node2)

Compare two nodes w.r.t document order

Function: xmlXPathCompile

xmlXPathCompExprPtr	xmlXPathCompile	(const xmlChar * str)

Compile an XPath expression

Function: xmlXPathCompiledEval

xmlXPathObjectPtr	xmlXPathCompiledEval	(xmlXPathCompExprPtr comp, 
						 xmlXPathContextPtr ctx)

Evaluate the Precompiled XPath expression in the given context.

Function: xmlXPathCompiledEvalToBoolean

int	xmlXPathCompiledEvalToBoolean	(xmlXPathCompExprPtr comp, 
					 xmlXPathContextPtr ctxt)

Applies the XPath boolean() function on the result of the given compiled expression.

Function: xmlXPathContextSetCache

int	xmlXPathContextSetCache		(xmlXPathContextPtr ctxt, 
					 int active, 
					 int value, 
					 int options)

Creates/frees an object cache on the XPath context. If activates XPath objects (xmlXPathObject) will be cached internally to be reused. @options: 0: This will set the XPath object caching: @value: This will set the maximum number of XPath objects to be cached per slot There are 5 slots for: node-set, string, number, boolean, and misc objects. Use <0 for the default number (100). Other values for @options have currently no effect.

Function: xmlXPathConvertBoolean

xmlXPathObjectPtr	xmlXPathConvertBoolean	(xmlXPathObjectPtr val)

Converts an existing object to its boolean() equivalent

Function type: xmlXPathConvertFunc

Function type: xmlXPathConvertFunc
int	xmlXPathConvertFunc		(xmlXPathObjectPtr obj, 
					 int type)

A conversion function is associated to a type and used to cast the new type to primitive values.

Function: xmlXPathConvertNumber

xmlXPathObjectPtr	xmlXPathConvertNumber	(xmlXPathObjectPtr val)

Converts an existing object to its number() equivalent

Function: xmlXPathConvertString

xmlXPathObjectPtr	xmlXPathConvertString	(xmlXPathObjectPtr val)

Converts an existing object to its string() equivalent

Function: xmlXPathCtxtCompile

xmlXPathCompExprPtr	xmlXPathCtxtCompile	(xmlXPathContextPtr ctxt, 
						 const xmlChar * str)

Compile an XPath expression

Function: xmlXPathEval

xmlXPathObjectPtr	xmlXPathEval	(const xmlChar * str, 
					 xmlXPathContextPtr ctx)

Evaluate the XPath Location Path in the given context.

Function: xmlXPathEvalExpression

xmlXPathObjectPtr	xmlXPathEvalExpression	(const xmlChar * str, 
						 xmlXPathContextPtr ctxt)

Alias for xmlXPathEval().

Function type: xmlXPathEvalFunc

Function type: xmlXPathEvalFunc
void	xmlXPathEvalFunc		(xmlXPathParserContextPtr ctxt, 
					 int nargs)

An XPath evaluation function, the parameters are on the XPath context stack.

Function: xmlXPathEvalPredicate

int	xmlXPathEvalPredicate		(xmlXPathContextPtr ctxt, 
					 xmlXPathObjectPtr res)

Evaluate a predicate result for the current node. A PredicateExpr is evaluated by evaluating the Expr and converting the result to a boolean. If the result is a number, the result will be converted to true if the number is equal to the position of the context node in the context node list (as returned by the position function) and will be converted to false otherwise; if the result is not a number, then the result will be converted as if by a call to the boolean function.

Function: xmlXPathFreeCompExpr

void	xmlXPathFreeCompExpr		(xmlXPathCompExprPtr comp)

Free up the memory allocated by @comp

Function: xmlXPathFreeContext

void	xmlXPathFreeContext		(xmlXPathContextPtr ctxt)

Free up an xmlXPathContext

Function: xmlXPathFreeNodeSet

void	xmlXPathFreeNodeSet		(xmlNodeSetPtr obj)

Free the NodeSet compound (not the actual nodes !).

Function: xmlXPathFreeNodeSetList

void	xmlXPathFreeNodeSetList		(xmlXPathObjectPtr obj)

Free up the xmlXPathObjectPtr @obj but don't deallocate the objects in the list contrary to xmlXPathFreeObject().

Function: xmlXPathFreeObject

void	xmlXPathFreeObject		(xmlXPathObjectPtr obj)

Free up an xmlXPathObjectPtr object.

Function type: xmlXPathFuncLookupFunc

Function type: xmlXPathFuncLookupFunc
xmlXPathFunction	xmlXPathFuncLookupFunc	(void * ctxt, 
						 const xmlChar * name, 
						 const xmlChar * ns_uri)

Prototype for callbacks used to plug function lookup in the XPath engine.

Function type: xmlXPathFunction

Function type: xmlXPathFunction
void	xmlXPathFunction		(xmlXPathParserContextPtr ctxt, 
					 int nargs)

An XPath function. The arguments (if any) are popped out from the context stack and the result is pushed on the stack.

Function: xmlXPathInit

void	xmlXPathInit			(void)

Initialize the XPath environment

Function: xmlXPathIsInf

int	xmlXPathIsInf			(double val)

Function: xmlXPathIsNaN

int	xmlXPathIsNaN			(double val)

Function: xmlXPathNewContext

xmlXPathContextPtr	xmlXPathNewContext	(xmlDocPtr doc)

Create a new xmlXPathContext

Function: xmlXPathNodeEval

xmlXPathObjectPtr	xmlXPathNodeEval	(xmlNodePtr node, 
						 const xmlChar * str, 
						 xmlXPathContextPtr ctx)

Evaluate the XPath Location Path in the given context. The node 'node' is set as the context node. The context node is not restored.

Function: xmlXPathNodeSetCreate

xmlNodeSetPtr	xmlXPathNodeSetCreate	(xmlNodePtr val)

Create a new xmlNodeSetPtr of type double and of value @val

Function: xmlXPathObjectCopy

xmlXPathObjectPtr	xmlXPathObjectCopy	(xmlXPathObjectPtr val)

allocate a new copy of a given object

Function: xmlXPathOrderDocElems

long	xmlXPathOrderDocElems		(xmlDocPtr doc)

Call this routine to speed up XPath computation on static documents. This stamps all the element nodes with the document order Like for line information, the order is kept in the element->content field, the value stored is actually - the node number (starting at -1) to be able to differentiate from line numbers.

Function: xmlXPathSetContextNode

int	xmlXPathSetContextNode		(xmlNodePtr node, 
					 xmlXPathContextPtr ctx)

Sets 'node' as the context node. The node must be in the same document as that associated with the context.

Function type: xmlXPathVariableLookupFunc

Function type: xmlXPathVariableLookupFunc
xmlXPathObjectPtr	xmlXPathVariableLookupFunc	(void * ctxt, 
							 const xmlChar * name, 
							 const xmlChar * ns_uri)

Prototype for callbacks used to plug variable lookup in the XPath engine.

Daniel Veillard