2 * Summary: XML Path Language implementation
3 * Description: API for the XML Path Language implementation
5 * XML Path Language implementation
6 * XPath is a language for addressing parts of an XML document,
7 * designed to be used by both XSLT and XPointer
8 * http://www.w3.org/TR/xpath
11 * W3C Recommendation 16 November 1999
12 * http://www.w3.org/TR/1999/REC-xpath-19991116
14 * Copy: See Copyright for the status of this software.
16 * Author: Daniel Veillard
19 #ifndef __XML_XPATH_H__
20 #define __XML_XPATH_H__
22 #include <libxml/xmlversion.h>
24 #ifdef LIBXML_XPATH_ENABLED
26 #include <libxml/xmlerror.h>
27 #include <libxml/tree.h>
28 #include <libxml/hash.h>
29 #endif /* LIBXML_XPATH_ENABLED */
31 #if defined(LIBXML_XPATH_ENABLED) || defined(LIBXML_SCHEMAS_ENABLED)
35 #endif /* LIBXML_XPATH_ENABLED or LIBXML_SCHEMAS_ENABLED */
37 #ifdef LIBXML_XPATH_ENABLED
39 typedef struct _xmlXPathContext xmlXPathContext;
40 typedef xmlXPathContext *xmlXPathContextPtr;
41 typedef struct _xmlXPathParserContext xmlXPathParserContext;
42 typedef xmlXPathParserContext *xmlXPathParserContextPtr;
45 * The set of XPath error codes.
49 XPATH_EXPRESSION_OK = 0,
51 XPATH_UNFINISHED_LITERAL_ERROR,
52 XPATH_START_LITERAL_ERROR,
53 XPATH_VARIABLE_REF_ERROR,
54 XPATH_UNDEF_VARIABLE_ERROR,
55 XPATH_INVALID_PREDICATE_ERROR,
58 XPATH_UNKNOWN_FUNC_ERROR,
59 XPATH_INVALID_OPERAND,
62 XPATH_INVALID_CTXT_SIZE,
63 XPATH_INVALID_CTXT_POSITION,
67 XPTR_SUB_RESOURCE_ERROR,
68 XPATH_UNDEF_PREFIX_ERROR,
70 XPATH_INVALID_CHAR_ERROR,
75 * A node-set (an unordered collection of nodes without duplicates).
77 typedef struct _xmlNodeSet xmlNodeSet;
78 typedef xmlNodeSet *xmlNodeSetPtr;
80 int nodeNr; /* number of nodes in the set */
81 int nodeMax; /* size of the array as allocated */
82 xmlNodePtr *nodeTab; /* array of nodes in no particular order */
83 /* @@ with_ns to check wether namespace nodes should be looked at @@ */
87 * An expression is evaluated to yield an object, which
88 * has one of the following four basic types:
94 * @@ XPointer will add more types !
105 XPATH_LOCATIONSET = 7,
107 XPATH_XSLT_TREE = 9 /* An XSLT value tree, non modifiable */
108 } xmlXPathObjectType;
110 typedef struct _xmlXPathObject xmlXPathObject;
111 typedef xmlXPathObject *xmlXPathObjectPtr;
112 struct _xmlXPathObject {
113 xmlXPathObjectType type;
114 xmlNodeSetPtr nodesetval;
125 * xmlXPathConvertFunc:
126 * @obj: an XPath object
127 * @type: the number of the target type
129 * A conversion function is associated to a type and used to cast
130 * the new type to primitive values.
132 * Returns -1 in case of error, 0 otherwise
134 typedef int (*xmlXPathConvertFunc) (xmlXPathObjectPtr obj, int type);
137 * Extra type: a name and a conversion function.
140 typedef struct _xmlXPathType xmlXPathType;
141 typedef xmlXPathType *xmlXPathTypePtr;
142 struct _xmlXPathType {
143 const xmlChar *name; /* the type name */
144 xmlXPathConvertFunc func; /* the conversion function */
148 * Extra variable: a name and a value.
151 typedef struct _xmlXPathVariable xmlXPathVariable;
152 typedef xmlXPathVariable *xmlXPathVariablePtr;
153 struct _xmlXPathVariable {
154 const xmlChar *name; /* the variable name */
155 xmlXPathObjectPtr value; /* the value */
160 * @ctxt: an XPath parser context
161 * @nargs: the number of arguments passed to the function
163 * An XPath evaluation function, the parameters are on the XPath context stack.
166 typedef void (*xmlXPathEvalFunc)(xmlXPathParserContextPtr ctxt,
170 * Extra function: a name and a evaluation function.
173 typedef struct _xmlXPathFunct xmlXPathFunct;
174 typedef xmlXPathFunct *xmlXPathFuncPtr;
175 struct _xmlXPathFunct {
176 const xmlChar *name; /* the function name */
177 xmlXPathEvalFunc func; /* the evaluation function */
182 * @ctxt: the XPath interpreter context
183 * @cur: the previous node being explored on that axis
185 * An axis traversal function. To traverse an axis, the engine calls
186 * the first time with cur == NULL and repeat until the function returns
187 * NULL indicating the end of the axis traversal.
189 * Returns the next node in that axis or NULL if at the end of the axis.
192 typedef xmlXPathObjectPtr (*xmlXPathAxisFunc) (xmlXPathParserContextPtr ctxt,
193 xmlXPathObjectPtr cur);
196 * Extra axis: a name and an axis function.
199 typedef struct _xmlXPathAxis xmlXPathAxis;
200 typedef xmlXPathAxis *xmlXPathAxisPtr;
201 struct _xmlXPathAxis {
202 const xmlChar *name; /* the axis name */
203 xmlXPathAxisFunc func; /* the search function */
208 * @ctxt: the XPath interprestation context
209 * @nargs: the number of arguments
212 * The arguments (if any) are popped out from the context stack
213 * and the result is pushed on the stack.
216 typedef void (*xmlXPathFunction) (xmlXPathParserContextPtr ctxt, int nargs);
219 * Function and Variable Lookup.
223 * xmlXPathVariableLookupFunc:
224 * @ctxt: an XPath context
225 * @name: name of the variable
226 * @ns_uri: the namespace name hosting this variable
228 * Prototype for callbacks used to plug variable lookup in the XPath
231 * Returns the XPath object value or NULL if not found.
233 typedef xmlXPathObjectPtr (*xmlXPathVariableLookupFunc) (void *ctxt,
235 const xmlChar *ns_uri);
238 * xmlXPathFuncLookupFunc:
239 * @ctxt: an XPath context
240 * @name: name of the function
241 * @ns_uri: the namespace name hosting this function
243 * Prototype for callbacks used to plug function lookup in the XPath
246 * Returns the XPath function or NULL if not found.
248 typedef xmlXPathFunction (*xmlXPathFuncLookupFunc) (void *ctxt,
250 const xmlChar *ns_uri);
254 * Flags for XPath engine compilation and runtime
259 * check namespaces at compilation
261 #define XML_XPATH_CHECKNS (1<<0)
265 * forbid variables in expression
267 #define XML_XPATH_NOVAR (1<<1)
272 * Expression evaluation occurs with respect to a context.
273 * he context consists of:
274 * - a node (the context node)
275 * - a node list (the context node list)
276 * - a set of variable bindings
277 * - a function library
278 * - the set of namespace declarations in scope for the expression
279 * Following the switch to hash tables, this need to be trimmed up at
280 * the next binary incompatible release.
281 * The node may be modified when the context is passed to libxml2
282 * for an XPath evaluation so you may need to initialize it again
283 * before the next call.
286 struct _xmlXPathContext {
287 xmlDocPtr doc; /* The current document */
288 xmlNodePtr node; /* The current node */
290 int nb_variables_unused; /* unused (hash table) */
291 int max_variables_unused; /* unused (hash table) */
292 xmlHashTablePtr varHash; /* Hash table of defined variables */
294 int nb_types; /* number of defined types */
295 int max_types; /* max number of types */
296 xmlXPathTypePtr types; /* Array of defined types */
298 int nb_funcs_unused; /* unused (hash table) */
299 int max_funcs_unused; /* unused (hash table) */
300 xmlHashTablePtr funcHash; /* Hash table of defined funcs */
302 int nb_axis; /* number of defined axis */
303 int max_axis; /* max number of axis */
304 xmlXPathAxisPtr axis; /* Array of defined axis */
306 /* the namespace nodes of the context node */
307 xmlNsPtr *namespaces; /* Array of namespaces */
308 int nsNr; /* number of namespace in scope */
309 void *user; /* function to free */
311 /* extra variables */
312 int contextSize; /* the context size */
313 int proximityPosition; /* the proximity position */
315 /* extra stuff for XPointer */
316 int xptr; /* is this an XPointer context? */
317 xmlNodePtr here; /* for here() */
318 xmlNodePtr origin; /* for origin() */
320 /* the set of namespace declarations in scope for the expression */
321 xmlHashTablePtr nsHash; /* The namespaces hash table */
322 xmlXPathVariableLookupFunc varLookupFunc;/* variable lookup func */
323 void *varLookupData; /* variable lookup data */
325 /* Possibility to link in an extra item */
326 void *extra; /* needed for XSLT */
328 /* The function name and URI when calling a function */
329 const xmlChar *function;
330 const xmlChar *functionURI;
332 /* function lookup function and data */
333 xmlXPathFuncLookupFunc funcLookupFunc;/* function lookup func */
334 void *funcLookupData; /* function lookup data */
336 /* temporary namespace lists kept for walking the namespace axis */
337 xmlNsPtr *tmpNsList; /* Array of namespaces */
338 int tmpNsNr; /* number of namespaces in scope */
340 /* error reporting mechanism */
341 void *userData; /* user specific data block */
342 xmlStructuredErrorFunc error; /* the callback in case of errors */
343 xmlError lastError; /* the last error */
344 xmlNodePtr debugNode; /* the source node XSLT */
347 xmlDictPtr dict; /* dictionary if any */
349 int flags; /* flags to control compilation */
351 /* Cache for reusal of XPath objects */
356 * The structure of a compiled expression form is not public.
359 typedef struct _xmlXPathCompExpr xmlXPathCompExpr;
360 typedef xmlXPathCompExpr *xmlXPathCompExprPtr;
363 * xmlXPathParserContext:
365 * An XPath parser context. It contains pure parsing informations,
366 * an xmlXPathContext, and the stack of objects.
368 struct _xmlXPathParserContext {
369 const xmlChar *cur; /* the current char being parsed */
370 const xmlChar *base; /* the full expression */
372 int error; /* error code */
374 xmlXPathContextPtr context; /* the evaluation context */
375 xmlXPathObjectPtr value; /* the current value */
376 int valueNr; /* number of values stacked */
377 int valueMax; /* max number of values stacked */
378 xmlXPathObjectPtr *valueTab; /* stack of values */
380 xmlXPathCompExprPtr comp; /* the precompiled expression */
381 int xptr; /* it this an XPointer expression */
382 xmlNodePtr ancestor; /* used for walking preceding axis */
385 /************************************************************************
389 ************************************************************************/
392 * Objects and Nodesets handling
395 XMLPUBVAR double xmlXPathNAN;
396 XMLPUBVAR double xmlXPathPINF;
397 XMLPUBVAR double xmlXPathNINF;
399 /* These macros may later turn into functions */
401 * xmlXPathNodeSetGetLength:
404 * Implement a functionality similar to the DOM NodeList.length.
406 * Returns the number of nodes in the node-set.
408 #define xmlXPathNodeSetGetLength(ns) ((ns) ? (ns)->nodeNr : 0)
410 * xmlXPathNodeSetItem:
412 * @index: index of a node in the set
414 * Implements a functionality similar to the DOM NodeList.item().
416 * Returns the xmlNodePtr at the given @index in @ns or NULL if
417 * @index is out of range (0 to length-1)
419 #define xmlXPathNodeSetItem(ns, index) \
420 ((((ns) != NULL) && \
421 ((index) >= 0) && ((index) < (ns)->nodeNr)) ? \
422 (ns)->nodeTab[(index)] \
425 * xmlXPathNodeSetIsEmpty:
428 * Checks whether @ns is empty or not.
430 * Returns %TRUE if @ns is an empty node-set.
432 #define xmlXPathNodeSetIsEmpty(ns) \
433 (((ns) == NULL) || ((ns)->nodeNr == 0) || ((ns)->nodeTab == NULL))
436 XMLPUBFUN void XMLCALL
437 xmlXPathFreeObject (xmlXPathObjectPtr obj);
438 XMLPUBFUN xmlNodeSetPtr XMLCALL
439 xmlXPathNodeSetCreate (xmlNodePtr val);
440 XMLPUBFUN void XMLCALL
441 xmlXPathFreeNodeSetList (xmlXPathObjectPtr obj);
442 XMLPUBFUN void XMLCALL
443 xmlXPathFreeNodeSet (xmlNodeSetPtr obj);
444 XMLPUBFUN xmlXPathObjectPtr XMLCALL
445 xmlXPathObjectCopy (xmlXPathObjectPtr val);
446 XMLPUBFUN int XMLCALL
447 xmlXPathCmpNodes (xmlNodePtr node1,
450 * Conversion functions to basic types.
452 XMLPUBFUN int XMLCALL
453 xmlXPathCastNumberToBoolean (double val);
454 XMLPUBFUN int XMLCALL
455 xmlXPathCastStringToBoolean (const xmlChar * val);
456 XMLPUBFUN int XMLCALL
457 xmlXPathCastNodeSetToBoolean(xmlNodeSetPtr ns);
458 XMLPUBFUN int XMLCALL
459 xmlXPathCastToBoolean (xmlXPathObjectPtr val);
461 XMLPUBFUN double XMLCALL
462 xmlXPathCastBooleanToNumber (int val);
463 XMLPUBFUN double XMLCALL
464 xmlXPathCastStringToNumber (const xmlChar * val);
465 XMLPUBFUN double XMLCALL
466 xmlXPathCastNodeToNumber (xmlNodePtr node);
467 XMLPUBFUN double XMLCALL
468 xmlXPathCastNodeSetToNumber (xmlNodeSetPtr ns);
469 XMLPUBFUN double XMLCALL
470 xmlXPathCastToNumber (xmlXPathObjectPtr val);
472 XMLPUBFUN xmlChar * XMLCALL
473 xmlXPathCastBooleanToString (int val);
474 XMLPUBFUN xmlChar * XMLCALL
475 xmlXPathCastNumberToString (double val);
476 XMLPUBFUN xmlChar * XMLCALL
477 xmlXPathCastNodeToString (xmlNodePtr node);
478 XMLPUBFUN xmlChar * XMLCALL
479 xmlXPathCastNodeSetToString (xmlNodeSetPtr ns);
480 XMLPUBFUN xmlChar * XMLCALL
481 xmlXPathCastToString (xmlXPathObjectPtr val);
483 XMLPUBFUN xmlXPathObjectPtr XMLCALL
484 xmlXPathConvertBoolean (xmlXPathObjectPtr val);
485 XMLPUBFUN xmlXPathObjectPtr XMLCALL
486 xmlXPathConvertNumber (xmlXPathObjectPtr val);
487 XMLPUBFUN xmlXPathObjectPtr XMLCALL
488 xmlXPathConvertString (xmlXPathObjectPtr val);
493 XMLPUBFUN xmlXPathContextPtr XMLCALL
494 xmlXPathNewContext (xmlDocPtr doc);
495 XMLPUBFUN void XMLCALL
496 xmlXPathFreeContext (xmlXPathContextPtr ctxt);
497 XMLPUBFUN int XMLCALL
498 xmlXPathContextSetCache(xmlXPathContextPtr ctxt,
503 * Evaluation functions.
505 XMLPUBFUN long XMLCALL
506 xmlXPathOrderDocElems (xmlDocPtr doc);
507 XMLPUBFUN xmlXPathObjectPtr XMLCALL
508 xmlXPathEval (const xmlChar *str,
509 xmlXPathContextPtr ctx);
510 XMLPUBFUN xmlXPathObjectPtr XMLCALL
511 xmlXPathEvalExpression (const xmlChar *str,
512 xmlXPathContextPtr ctxt);
513 XMLPUBFUN int XMLCALL
514 xmlXPathEvalPredicate (xmlXPathContextPtr ctxt,
515 xmlXPathObjectPtr res);
517 * Separate compilation/evaluation entry points.
519 XMLPUBFUN xmlXPathCompExprPtr XMLCALL
520 xmlXPathCompile (const xmlChar *str);
521 XMLPUBFUN xmlXPathCompExprPtr XMLCALL
522 xmlXPathCtxtCompile (xmlXPathContextPtr ctxt,
524 XMLPUBFUN xmlXPathObjectPtr XMLCALL
525 xmlXPathCompiledEval (xmlXPathCompExprPtr comp,
526 xmlXPathContextPtr ctx);
527 XMLPUBFUN int XMLCALL
528 xmlXPathCompiledEvalToBoolean(xmlXPathCompExprPtr comp,
529 xmlXPathContextPtr ctxt);
530 XMLPUBFUN void XMLCALL
531 xmlXPathFreeCompExpr (xmlXPathCompExprPtr comp);
532 #endif /* LIBXML_XPATH_ENABLED */
533 #if defined(LIBXML_XPATH_ENABLED) || defined(LIBXML_SCHEMAS_ENABLED)
534 XMLPUBFUN void XMLCALL
536 XMLPUBFUN int XMLCALL
537 xmlXPathIsNaN (double val);
538 XMLPUBFUN int XMLCALL
539 xmlXPathIsInf (double val);
545 #endif /* LIBXML_XPATH_ENABLED or LIBXML_SCHEMAS_ENABLED*/
546 #endif /* ! __XML_XPATH_H__ */