deps/src/libxml2-2.9.1/doc/devhelp/libxml2-xpath.html
| | | | | libxml2 Reference Manual |
xpath - XML Path Language implementation
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
Author(s): Daniel Veillard
#define[xmlXPathNodeSetGetLength](#xmlXPathNodeSetGetLength)(ns);
#define[XML\_XPATH\_CHECKNS](#XML_XPATH_CHECKNS);
#define[XML\_XPATH\_NOVAR](#XML_XPATH_NOVAR);
#define[xmlXPathNodeSetItem](#xmlXPathNodeSetItem)(ns, index);
#define[xmlXPathNodeSetIsEmpty](#xmlXPathNodeSetIsEmpty)(ns);
typedef enum[xmlXPathObjectType](#xmlXPathObjectType);
typedef[xmlXPathVariable](libxml2-xpath.html#xmlXPathVariable)*[xmlXPathVariablePtr](#xmlXPathVariablePtr);
typedef struct _xmlXPathContext[xmlXPathContext](#xmlXPathContext);
typedef enum[xmlXPathError](#xmlXPathError);
typedef struct _xmlXPathFunct[xmlXPathFunct](#xmlXPathFunct);
typedef[xmlXPathType](libxml2-xpath.html#xmlXPathType)*[xmlXPathTypePtr](#xmlXPathTypePtr);
typedef struct _xmlXPathType[xmlXPathType](#xmlXPathType);
typedef[xmlNodeSet](libxml2-xpath.html#xmlNodeSet)*[xmlNodeSetPtr](#xmlNodeSetPtr);
typedef[xmlXPathFunct](libxml2-xpath.html#xmlXPathFunct)*[xmlXPathFuncPtr](#xmlXPathFuncPtr);
typedef[xmlXPathCompExpr](libxml2-xpath.html#xmlXPathCompExpr)*[xmlXPathCompExprPtr](#xmlXPathCompExprPtr);
typedef struct _xmlXPathObject[xmlXPathObject](#xmlXPathObject);
typedef struct _xmlXPathCompExpr[xmlXPathCompExpr](#xmlXPathCompExpr);
typedef[xmlXPathContext](libxml2-xpath.html#xmlXPathContext)*[xmlXPathContextPtr](#xmlXPathContextPtr);
typedef[xmlXPathParserContext](libxml2-xpath.html#xmlXPathParserContext)*[xmlXPathParserContextPtr](#xmlXPathParserContextPtr);
typedef struct _xmlNodeSet[xmlNodeSet](#xmlNodeSet);
typedef struct _xmlXPathVariable[xmlXPathVariable](#xmlXPathVariable);
typedef[xmlXPathObject](libxml2-xpath.html#xmlXPathObject)*[xmlXPathObjectPtr](#xmlXPathObjectPtr);
typedef struct _xmlXPathAxis[xmlXPathAxis](#xmlXPathAxis);
typedef[xmlXPathAxis](libxml2-xpath.html#xmlXPathAxis)*[xmlXPathAxisPtr](#xmlXPathAxisPtr);
typedef struct _xmlXPathParserContext[xmlXPathParserContext](#xmlXPathParserContext);
int[xmlXPathCastNodeSetToBoolean](#xmlXPathCastNodeSetToBoolean)([xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)ns);
typedef[xmlXPathFunction](libxml2-xpath.html#xmlXPathFunction)[xmlXPathFuncLookupFunc](#xmlXPathFuncLookupFunc)(void * ctxt,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* name,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* ns_uri);[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathNodeEval](#xmlXPathNodeEval)([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* str,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctx);[xmlChar](libxml2-xmlstring.html#xmlChar)*[xmlXPathCastNodeToString](#xmlXPathCastNodeToString)([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node);
int[xmlXPathIsNaN](#xmlXPathIsNaN)(double val);
int[xmlXPathContextSetCache](#xmlXPathContextSetCache)([xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt,
int active,
int value,
int options);[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathConvertString](#xmlXPathConvertString)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val);
int[xmlXPathCompiledEvalToBoolean](#xmlXPathCompiledEvalToBoolean)([xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)comp,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt);
int[xmlXPathIsInf](#xmlXPathIsInf)(double val);
long[xmlXPathOrderDocElems](#xmlXPathOrderDocElems)([xmlDocPtr](libxml2-tree.html#xmlDocPtr)doc);[xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)[xmlXPathNodeSetCreate](#xmlXPathNodeSetCreate)([xmlNodePtr](libxml2-tree.html#xmlNodePtr)val);
double[xmlXPathCastBooleanToNumber](#xmlXPathCastBooleanToNumber)(int val);
double[xmlXPathCastNodeToNumber](#xmlXPathCastNodeToNumber)([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node);
double[xmlXPathCastStringToNumber](#xmlXPathCastStringToNumber)(const[xmlChar](libxml2-xmlstring.html#xmlChar)* val);
typedef[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathAxisFunc](#xmlXPathAxisFunc)([xmlXPathParserContextPtr](libxml2-xpath.html#xmlXPathParserContextPtr)ctxt,
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)cur);
double[xmlXPathCastToNumber](#xmlXPathCastToNumber)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val);
int[xmlXPathCastStringToBoolean](#xmlXPathCastStringToBoolean)(const[xmlChar](libxml2-xmlstring.html#xmlChar)* val);[xmlChar](libxml2-xmlstring.html#xmlChar)*[xmlXPathCastNumberToString](#xmlXPathCastNumberToString)(double val);
typedef[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathVariableLookupFunc](#xmlXPathVariableLookupFunc)(void * ctxt,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* name,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* ns_uri);
void[xmlXPathFreeObject](#xmlXPathFreeObject)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)obj);
int[xmlXPathEvalPredicate](#xmlXPathEvalPredicate)([xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt,
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)res);
void[xmlXPathFreeContext](#xmlXPathFreeContext)([xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt);[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathObjectCopy](#xmlXPathObjectCopy)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val);
void[xmlXPathFreeNodeSetList](#xmlXPathFreeNodeSetList)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)obj);[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathEval](#xmlXPathEval)(const[xmlChar](libxml2-xmlstring.html#xmlChar)* str,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctx);[xmlChar](libxml2-xmlstring.html#xmlChar)*[xmlXPathCastNodeSetToString](#xmlXPathCastNodeSetToString)([xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)ns);[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathCompiledEval](#xmlXPathCompiledEval)([xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)comp,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctx);[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathEvalExpression](#xmlXPathEvalExpression)(const[xmlChar](libxml2-xmlstring.html#xmlChar)* str,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt);
void[xmlXPathInit](#xmlXPathInit)(void);[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathConvertBoolean](#xmlXPathConvertBoolean)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val);
typedef int[xmlXPathConvertFunc](#xmlXPathConvertFunc)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)obj,
int type);
typedef void[xmlXPathFunction](#xmlXPathFunction)([xmlXPathParserContextPtr](libxml2-xpath.html#xmlXPathParserContextPtr)ctxt,
int nargs);
int[xmlXPathCmpNodes](#xmlXPathCmpNodes)([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node1,
[xmlNodePtr](libxml2-tree.html#xmlNodePtr)node2);[xmlChar](libxml2-xmlstring.html#xmlChar)*[xmlXPathCastToString](#xmlXPathCastToString)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val);[xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)[xmlXPathCtxtCompile](#xmlXPathCtxtCompile)([xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* str);
typedef void[xmlXPathEvalFunc](#xmlXPathEvalFunc)([xmlXPathParserContextPtr](libxml2-xpath.html#xmlXPathParserContextPtr)ctxt,
int nargs);[xmlChar](libxml2-xmlstring.html#xmlChar)*[xmlXPathCastBooleanToString](#xmlXPathCastBooleanToString)(int val);
int[xmlXPathSetContextNode](#xmlXPathSetContextNode)([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctx);
int[xmlXPathCastNumberToBoolean](#xmlXPathCastNumberToBoolean)(double val);
void[xmlXPathFreeNodeSet](#xmlXPathFreeNodeSet)([xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)obj);
void[xmlXPathFreeCompExpr](#xmlXPathFreeCompExpr)([xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)comp);[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)[xmlXPathNewContext](#xmlXPathNewContext)([xmlDocPtr](libxml2-tree.html#xmlDocPtr)doc);[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)[xmlXPathConvertNumber](#xmlXPathConvertNumber)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val);[xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)[xmlXPathCompile](#xmlXPathCompile)(const[xmlChar](libxml2-xmlstring.html#xmlChar)* str);
double[xmlXPathCastNodeSetToNumber](#xmlXPathCastNodeSetToNumber)([xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)ns);
int[xmlXPathCastToBoolean](#xmlXPathCastToBoolean)([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val);
#define[XML\_XPATH\_CHECKNS](#XML_XPATH_CHECKNS);
check namespaces at compilation
#define[XML\_XPATH\_NOVAR](#XML_XPATH_NOVAR);
forbid variables in expression
#define[xmlXPathNodeSetGetLength](#xmlXPathNodeSetGetLength)(ns);
Implement a functionality similar to the DOM NodeList.length. Returns the number of nodes in the node-set.
| ns: | a node-set |
#define[xmlXPathNodeSetIsEmpty](#xmlXPathNodeSetIsEmpty)(ns);
Checks whether @ns is empty or not. Returns %TRUE if @ns is an empty node-set.
| ns: | a node-set |
#define[xmlXPathNodeSetItem](#xmlXPathNodeSetItem)(ns, index);
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)
| ns: | a node-set | | index: | index of a node in the set |
struct _xmlNodeSet {
int nodeNr : number of nodes in the set
int nodeMax : size of the array as allocated[xmlNodePtr](libxml2-tree.html#xmlNodePtr)* nodeTab : array of nodes in no particular order @@ with_ns to check wether name
} xmlNodeSet;
[xmlNodeSet](libxml2-xpath.html#xmlNodeSet)* xmlNodeSetPtr;
struct _xmlXPathAxis {
const[xmlChar](libxml2-xmlstring.html#xmlChar)* name : the axis name[xmlXPathAxisFunc](libxml2-xpath.html#xmlXPathAxisFunc)func : the search function
} xmlXPathAxis;
[xmlXPathAxis](libxml2-xpath.html#xmlXPathAxis)* xmlXPathAxisPtr;
struct _xmlXPathCompExpr {
The content of this structure is not made public by the API.
} xmlXPathCompExpr;
[xmlXPathCompExpr](libxml2-xpath.html#xmlXPathCompExpr)* xmlXPathCompExprPtr;
struct _xmlXPathContext {[xmlDocPtr](libxml2-tree.html#xmlDocPtr)doc : The current document[xmlNodePtr](libxml2-tree.html#xmlNodePtr)node : The current node
int nb_variables_unused : unused (hash table)
int max_variables_unused : unused (hash table)[xmlHashTablePtr](libxml2-hash.html#xmlHashTablePtr)varHash : Hash table of defined variables
int nb_types : number of defined types
int max_types : max number of types[xmlXPathTypePtr](libxml2-xpath.html#xmlXPathTypePtr)types : Array of defined types
int nb_funcs_unused : unused (hash table)
int max_funcs_unused : unused (hash table)[xmlHashTablePtr](libxml2-hash.html#xmlHashTablePtr)funcHash : Hash table of defined funcs
int nb_axis : number of defined axis
int max_axis : max number of axis[xmlXPathAxisPtr](libxml2-xpath.html#xmlXPathAxisPtr)axis : Array of defined axis the namespace nodes of the context node[xmlNsPtr](libxml2-tree.html#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 XPointer
int xptr : is this an XPointer context?[xmlNodePtr](libxml2-tree.html#xmlNodePtr)here : for here()[xmlNodePtr](libxml2-tree.html#xmlNodePtr)origin : for origin() the set of namespace declarations in scope for the expre[xmlHashTablePtr](libxml2-hash.html#xmlHashTablePtr)nsHash : The namespaces hash table[xmlXPathVariableLookupFunc](libxml2-xpath.html#xmlXPathVariableLookupFunc)varLookupFunc : variable lookup func
void * varLookupData : variable lookup data Possibility to link in an extra item
void * extra : needed for XSLT The function name and URI when calling a function
const[xmlChar](libxml2-xmlstring.html#xmlChar)* function
const[xmlChar](libxml2-xmlstring.html#xmlChar)* functionURI : function lookup function and data[xmlXPathFuncLookupFunc](libxml2-xpath.html#xmlXPathFuncLookupFunc)funcLookupFunc : function lookup func
void * funcLookupData : function lookup data temporary namespace lists kept for walking the n[xmlNsPtr](libxml2-tree.html#xmlNsPtr)* tmpNsList : Array of namespaces
int tmpNsNr : number of namespaces in scope error reporting mechanism
void * userData : user specific data block[xmlStructuredErrorFunc](libxml2-xmlerror.html#xmlStructuredErrorFunc)error : the callback in case of errors[xmlError](libxml2-xmlerror.html#xmlError)lastError : the last error[xmlNodePtr](libxml2-tree.html#xmlNodePtr)debugNode : the source node XSLT dictionary[xmlDictPtr](libxml2-dict.html#xmlDictPtr)dict : dictionary if any
int flags : flags to control compilation Cache for reusal of XPath objects
void * cache
} xmlXPathContext;
[xmlXPathContext](libxml2-xpath.html#xmlXPathContext)* xmlXPathContextPtr;
enum[xmlXPathError](#xmlXPathError){XPATH\_EXPRESSION\_OK= 0XPATH\_NUMBER\_ERROR= 1XPATH\_UNFINISHED\_LITERAL\_ERROR= 2XPATH\_START\_LITERAL\_ERROR= 3XPATH\_VARIABLE\_REF\_ERROR= 4XPATH\_UNDEF\_VARIABLE\_ERROR= 5XPATH\_INVALID\_PREDICATE\_ERROR= 6XPATH\_EXPR\_ERROR= 7XPATH\_UNCLOSED\_ERROR= 8XPATH\_UNKNOWN\_FUNC\_ERROR= 9XPATH\_INVALID\_OPERAND= 10XPATH\_INVALID\_TYPE= 11XPATH\_INVALID\_ARITY= 12XPATH\_INVALID\_CTXT\_SIZE= 13XPATH\_INVALID\_CTXT\_POSITION= 14XPATH\_MEMORY\_ERROR= 15XPTR\_SYNTAX\_ERROR= 16XPTR\_RESOURCE\_ERROR= 17XPTR\_SUB\_RESOURCE\_ERROR= 18XPATH\_UNDEF\_PREFIX\_ERROR= 19XPATH\_ENCODING\_ERROR= 20XPATH\_INVALID\_CHAR\_ERROR= 21XPATH\_INVALID\_CTXT= 22XPATH\_STACK\_ERROR= 23XPATH\_FORBID\_VARIABLE\_ERROR= 24
};
[xmlXPathFunct](libxml2-xpath.html#xmlXPathFunct)* xmlXPathFuncPtr;
struct _xmlXPathFunct {
const[xmlChar](libxml2-xmlstring.html#xmlChar)* name : the function name[xmlXPathEvalFunc](libxml2-xpath.html#xmlXPathEvalFunc)func : the evaluation function
} xmlXPathFunct;
struct _xmlXPathObject {[xmlXPathObjectType](libxml2-xpath.html#xmlXPathObjectType)type[xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)nodesetval
int boolval
double floatval[xmlChar](libxml2-xmlstring.html#xmlChar)* stringval
void * user
int index
void * user2
int index2
} xmlXPathObject;
[xmlXPathObject](libxml2-xpath.html#xmlXPathObject)* xmlXPathObjectPtr;
enum[xmlXPathObjectType](#xmlXPathObjectType){XPATH\_UNDEFINED= 0XPATH\_NODESET= 1XPATH\_BOOLEAN= 2XPATH\_NUMBER= 3XPATH\_STRING= 4XPATH\_POINT= 5XPATH\_RANGE= 6XPATH\_LOCATIONSET= 7XPATH\_USERS= 8XPATH\_XSLT\_TREE= 9 /* An XSLT value tree, non modifiable */
};
struct _xmlXPathParserContext {
const[xmlChar](libxml2-xmlstring.html#xmlChar)* cur : the current char being parsed
const[xmlChar](libxml2-xmlstring.html#xmlChar)* base : the full expression
int error : error code[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)context : the evaluation context[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)value : the current value
int valueNr : number of values stacked
int valueMax : max number of values stacked[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)* valueTab : stack of values[xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)comp : the precompiled expression
int xptr : it this an XPointer expression[xmlNodePtr](libxml2-tree.html#xmlNodePtr)ancestor : used for walking preceding axis
int valueFrame : used to limit Pop on the stack
} xmlXPathParserContext;
[xmlXPathParserContext](libxml2-xpath.html#xmlXPathParserContext)* xmlXPathParserContextPtr;
struct _xmlXPathType {
const[xmlChar](libxml2-xmlstring.html#xmlChar)* name : the type name[xmlXPathConvertFunc](libxml2-xpath.html#xmlXPathConvertFunc)func : the conversion function
} xmlXPathType;
[xmlXPathType](libxml2-xpath.html#xmlXPathType)* xmlXPathTypePtr;
struct _xmlXPathVariable {
const[xmlChar](libxml2-xmlstring.html#xmlChar)* name : the variable name[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)value : the value
} xmlXPathVariable;
[xmlXPathVariable](libxml2-xpath.html#xmlXPathVariable)* xmlXPathVariablePtr;
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathAxisFunc ([xmlXPathParserContextPtr](libxml2-xpath.html#xmlXPathParserContextPtr)ctxt,
[xmlXPathObjectPtr](libxml2-xpath.html#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.
| ctxt: | the XPath interpreter context | | cur: | the previous node being explored on that axis | | Returns: | the next node in that axis or NULL if at the end of the axis. |
int xmlXPathConvertFunc ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)obj,
int type)
A conversion function is associated to a type and used to cast the new type to primitive values.
| obj: | an XPath object | | type: | the number of the target type | | Returns: | -1 in case of error, 0 otherwise |
void xmlXPathEvalFunc ([xmlXPathParserContextPtr](libxml2-xpath.html#xmlXPathParserContextPtr)ctxt,
int nargs)
An XPath evaluation function, the parameters are on the XPath context stack.
| ctxt: | an XPath parser context | | nargs: | the number of arguments passed to the function |
[xmlXPathFunction](libxml2-xpath.html#xmlXPathFunction)xmlXPathFuncLookupFunc (void * ctxt,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* name,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* ns_uri)
Prototype for callbacks used to plug function lookup in the XPath engine.
| ctxt: | an XPath context | | name: | name of the function | | ns_uri: | the namespace name hosting this function | | Returns: | the XPath function or NULL if not found. |
void xmlXPathFunction ([xmlXPathParserContextPtr](libxml2-xpath.html#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.
| ctxt: | the XPath interprestation context | | nargs: | the number of arguments |
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathVariableLookupFunc (void * ctxt,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* name,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* ns_uri)
Prototype for callbacks used to plug variable lookup in the XPath engine.
| ctxt: | an XPath context | | name: | name of the variable | | ns_uri: | the namespace name hosting this variable | | Returns: | the XPath object value or NULL if not found. |
double xmlXPathNAN;
double xmlXPathNINF;
double xmlXPathPINF;
double xmlXPathCastBooleanToNumber (int val)
Converts a boolean to its number value
| val: | a boolean | | Returns: | the number value |
[xmlChar](libxml2-xmlstring.html#xmlChar)* xmlXPathCastBooleanToString (int val)
Converts a boolean to its string value.
| val: | a boolean | | Returns: | a newly allocated string. |
int xmlXPathCastNodeSetToBoolean ([xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)ns)
Converts a node-set to its boolean value
| ns: | a node-set | | Returns: | the boolean value |
double xmlXPathCastNodeSetToNumber ([xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)ns)
Converts a node-set to its number value
| ns: | a node-set | | Returns: | the number value |
[xmlChar](libxml2-xmlstring.html#xmlChar)* xmlXPathCastNodeSetToString ([xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)ns)
Converts a node-set to its string value.
| ns: | a node-set | | Returns: | a newly allocated string. |
double xmlXPathCastNodeToNumber ([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node)
Converts a node to its number value
| node: | a node | | Returns: | the number value |
[xmlChar](libxml2-xmlstring.html#xmlChar)* xmlXPathCastNodeToString ([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node)
Converts a node to its string value.
| node: | a node | | Returns: | a newly allocated string. |
int xmlXPathCastNumberToBoolean (double val)
Converts a number to its boolean value
| val: | a number | | Returns: | the boolean value |
[xmlChar](libxml2-xmlstring.html#xmlChar)* xmlXPathCastNumberToString (double val)
Converts a number to its string value.
| val: | a number | | Returns: | a newly allocated string. |
int xmlXPathCastStringToBoolean (const[xmlChar](libxml2-xmlstring.html#xmlChar)* val)
Converts a string to its boolean value
| val: | a string | | Returns: | the boolean value |
double xmlXPathCastStringToNumber (const[xmlChar](libxml2-xmlstring.html#xmlChar)* val)
Converts a string to its number value
| val: | a string | | Returns: | the number value |
int xmlXPathCastToBoolean ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val)
Converts an XPath object to its boolean value
| val: | an XPath object | | Returns: | the boolean value |
double xmlXPathCastToNumber ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val)
Converts an XPath object to its number value
| val: | an XPath object | | Returns: | the number value |
[xmlChar](libxml2-xmlstring.html#xmlChar)* xmlXPathCastToString ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val)
Converts an existing object to its string() equivalent
| val: | an XPath object | | Returns: | the allocated string value of the object, NULL in case of error. It's up to the caller to free the string memory with xmlFree(). |
int xmlXPathCmpNodes ([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node1,
[xmlNodePtr](libxml2-tree.html#xmlNodePtr)node2)
Compare two nodes w.r.t document order
| node1: | the first node | | node2: | the second node | | Returns: | -2 in case of error 1 if first point < second point, 0 if it's the same node, -1 otherwise |
[xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)xmlXPathCompile (const[xmlChar](libxml2-xmlstring.html#xmlChar)* str)
Compile an XPath expression
| str: | the XPath expression | | Returns: | the xmlXPathCompExprPtr resulting from the compilation or NULL. the caller has to free the object. |
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathCompiledEval ([xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)comp,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctx)
Evaluate the Precompiled XPath expression in the given context.
| comp: | the compiled XPath expression | | ctx: | the XPath context | | Returns: | the xmlXPathObjectPtr resulting from the evaluation or NULL. the caller has to free the object. |
int xmlXPathCompiledEvalToBoolean ([xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)comp,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt)
Applies the XPath boolean() function on the result of the given compiled expression.
| comp: | the compiled XPath expression | | ctxt: | the XPath context | | Returns: | 1 if the expression evaluated to true, 0 if to false and -1 in API and internal errors. |
int xmlXPathContextSetCache ([xmlXPathContextPtr](libxml2-xpath.html#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.
| ctxt: | the XPath context | | active: | enables/disables (creates/frees) the cache | | value: | a value with semantics dependant on @options | | options: | options (currently only the value 0 is used) | | Returns: | 0 if the setting succeeded, and -1 on API or internal errors. |
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathConvertBoolean ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val)
Converts an existing object to its boolean() equivalent
| val: | an XPath object | | Returns: | the new object, the old one is freed (or the operation is done directly on @val) |
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathConvertNumber ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val)
Converts an existing object to its number() equivalent
| val: | an XPath object | | Returns: | the new object, the old one is freed (or the operation is done directly on @val) |
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathConvertString ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val)
Converts an existing object to its string() equivalent
| val: | an XPath object | | Returns: | the new object, the old one is freed (or the operation is done directly on @val) |
[xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)xmlXPathCtxtCompile ([xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* str)
Compile an XPath expression
| ctxt: | an XPath context | | str: | the XPath expression | | Returns: | the xmlXPathCompExprPtr resulting from the compilation or NULL. the caller has to free the object. |
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathEval (const[xmlChar](libxml2-xmlstring.html#xmlChar)* str,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctx)
Evaluate the XPath Location Path in the given context.
| str: | the XPath expression | | ctx: | the XPath context | | Returns: | the xmlXPathObjectPtr resulting from the evaluation or NULL. the caller has to free the object. |
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathEvalExpression (const[xmlChar](libxml2-xmlstring.html#xmlChar)* str,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt)
Evaluate the XPath expression in the given context.
| str: | the XPath expression | | ctxt: | the XPath context | | Returns: | the xmlXPathObjectPtr resulting from the evaluation or NULL. the caller has to free the object. |
int xmlXPathEvalPredicate ([xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt,
[xmlXPathObjectPtr](libxml2-xpath.html#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.
| ctxt: | the XPath context | | res: | the Predicate Expression evaluation result | | Returns: | 1 if predicate is true, 0 otherwise |
void xmlXPathFreeCompExpr ([xmlXPathCompExprPtr](libxml2-xpath.html#xmlXPathCompExprPtr)comp)
Free up the memory allocated by @comp
| comp: | an XPATH comp |
void xmlXPathFreeContext ([xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctxt)
Free up an xmlXPathContext
| ctxt: | the context to free |
void xmlXPathFreeNodeSet ([xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)obj)
Free the NodeSet compound (not the actual nodes !).
| obj: | the xmlNodeSetPtr to free |
void xmlXPathFreeNodeSetList ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)obj)
Free up the xmlXPathObjectPtr @obj but don't deallocate the objects in the list contrary to xmlXPathFreeObject().
| obj: | an existing NodeSetList object |
void xmlXPathFreeObject ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)obj)
Free up an xmlXPathObjectPtr object.
| obj: | the object to free |
void xmlXPathInit (void)
Initialize the XPath environment
int xmlXPathIsInf (double val)
Provides a portable isinf() function to detect whether a double is a +Infinite or -Infinite. Based on trio code http://sourceforge.net/projects/ctrio/
| val: | a double value | | Returns: | 1 vi the value is +Infinite, -1 if -Infinite, 0 otherwise |
int xmlXPathIsNaN (double val)
Provides a portable isnan() function to detect whether a double is a NotaNumber. Based on trio code http://sourceforge.net/projects/ctrio/
| val: | a double value | | Returns: | 1 if the value is a NaN, 0 otherwise |
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)xmlXPathNewContext ([xmlDocPtr](libxml2-tree.html#xmlDocPtr)doc)
Create a new xmlXPathContext
| doc: | the XML document | | Returns: | the xmlXPathContext just allocated. The caller will need to free it. |
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathNodeEval ([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node,
const[xmlChar](libxml2-xmlstring.html#xmlChar)* str,
[xmlXPathContextPtr](libxml2-xpath.html#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.
| node: | the node to to use as the context node | | str: | the XPath expression | | ctx: | the XPath context | | Returns: | the xmlXPathObjectPtr resulting from the evaluation or NULL. the caller has to free the object. |
[xmlNodeSetPtr](libxml2-xpath.html#xmlNodeSetPtr)xmlXPathNodeSetCreate ([xmlNodePtr](libxml2-tree.html#xmlNodePtr)val)
Create a new xmlNodeSetPtr of type double and of value @val
| val: | an initial xmlNodePtr, or NULL | | Returns: | the newly created object. |
[xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)xmlXPathObjectCopy ([xmlXPathObjectPtr](libxml2-xpath.html#xmlXPathObjectPtr)val)
allocate a new copy of a given object
| val: | the original object | | Returns: | the newly created object. |
long xmlXPathOrderDocElems ([xmlDocPtr](libxml2-tree.html#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.
| doc: | an input document | | Returns: | the number of elements found in the document or -1 in case of error. |
int xmlXPathSetContextNode ([xmlNodePtr](libxml2-tree.html#xmlNodePtr)node,
[xmlXPathContextPtr](libxml2-xpath.html#xmlXPathContextPtr)ctx)
Sets 'node' as the context node. The node must be in the same document as that associated with the context.
| node: | the node to to use as the context node | | ctx: | the XPath context | | Returns: | -1 in case of error or 0 if successful |