Edit File: xpath.h
/* * Summary: XML Path Language implementation * Description: 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 * http://www.w3.org/TR/xpath * * Implements * W3C Recommendation 16 November 1999 * http://www.w3.org/TR/1999/REC-xpath-19991116 * * Copy: See Copyright for the status of this software. * * Author: Daniel Veillard */ #ifndef __XML_XPATH_H__ #define __XML_XPATH_H__ #include <libxml/xmlversion.h> #ifdef LIBXML_XPATH_ENABLED #include <libxml/xmlerror.h> #include <libxml/tree.h> #include <libxml/hash.h> #endif /* LIBXML_XPATH_ENABLED */ #if defined(LIBXML_XPATH_ENABLED) || defined(LIBXML_SCHEMAS_ENABLED) #ifdef __cplusplus extern "C" { #endif #endif /* LIBXML_XPATH_ENABLED or LIBXML_SCHEMAS_ENABLED */ #ifdef LIBXML_XPATH_ENABLED typedef struct _xmlXPathContext xmlXPathContext; typedef xmlXPathContext *xmlXPathContextPtr; typedef struct _xmlXPathParserContext xmlXPathParserContext; typedef xmlXPathParserContext *xmlXPathParserContextPtr; /** * The set of XPath error codes. */ typedef enum { XPATH_EXPRESSION_OK = 0, XPATH_NUMBER_ERROR, XPATH_UNFINISHED_LITERAL_ERROR, XPATH_START_LITERAL_ERROR, XPATH_VARIABLE_REF_ERROR, XPATH_UNDEF_VARIABLE_ERROR, XPATH_INVALID_PREDICATE_ERROR, XPATH_EXPR_ERROR, XPATH_UNCLOSED_ERROR, XPATH_UNKNOWN_FUNC_ERROR, XPATH_INVALID_OPERAND, XPATH_INVALID_TYPE, XPATH_INVALID_ARITY, XPATH_INVALID_CTXT_SIZE, XPATH_INVALID_CTXT_POSITION, XPATH_MEMORY_ERROR, XPTR_SYNTAX_ERROR, XPTR_RESOURCE_ERROR, XPTR_SUB_RESOURCE_ERROR, XPATH_UNDEF_PREFIX_ERROR, XPATH_ENCODING_ERROR, XPATH_INVALID_CHAR_ERROR, XPATH_INVALID_CTXT, XPATH_STACK_ERROR, XPATH_FORBID_VARIABLE_ERROR, XPATH_OP_LIMIT_EXCEEDED, XPATH_RECURSION_LIMIT_EXCEEDED } xmlXPathError; /* * A node-set (an unordered collection of nodes without duplicates). */ typedef struct _xmlNodeSet xmlNodeSet; typedef xmlNodeSet *xmlNodeSetPtr; 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 */ /* @@ with_ns to check whether namespace nodes should be looked at @@ */ }; /* * An expression is evaluated to yield an object, which * has one of the following four basic types: * - node-set * - boolean * - number * - string * * @@ XPointer will add more types ! */ typedef enum { XPATH_UNDEFINED = 0, XPATH_NODESET = 1, XPATH_BOOLEAN = 2, XPATH_NUMBER = 3, XPATH_STRING = 4, #ifdef LIBXML_XPTR_LOCS_ENABLED XPATH_POINT = 5, XPATH_RANGE = 6, XPATH_LOCATIONSET = 7, #endif XPATH_USERS = 8, XPATH_XSLT_TREE = 9 /* An XSLT value tree, non modifiable */ } xmlXPathObjectType; #ifndef LIBXML_XPTR_LOCS_ENABLED /** DOC_DISABLE */ #define XPATH_POINT 5 #define XPATH_RANGE 6 #define XPATH_LOCATIONSET 7 /** DOC_ENABLE */ #endif typedef struct _xmlXPathObject xmlXPathObject; typedef xmlXPathObject *xmlXPathObjectPtr; struct _xmlXPathObject { xmlXPathObjectType type; xmlNodeSetPtr nodesetval; int boolval; double floatval; xmlChar *stringval; void *user; int index; void *user2; int index2; }; /** * xmlXPathConvertFunc: * @obj: an XPath object * @type: the number of the target type * * A conversion function is associated to a type and used to cast * the new type to primitive values. * * Returns -1 in case of error, 0 otherwise */ typedef int (*xmlXPathConvertFunc) (xmlXPathObjectPtr obj, int type); /* * Extra type: a name and a conversion function. */ typedef struct _xmlXPathType xmlXPathType; typedef xmlXPathType *xmlXPathTypePtr; struct _xmlXPathType { const xmlChar *name; /* the type name */ xmlXPathConvertFunc func; /* the conversion function */ }; /* * Extra variable: a name and a value. */ typedef struct _xmlXPathVariable xmlXPathVariable; typedef xmlXPathVariable *xmlXPathVariablePtr; struct _xmlXPathVariable { const xmlChar *name; /* the variable name */ xmlXPathObjectPtr value; /* the value */ }; /** * xmlXPathEvalFunc: * @ctxt: an XPath parser context * @nargs: the number of arguments passed to the function * * An XPath evaluation function, the parameters are on the XPath context stack. */ typedef void (*xmlXPathEvalFunc)(xmlXPathParserContextPtr ctxt, int nargs); /* * Extra function: a name and a evaluation function. */ typedef struct _xmlXPathFunct xmlXPathFunct; typedef xmlXPathFunct *xmlXPathFuncPtr; struct _xmlXPathFunct { const xmlChar *name; /* the function name */ xmlXPathEvalFunc func; /* the evaluation function */ }; /** * xmlXPathAxisFunc: * @ctxt: the XPath interpreter context * @cur: the previous node being explored on that axis * * 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. * * Returns the next node in that axis or NULL if at the end of the axis. */ typedef xmlXPathObjectPtr (*xmlXPathAxisFunc) (xmlXPathParserContextPtr ctxt, xmlXPathObjectPtr cur); /* * Extra axis: a name and an axis function. */ typedef struct _xmlXPathAxis xmlXPathAxis; typedef xmlXPathAxis *xmlXPathAxisPtr; struct _xmlXPathAxis { const xmlChar *name; /* the axis name */ xmlXPathAxisFunc func; /* the search function */ }; /** * xmlXPathFunction: * @ctxt: the XPath interprestation context * @nargs: the number of arguments * * An XPath function. * The arguments (if any) are popped out from the context stack * and the result is pushed on the stack. */ typedef void (*xmlXPathFunction) (xmlXPathParserContextPtr ctxt, int nargs); /* * Function and Variable Lookup. */ /** * xmlXPathVariableLookupFunc: * @ctxt: an XPath context * @name: name of the variable * @ns_uri: the namespace name hosting this variable * * Prototype for callbacks used to plug variable lookup in the XPath * engine. * * Returns the XPath object value or NULL if not found. */ typedef xmlXPathObjectPtr (*xmlXPathVariableLookupFunc) (void *ctxt, const xmlChar *name, const xmlChar *ns_uri); /** * xmlXPathFuncLookupFunc: * @ctxt: an XPath context * @name: name of the function * @ns_uri: the namespace name hosting this function * * Prototype for callbacks used to plug function lookup in the XPath * engine. * * Returns the XPath function or NULL if not found. */ typedef xmlXPathFunction (*xmlXPathFuncLookupFunc) (void *ctxt, const xmlChar *name, const xmlChar *ns_uri); /** * xmlXPathFlags: * Flags for XPath engine compilation and runtime */ /** * XML_XPATH_CHECKNS: * * check namespaces at compilation */ #define XML_XPATH_CHECKNS (1<<0) /** * XML_XPATH_NOVAR: * * forbid variables in expression */ #define XML_XPATH_NOVAR (1<<1) /** * xmlXPathContext: * * Expression evaluation occurs with respect to a context. * he context consists of: * - a node (the context node) * - a node list (the context node list) * - a set of variable bindings * - a function library * - the set of namespace declarations in scope for the expression * Following the switch to hash tables, this need to be trimmed up at * the next binary incompatible release. * The node may be modified when the context is passed to libxml2 * for an XPath evaluation so you may need to initialize it again * before the next call. */ 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 nodes of the context node */ 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 here; /* for here() */ xmlNodePtr origin; /* for origin() */ /* the set of namespace declarations in scope for the expression */ xmlHashTablePtr nsHash; /* The namespaces hash table */ 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 *function; const xmlChar *functionURI; /* function lookup function and data */ xmlXPathFuncLookupFunc funcLookupFunc;/* function lookup func */ void *funcLookupData; /* function lookup data */ /* temporary namespace lists kept for walking the namespace axis */ xmlNsPtr *tmpNsList; /* Array of namespaces */ int tmpNsNr; /* number of namespaces in scope */ /* error reporting mechanism */ 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 reusal of XPath objects */ void *cache; /* Resource limits */ unsigned long opLimit; unsigned long opCount; int depth; }; /* * The structure of a compiled expression form is not public. */ typedef struct _xmlXPathCompExpr xmlXPathCompExpr; typedef xmlXPathCompExpr *xmlXPathCompExprPtr; /** * xmlXPathParserContext: * * An XPath parser context. It contains pure parsing information, * an xmlXPathContext, and the stack of objects. */ 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; /* always zero for compatibility */ }; /************************************************************************ * * * Public API * * * ************************************************************************/ /** * Objects and Nodesets handling */ XMLPUBVAR double xmlXPathNAN; XMLPUBVAR double xmlXPathPINF; XMLPUBVAR double xmlXPathNINF; /* These macros may later turn into functions */ /** * xmlXPathNodeSetGetLength: * @ns: a node-set * * Implement a functionality similar to the DOM NodeList.length. * * Returns the number of nodes in the node-set. */ #define xmlXPathNodeSetGetLength(ns) ((ns) ? (ns)->nodeNr : 0) /** * xmlXPathNodeSetItem: * @ns: a node-set * @index: index of a node in the set * * 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) */ #define xmlXPathNodeSetItem(ns, index) \ ((((ns) != NULL) && \ ((index) >= 0) && ((index) < (ns)->nodeNr)) ? \ (ns)->nodeTab[(index)] \ : NULL) /** * xmlXPathNodeSetIsEmpty: * @ns: a node-set * * Checks whether @ns is empty or not. * * Returns %TRUE if @ns is an empty node-set. */ #define xmlXPathNodeSetIsEmpty(ns) \ (((ns) == NULL) || ((ns)->nodeNr == 0) || ((ns)->nodeTab == NULL)) XMLPUBFUN void xmlXPathFreeObject (xmlXPathObjectPtr obj); XMLPUBFUN xmlNodeSetPtr xmlXPathNodeSetCreate (xmlNodePtr val); XMLPUBFUN void xmlXPathFreeNodeSetList (xmlXPathObjectPtr obj); XMLPUBFUN void xmlXPathFreeNodeSet (xmlNodeSetPtr obj); XMLPUBFUN xmlXPathObjectPtr xmlXPathObjectCopy (xmlXPathObjectPtr val); XMLPUBFUN int xmlXPathCmpNodes (xmlNodePtr node1, xmlNodePtr node2); /** * Conversion functions to basic types. */ XMLPUBFUN int xmlXPathCastNumberToBoolean (double val); XMLPUBFUN int xmlXPathCastStringToBoolean (const xmlChar * val); XMLPUBFUN int xmlXPathCastNodeSetToBoolean(xmlNodeSetPtr ns); XMLPUBFUN int xmlXPathCastToBoolean (xmlXPathObjectPtr val); XMLPUBFUN double xmlXPathCastBooleanToNumber (int val); XMLPUBFUN double xmlXPathCastStringToNumber (const xmlChar * val); XMLPUBFUN double xmlXPathCastNodeToNumber (xmlNodePtr node); XMLPUBFUN double xmlXPathCastNodeSetToNumber (xmlNodeSetPtr ns); XMLPUBFUN double xmlXPathCastToNumber (xmlXPathObjectPtr val); XMLPUBFUN xmlChar * xmlXPathCastBooleanToString (int val); XMLPUBFUN xmlChar * xmlXPathCastNumberToString (double val); XMLPUBFUN xmlChar * xmlXPathCastNodeToString (xmlNodePtr node); XMLPUBFUN xmlChar * xmlXPathCastNodeSetToString (xmlNodeSetPtr ns); XMLPUBFUN xmlChar * xmlXPathCastToString (xmlXPathObjectPtr val); XMLPUBFUN xmlXPathObjectPtr xmlXPathConvertBoolean (xmlXPathObjectPtr val); XMLPUBFUN xmlXPathObjectPtr xmlXPathConvertNumber (xmlXPathObjectPtr val); XMLPUBFUN xmlXPathObjectPtr xmlXPathConvertString (xmlXPathObjectPtr val); /** * Context handling. */ XMLPUBFUN xmlXPathContextPtr xmlXPathNewContext (xmlDocPtr doc); XMLPUBFUN void xmlXPathFreeContext (xmlXPathContextPtr ctxt); XMLPUBFUN void xmlXPathSetErrorHandler(xmlXPathContextPtr ctxt, xmlStructuredErrorFunc handler, void *context); XMLPUBFUN int xmlXPathContextSetCache(xmlXPathContextPtr ctxt, int active, int value, int options); /** * Evaluation functions. */ XMLPUBFUN long xmlXPathOrderDocElems (xmlDocPtr doc); XMLPUBFUN int xmlXPathSetContextNode (xmlNodePtr node, xmlXPathContextPtr ctx); XMLPUBFUN xmlXPathObjectPtr xmlXPathNodeEval (xmlNodePtr node, const xmlChar *str, xmlXPathContextPtr ctx); XMLPUBFUN xmlXPathObjectPtr xmlXPathEval (const xmlChar *str, xmlXPathContextPtr ctx); XMLPUBFUN xmlXPathObjectPtr xmlXPathEvalExpression (const xmlChar *str, xmlXPathContextPtr ctxt); XMLPUBFUN int xmlXPathEvalPredicate (xmlXPathContextPtr ctxt, xmlXPathObjectPtr res); /** * Separate compilation/evaluation entry points. */ XMLPUBFUN xmlXPathCompExprPtr xmlXPathCompile (const xmlChar *str); XMLPUBFUN xmlXPathCompExprPtr xmlXPathCtxtCompile (xmlXPathContextPtr ctxt, const xmlChar *str); XMLPUBFUN xmlXPathObjectPtr xmlXPathCompiledEval (xmlXPathCompExprPtr comp, xmlXPathContextPtr ctx); XMLPUBFUN int xmlXPathCompiledEvalToBoolean(xmlXPathCompExprPtr comp, xmlXPathContextPtr ctxt); XMLPUBFUN void xmlXPathFreeCompExpr (xmlXPathCompExprPtr comp); #endif /* LIBXML_XPATH_ENABLED */ #if defined(LIBXML_XPATH_ENABLED) || defined(LIBXML_SCHEMAS_ENABLED) XML_DEPRECATED XMLPUBFUN void xmlXPathInit (void); XMLPUBFUN int xmlXPathIsNaN (double val); XMLPUBFUN int xmlXPathIsInf (double val); #ifdef __cplusplus } #endif #endif /* LIBXML_XPATH_ENABLED or LIBXML_SCHEMAS_ENABLED*/ #endif /* ! __XML_XPATH_H__ */