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/**
* @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__ */
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