← Back
Editing: xpath.h
/** * @file * * @brief 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 * http://www.w3.org/TR/xpath * * Implements * W3C Recommendation 16 November 1999 * http://www.w3.org/TR/1999/REC-xpath-19991116 * * @copyright 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> #ifdef __cplusplus extern "C" { #endif /** XPath context */ typedef struct _xmlXPathContext xmlXPathContext; typedef xmlXPathContext *xmlXPathContextPtr; /** XPath parser and evaluation context */ 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; /** XPath node set */ typedef struct _xmlNodeSet xmlNodeSet; typedef xmlNodeSet *xmlNodeSetPtr; /** * A node-set (an unordered collection of nodes without duplicates). */ struct _xmlNodeSet { /** number of nodes in the set */ int nodeNr; /** size of the array as allocated */ int nodeMax; /** array of nodes in no particular order */ xmlNode **nodeTab; }; /** * An expression is evaluated to yield an object, which * has one of the following four basic types: * * - node-set * - boolean * - number * - string */ typedef enum { XPATH_UNDEFINED = 0, XPATH_NODESET = 1, XPATH_BOOLEAN = 2, XPATH_NUMBER = 3, XPATH_STRING = 4, XPATH_USERS = 8, XPATH_XSLT_TREE = 9 /* An XSLT value tree, non modifiable */ } xmlXPathObjectType; /** @cond IGNORE */ #define XPATH_POINT 5 #define XPATH_RANGE 6 #define XPATH_LOCATIONSET 7 /** @endcond */ /** XPath object */ typedef struct _xmlXPathObject xmlXPathObject; typedef xmlXPathObject *xmlXPathObjectPtr; /** * An XPath object */ struct _xmlXPathObject { /** object type */ xmlXPathObjectType type; /** node set */ xmlNodeSet *nodesetval; /** boolean */ int boolval; /** number */ double floatval; /** string */ xmlChar *stringval; void *user; int index; void *user2; int index2; }; /** @cond ignore */ /* * unused */ typedef int (*xmlXPathConvertFunc) (xmlXPathObject *obj, int type); typedef struct _xmlXPathType xmlXPathType; typedef xmlXPathType *xmlXPathTypePtr; struct _xmlXPathType { const xmlChar *name; /* the type name */ xmlXPathConvertFunc func; /* the conversion function */ }; /* * unused */ typedef struct _xmlXPathVariable xmlXPathVariable; typedef xmlXPathVariable *xmlXPathVariablePtr; struct _xmlXPathVariable { const xmlChar *name; /* the variable name */ xmlXPathObject *value; /* the value */ }; /* * unused */ typedef void (*xmlXPathEvalFunc)(xmlXPathParserContext *ctxt, int nargs); typedef struct _xmlXPathFunct xmlXPathFunct; typedef xmlXPathFunct *xmlXPathFuncPtr; struct _xmlXPathFunct { const xmlChar *name; /* the function name */ xmlXPathEvalFunc func; /* the evaluation function */ }; /* * unused */ typedef xmlXPathObject *(*xmlXPathAxisFunc) (xmlXPathParserContext *ctxt, xmlXPathObject *cur); typedef struct _xmlXPathAxis xmlXPathAxis; typedef xmlXPathAxis *xmlXPathAxisPtr; struct _xmlXPathAxis { const xmlChar *name; /* the axis name */ xmlXPathAxisFunc func; /* the search function */ }; /** @endcond */ /** * An XPath function. * The arguments (if any) are popped out from the context stack * and the result is pushed on the stack. * * @param ctxt the XPath interprestation context * @param nargs the number of arguments */ typedef void (*xmlXPathFunction) (xmlXPathParserContext *ctxt, int nargs); /* * Function and Variable Lookup. */ /** * Prototype for callbacks used to plug variable lookup in the XPath * engine. * * @param ctxt an XPath context * @param name name of the variable * @param ns_uri the namespace name hosting this variable * @returns the XPath object value or NULL if not found. */ typedef xmlXPathObject *(*xmlXPathVariableLookupFunc) (void *ctxt, const xmlChar *name, const xmlChar *ns_uri); /** * Prototype for callbacks used to plug function lookup in the XPath * engine. * * @param ctxt an XPath context * @param name name of the function * @param ns_uri the namespace name hosting this function * @returns the XPath function or NULL if not found. */ typedef xmlXPathFunction (*xmlXPathFuncLookupFunc) (void *ctxt, const xmlChar *name, const xmlChar *ns_uri); /** * Flags for XPath engine compilation and runtime */ /** * check namespaces at compilation */ #define XML_XPATH_CHECKNS (1<<0) /** * forbid variables in expression */ #define XML_XPATH_NOVAR (1<<1) /** * 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 { /** The current document */ xmlDoc *doc; /** The current node */ xmlNode *node; /* unused (hash table) */ int nb_variables_unused; /* unused (hash table) */ int max_variables_unused; /* Hash table of defined variables */ xmlHashTable *varHash; /* number of defined types */ int nb_types; /* max number of types */ int max_types; /* Array of defined types */ xmlXPathType *types; /* unused (hash table) */ int nb_funcs_unused; /* unused (hash table) */ int max_funcs_unused; /* Hash table of defined funcs */ xmlHashTable *funcHash; /* number of defined axis */ int nb_axis; /* max number of axis */ int max_axis; /* Array of defined axis */ xmlXPathAxis *axis; /* Array of namespaces */ xmlNs **namespaces; /* number of namespace in scope */ int nsNr; /* function to free */ void *user; /** the context size */ int contextSize; /** the proximity position */ int proximityPosition; /* is this an XPointer context? */ int xptr; /* for here() */ xmlNode *here; /* for origin() */ xmlNode *origin; /* The namespaces hash table */ xmlHashTable *nsHash; /* variable lookup func */ xmlXPathVariableLookupFunc varLookupFunc; /* variable lookup data */ void *varLookupData; /* needed for XSLT */ void *extra; /* The function name when calling a function */ const xmlChar *function; /* The namespace URI when calling a function */ const xmlChar *functionURI; /* function lookup func */ xmlXPathFuncLookupFunc funcLookupFunc; /* function lookup data */ void *funcLookupData; /* Array of temp namespaces */ xmlNs **tmpNsList; /* number of namespaces in scope */ int tmpNsNr; /* user specific data block */ void *userData; /* the callback in case of errors */ xmlStructuredErrorFunc error; /* the last error */ xmlError lastError; /* the source node XSLT */ xmlNode *debugNode; /* dictionary if any */ xmlDict *dict; /** flags to control compilation */ int flags; /* Cache for reusal of XPath objects */ void *cache; /* Resource limits */ unsigned long opLimit; unsigned long opCount; int depth; }; /** Compiled XPath expression */ typedef struct _xmlXPathCompExpr xmlXPathCompExpr; typedef xmlXPathCompExpr *xmlXPathCompExprPtr; /** * An XPath parser context. It contains pure parsing information, * an xmlXPathContext, and the stack of objects. * * This struct is used for evaluation as well and misnamed. */ struct _xmlXPathParserContext { /* the current char being parsed */ const xmlChar *cur; /* the full expression */ const xmlChar *base; /** error code */ int error; /** the evaluation context */ xmlXPathContext *context; /** the current value */ xmlXPathObject *value; /* number of values stacked */ int valueNr; /* max number of values stacked */ int valueMax; /* stack of values */ xmlXPathObject **valueTab; /* the precompiled expression */ xmlXPathCompExpr *comp; /* it this an XPointer expression */ int xptr; /* used for walking preceding axis */ xmlNode *ancestor; /* always zero for compatibility */ int valueFrame; }; /************************************************************************ * * * Public API * * * ************************************************************************/ /** * Objects and Nodesets handling */ /** @cond ignore */ XML_DEPRECATED XMLPUBVAR double xmlXPathNAN; XML_DEPRECATED XMLPUBVAR double xmlXPathPINF; XML_DEPRECATED XMLPUBVAR double xmlXPathNINF; /* These macros may later turn into functions */ /** * Implement a functionality similar to the DOM NodeList.length. * * @param ns a node-set * @returns the number of nodes in the node-set. */ #define xmlXPathNodeSetGetLength(ns) ((ns) ? (ns)->nodeNr : 0) /** * Implements a functionality similar to the DOM NodeList.item(). * * @param ns a node-set * @param index index of a node in the set * @returns the xmlNode 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) /** * Checks whether `ns` is empty or not. * * @param ns a node-set * @returns %TRUE if `ns` is an empty node-set. */ #define xmlXPathNodeSetIsEmpty(ns) \ (((ns) == NULL) || ((ns)->nodeNr == 0) || ((ns)->nodeTab == NULL)) /** @endcond */ XMLPUBFUN void xmlXPathFreeObject (xmlXPathObject *obj); XMLPUBFUN xmlNodeSet * xmlXPathNodeSetCreate (xmlNode *val); XMLPUBFUN void xmlXPathFreeNodeSetList (xmlXPathObject *obj); XMLPUBFUN void xmlXPathFreeNodeSet (xmlNodeSet *obj); XMLPUBFUN xmlXPathObject * xmlXPathObjectCopy (xmlXPathObject *val); XMLPUBFUN int xmlXPathCmpNodes (xmlNode *node1, xmlNode *node2); /** * Conversion functions to basic types. */ XMLPUBFUN int xmlXPathCastNumberToBoolean (double val); XMLPUBFUN int xmlXPathCastStringToBoolean (const xmlChar * val); XMLPUBFUN int xmlXPathCastNodeSetToBoolean(xmlNodeSet *ns); XMLPUBFUN int xmlXPathCastToBoolean (xmlXPathObject *val); XMLPUBFUN double xmlXPathCastBooleanToNumber (int val); XMLPUBFUN double xmlXPathCastStringToNumber (const xmlChar * val); XMLPUBFUN double xmlXPathCastNodeToNumber (xmlNode *node); XMLPUBFUN double xmlXPathCastNodeSetToNumber (xmlNodeSet *ns); XMLPUBFUN double xmlXPathCastToNumber (xmlXPathObject *val); XMLPUBFUN xmlChar * xmlXPathCastBooleanToString (int val); XMLPUBFUN xmlChar * xmlXPathCastNumberToString (double val); XMLPUBFUN xmlChar * xmlXPathCastNodeToString (xmlNode *node); XMLPUBFUN xmlChar * xmlXPathCastNodeSetToString (xmlNodeSet *ns); XMLPUBFUN xmlChar * xmlXPathCastToString (xmlXPathObject *val); XMLPUBFUN xmlXPathObject * xmlXPathConvertBoolean (xmlXPathObject *val); XMLPUBFUN xmlXPathObject * xmlXPathConvertNumber (xmlXPathObject *val); XMLPUBFUN xmlXPathObject * xmlXPathConvertString (xmlXPathObject *val); /** * Context handling. */ XMLPUBFUN xmlXPathContext * xmlXPathNewContext (xmlDoc *doc); XMLPUBFUN void xmlXPathFreeContext (xmlXPathContext *ctxt); XMLPUBFUN void xmlXPathSetErrorHandler(xmlXPathContext *ctxt, xmlStructuredErrorFunc handler, void *context); XMLPUBFUN int xmlXPathContextSetCache(xmlXPathContext *ctxt, int active, int value, int options); /** * Evaluation functions. */ XMLPUBFUN long xmlXPathOrderDocElems (xmlDoc *doc); XMLPUBFUN int xmlXPathSetContextNode (xmlNode *node, xmlXPathContext *ctx); XMLPUBFUN xmlXPathObject * xmlXPathNodeEval (xmlNode *node, const xmlChar *str, xmlXPathContext *ctx); XMLPUBFUN xmlXPathObject * xmlXPathEval (const xmlChar *str, xmlXPathContext *ctx); XMLPUBFUN xmlXPathObject * xmlXPathEvalExpression (const xmlChar *str, xmlXPathContext *ctxt); XMLPUBFUN int xmlXPathEvalPredicate (xmlXPathContext *ctxt, xmlXPathObject *res); /** * Separate compilation/evaluation entry points. */ XMLPUBFUN xmlXPathCompExpr * xmlXPathCompile (const xmlChar *str); XMLPUBFUN xmlXPathCompExpr * xmlXPathCtxtCompile (xmlXPathContext *ctxt, const xmlChar *str); XMLPUBFUN xmlXPathObject * xmlXPathCompiledEval (xmlXPathCompExpr *comp, xmlXPathContext *ctx); XMLPUBFUN int xmlXPathCompiledEvalToBoolean(xmlXPathCompExpr *comp, xmlXPathContext *ctxt); XMLPUBFUN void xmlXPathFreeCompExpr (xmlXPathCompExpr *comp); XML_DEPRECATED XMLPUBFUN void xmlXPathInit (void); XMLPUBFUN int xmlXPathIsNaN (double val); XMLPUBFUN int xmlXPathIsInf (double val); #ifdef __cplusplus } #endif #endif /* LIBXML_XPATH_ENABLED */ #endif /* ! __XML_XPATH_H__ */
Save File
Cancel