1 /*****************************************************************************
2 * xtag.c : a trivial parser for XML-like tags
3 *****************************************************************************
4 * Copyright (C) 2003-2004 Commonwealth Scientific and Industrial Research
5 * Organisation (CSIRO) Australia
6 * Copyright (C) 2000-2004 VideoLAN
10 * Authors: Conrad Parker <Conrad.Parker@csiro.au>
11 * Andre Pang <Andre.Pang@csiro.au>
12 * Gildas Bazin <gbazin@videolan.org>
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
27 *****************************************************************************/
50 * struct XTag is kind of a union ... it normally represents a whole
51 * tag (and its children), but it could alternatively represent some
52 * PCDATA. Basically, if tag->pcdata is non-NULL, interpret only it and
53 * ignore the name, attributes and inner_tags.
65 typedef struct _XAttribute
71 typedef struct _XTagParser
73 int valid; /* boolean */
79 /*****************************************************************************
81 *****************************************************************************/
82 static int Open ( vlc_object_t * );
83 static void Close( vlc_object_t * );
86 set_category( CAT_ADVANCED );
87 set_subcategory( SUBCAT_ADVANCED_XML );
88 set_description( _("Simple XML Parser") );
89 set_capability( "xml", 5 );
90 set_callbacks( Open, Close );
93 struct xml_reader_sys_t
95 XTag *p_root; /* Root tag */
96 XTag *p_curtag; /* Current tag */
97 XList *p_curattr; /* Current attribute */
101 static xml_reader_t *ReaderCreate( xml_t *, const char * );
102 static void ReaderDelete( xml_reader_t * );
103 static int ReaderRead( xml_reader_t * );
104 static int ReaderNodeType( xml_reader_t * );
105 static char *ReaderName( xml_reader_t * );
106 static char *ReaderValue( xml_reader_t * );
107 static int ReaderNextAttr( xml_reader_t * );
109 static void CatalogLoad( xml_t *, const char * );
110 static void CatalogAdd( xml_t *, const char *, const char *, const char * );
112 static XTag *xtag_new_parse( const char *, int );
113 static char *xtag_get_name( XTag * );
114 static char *xtag_get_pcdata( XTag * );
115 static char *xtag_get_attribute( XTag *, char * );
116 static XTag *xtag_first_child( XTag *, char * );
117 static XTag *xtag_next_child( XTag *, char * );
118 static XTag *xtag_free( XTag * );
119 static int xtag_snprint( char *, int, XTag * );
121 /*****************************************************************************
122 * Module initialization
123 *****************************************************************************/
124 static int Open( vlc_object_t *p_this )
126 xml_t *p_xml = (xml_t *)p_this;
128 p_xml->pf_reader_create = ReaderCreate;
129 p_xml->pf_reader_delete = ReaderDelete;
131 p_xml->pf_catalog_load = CatalogLoad;
132 p_xml->pf_catalog_add = CatalogAdd;
137 /*****************************************************************************
138 * Module deinitialization
139 *****************************************************************************/
140 static void Close( vlc_object_t *p_this )
145 /*****************************************************************************
146 * Catalogue functions
147 *****************************************************************************/
148 static void CatalogLoad( xml_t *p_xml, const char *psz_filename )
150 msg_Dbg( p_xml, "catalog support not implemented" );
153 static void CatalogAdd( xml_t *p_xml, const char *psz_arg1,
154 const char *psz_arg2, const char *psz_filename )
158 /*****************************************************************************
160 *****************************************************************************/
161 static xml_reader_t *ReaderCreate( xml_t *p_xml, const char *psz_filename )
163 xml_reader_t *p_reader;
164 xml_reader_sys_t *p_sys;
170 /* Open and read file */
171 file = fopen( psz_filename, "rt" );
174 msg_Warn( p_xml, "could not open file '%s'", psz_filename );
178 fseek( file, 0L, SEEK_END );
179 i_buffer = ftell( file );
180 fseek( file, 0L, SEEK_SET );
181 p_buffer = malloc( i_buffer + 1 );
182 i_buffer = fread( p_buffer, 1, i_buffer, file );
183 p_buffer[i_buffer] = 0;
188 msg_Dbg( p_xml, "file '%s' is empty", psz_filename );
193 p_root = xtag_new_parse( p_buffer, i_buffer );
196 msg_Warn( p_xml, "couldn't parse file '%s'", psz_filename );
201 p_reader = malloc( sizeof(xml_reader_t) );
202 p_reader->p_sys = p_sys = malloc( sizeof(xml_reader_sys_t) );
203 p_reader->p_sys->p_root = p_root;
204 p_reader->p_sys->p_curtag = NULL;
205 p_reader->p_sys->p_curattr = NULL;
206 p_reader->p_sys->b_endtag = VLC_FALSE;
207 p_reader->p_xml = p_xml;
209 p_reader->pf_read = ReaderRead;
210 p_reader->pf_node_type = ReaderNodeType;
211 p_reader->pf_name = ReaderName;
212 p_reader->pf_value = ReaderValue;
213 p_reader->pf_next_attr = ReaderNextAttr;
218 static void ReaderDelete( xml_reader_t *p_reader )
220 xtag_free( p_reader->p_sys->p_root );
221 free( p_reader->p_sys );
225 static int ReaderRead( xml_reader_t *p_reader )
229 if( !p_reader->p_sys->p_curtag )
231 p_reader->p_sys->p_curtag = p_reader->p_sys->p_root;
237 if( (p_child = xtag_next_child( p_reader->p_sys->p_curtag, 0 )) )
239 p_reader->p_sys->p_curtag = p_child;
240 p_reader->p_sys->p_curattr = 0;
241 p_reader->p_sys->b_endtag = VLC_FALSE;
245 if( p_reader->p_sys->p_curtag->name && /* no end tag for pcdata */
246 !p_reader->p_sys->b_endtag )
248 p_reader->p_sys->b_endtag = VLC_TRUE;
252 p_reader->p_sys->b_endtag = VLC_FALSE;
253 if( !p_reader->p_sys->p_curtag->parent ) return 0;
254 p_reader->p_sys->p_curtag = p_reader->p_sys->p_curtag->parent;
260 static int ReaderNodeType( xml_reader_t *p_reader )
262 if( p_reader->p_sys->p_curtag->name &&
263 p_reader->p_sys->b_endtag ) return XML_READER_ENDELEM;
264 if( p_reader->p_sys->p_curtag->name ) return XML_READER_STARTELEM;
265 if( p_reader->p_sys->p_curtag->pcdata ) return XML_READER_TEXT;
266 return XML_READER_NONE;
269 static char *ReaderName( xml_reader_t *p_reader )
271 const char *psz_name;
273 if( !p_reader->p_sys->p_curattr )
275 psz_name = xtag_get_name( p_reader->p_sys->p_curtag );
277 printf( "TAG: %s\n", psz_name );
281 psz_name = ((XAttribute *)p_reader->p_sys->p_curattr->data)->name;
283 if( psz_name ) return strdup( psz_name );
287 static char *ReaderValue( xml_reader_t *p_reader )
289 const char *psz_name;
291 if( !p_reader->p_sys->p_curattr ) return 0;
294 printf( "%s=%s\n", ((XAttribute *)p_reader->p_sys->p_curattr->data)->name,
295 ((XAttribute *)p_reader->p_sys->p_curattr->data)->value );
298 psz_name = ((XAttribute *)p_reader->p_sys->p_curattr->data)->value;
300 if( psz_name ) return strdup( psz_name );
304 static int ReaderNextAttr( xml_reader_t *p_reader )
306 if( !p_reader->p_sys->p_curattr )
307 p_reader->p_sys->p_curattr = p_reader->p_sys->p_curtag->attributes;
308 else if( p_reader->p_sys->p_curattr )
309 p_reader->p_sys->p_curattr = p_reader->p_sys->p_curattr->next;
311 if( p_reader->p_sys->p_curattr ) return VLC_SUCCESS;
312 else return VLC_EGENERIC;
315 /*****************************************************************************
316 * XTAG parser functions
317 *****************************************************************************/
319 static XList *xlist_append( XList *list, void *data )
323 l = (XList *)malloc( sizeof(XList) );
324 l->prev = l->next = NULL;
327 if( list == NULL ) return l;
329 for( last = list; last; last = last->next )
330 if( last->next == NULL ) break;
332 if( last ) last->next = l;
337 static void xlist_free( XList *list )
341 for( l = list; l; l = ln )
348 /* Character classes */
350 #define X_WHITESPACE 1<<0
351 #define X_OPENTAG 1<<1
352 #define X_CLOSETAG 1<<2
353 #define X_DQUOTE 1<<3
354 #define X_SQUOTE 1<<4
360 static int xtag_cin( char c, int char_class )
362 if( char_class & X_WHITESPACE ) if( isspace(c) ) return VLC_TRUE;
363 if( char_class & X_OPENTAG ) if( c == '<' ) return VLC_TRUE;
364 if( char_class & X_CLOSETAG ) if( c == '>' ) return VLC_TRUE;
365 if( char_class & X_DQUOTE ) if( c == '"' ) return VLC_TRUE;
366 if( char_class & X_SQUOTE ) if( c == '\'' ) return VLC_TRUE;
367 if( char_class & X_EQUAL ) if( c == '=' ) return VLC_TRUE;
368 if( char_class & X_SLASH ) if( c == '/' ) return VLC_TRUE;
369 if( char_class & X_QMARK ) if( c == '!' ) return VLC_TRUE;
370 if( char_class & X_DASH ) if( c == '-' ) return VLC_TRUE;
375 static int xtag_index( XTagParser *parser, int char_class )
377 char *s = parser->start;
380 for( i = 0; s[i] && s != parser->end; i++ )
382 if( xtag_cin( s[i], char_class ) ) return i;
388 static void xtag_skip_over( XTagParser *parser, int char_class )
390 char *s = parser->start;
393 if( !parser->valid ) return;
395 for( i = 0; s[i] && s != parser->end; i++ )
397 if( !xtag_cin( s[i], char_class ) )
399 parser->start = &s[i];
407 static void xtag_skip_whitespace( XTagParser * parser )
409 xtag_skip_over( parser, X_WHITESPACE );
412 static char *xtag_slurp_to( XTagParser *parser, int good_end, int bad_end )
414 char *ret, *s = parser->start;
417 if( !parser->valid ) return NULL;
419 xi = xtag_index( parser, good_end | bad_end );
421 if( xi > 0 && xtag_cin (s[xi], good_end) )
423 ret = malloc( (xi+1) * sizeof(char) );
424 strncpy( ret, s, xi );
426 parser->start = &s[xi];
433 static int xtag_assert_and_pass( XTagParser *parser, int char_class )
435 char *s = parser->start;
437 if( !parser->valid ) return VLC_FALSE;
439 if( !xtag_cin( s[0], char_class ) )
441 parser->valid = VLC_FALSE;
445 parser->start = &s[1];
450 static char *xtag_slurp_quoted( XTagParser *parser )
453 int quote = X_DQUOTE; /* quote char to match on */
456 if( !parser->valid ) return NULL;
458 xtag_skip_whitespace( parser );
462 if( xtag_cin( s[0], X_SQUOTE ) ) quote = X_SQUOTE;
464 if( !xtag_assert_and_pass( parser, quote ) ) return NULL;
468 for( xi = 0; s[xi]; xi++ )
470 if( xtag_cin( s[xi], quote ) )
472 if( !(xi > 1 && s[xi-1] == '\\') ) break;
476 ret = malloc( (xi+1) * sizeof(char) );
477 strncpy( ret, s, xi );
479 parser->start = &s[xi];
481 if( !xtag_assert_and_pass( parser, quote ) ) return NULL;
486 static XAttribute *xtag_parse_attribute( XTagParser *parser )
492 if( !parser->valid ) return NULL;
494 xtag_skip_whitespace( parser );
496 name = xtag_slurp_to( parser, X_WHITESPACE|X_EQUAL, X_SLASH|X_CLOSETAG );
497 if( name == NULL ) return NULL;
499 xtag_skip_whitespace( parser );
502 if( !xtag_assert_and_pass( parser, X_EQUAL ) )
505 printf( "xtag: attr failed EQUAL on <%s>\n", name );
510 xtag_skip_whitespace( parser );
512 value = xtag_slurp_quoted( parser );
517 printf ("Got NULL quoted attribute value\n");
522 attr = malloc( sizeof (*attr) );
529 parser->valid = VLC_FALSE;
533 static XTag *xtag_parse_tag( XTagParser *parser )
541 if( !parser->valid ) return NULL;
543 #if 0 /* Do we really want all the whitespace pcdata ? */
544 xtag_skip_whitespace( parser );
547 if( (pcdata = xtag_slurp_to( parser, X_OPENTAG, X_NONE )) != NULL )
549 tag = malloc( sizeof(*tag) );
551 tag->pcdata = pcdata;
552 tag->parent = parser->current_tag;
553 tag->attributes = NULL;
554 tag->children = NULL;
555 tag->current_child = NULL;
562 /* if this starts a close tag, return NULL and let the parent take it */
563 if( xtag_cin( s[0], X_OPENTAG ) && xtag_cin( s[1], X_SLASH ) )
566 /* if this starts a comment tag, skip until end */
567 if( xtag_cin( s[0], X_OPENTAG ) && xtag_cin( s[1], X_QMARK ) &&
568 xtag_cin( s[2], X_DASH ) && xtag_cin( s[3], X_DASH ) )
572 parser->start = s = &s[4];
574 while( (xi = xtag_index( parser, X_DASH )) >= 0 )
576 parser->start = s = &s[xi+1];
578 if( xtag_cin( s[0], X_DASH ) && xtag_cin( s[1], X_CLOSETAG ) )
580 parser->start = &s[2];
581 xtag_skip_whitespace( parser );
582 return xtag_parse_tag( parser );
589 /* FIXME: if this starts a DOCTYPE tag, skip until end */
590 if( xtag_cin( s[0], X_OPENTAG ) && xtag_cin( s[1], X_QMARK ) )
592 int xi = xtag_index( parser, X_CLOSETAG );
593 if( xi <= 0 ) return NULL;
595 parser->start = &s[xi+1];
596 xtag_skip_whitespace( parser );
597 return xtag_parse_tag( parser );
600 if( !xtag_assert_and_pass( parser, X_OPENTAG ) ) return NULL;
602 name = xtag_slurp_to( parser, X_WHITESPACE|X_SLASH|X_CLOSETAG, X_NONE );
603 if( name == NULL ) return NULL;
606 printf ("<%s ...\n", name);
609 tag = malloc( sizeof(*tag) );
612 tag->parent = parser->current_tag;
613 tag->attributes = NULL;
614 tag->children = NULL;
615 tag->current_child = NULL;
619 if( xtag_cin( s[0], X_WHITESPACE ) )
621 while( (attr = xtag_parse_attribute( parser )) != NULL )
623 tag->attributes = xlist_append( tag->attributes, attr );
627 xtag_skip_whitespace( parser );
631 if( xtag_cin( s[0], X_CLOSETAG ) )
633 parser->current_tag = tag;
635 xtag_assert_and_pass( parser, X_CLOSETAG );
637 while( (inner = xtag_parse_tag( parser ) ) != NULL )
639 tag->children = xlist_append( tag->children, inner );
642 parser->current_tag = tag->parent;
643 xtag_skip_whitespace( parser );
645 xtag_assert_and_pass( parser, X_OPENTAG );
646 xtag_assert_and_pass( parser, X_SLASH );
647 name = xtag_slurp_to( parser, X_WHITESPACE | X_CLOSETAG, X_NONE );
650 if( strcmp( name, tag->name ) )
653 printf ("got %s expected %s\n", name, tag->name);
655 parser->valid = VLC_FALSE;
660 xtag_skip_whitespace( parser );
661 xtag_assert_and_pass( parser, X_CLOSETAG );
666 xtag_assert_and_pass( parser, X_SLASH );
667 xtag_assert_and_pass( parser, X_CLOSETAG );
673 static XTag *xtag_free( XTag *xtag )
679 if( xtag == NULL ) return NULL;
681 if( xtag->name ) free( xtag->name );
682 if( xtag->pcdata ) free( xtag->pcdata );
684 for( l = xtag->attributes; l; l = l->next )
686 if( (attr = (XAttribute *)l->data) != NULL )
688 if( attr->name ) free( attr->name );
689 if( attr->value ) free( attr->value );
693 xlist_free( xtag->attributes );
695 for( l = xtag->children; l; l = l->next )
697 child = (XTag *)l->data;
700 xlist_free( xtag->children );
707 static XTag *xtag_new_parse( const char *s, int n )
710 XTag *tag, *ttag, *wrapper;
712 parser.valid = VLC_TRUE;
713 parser.current_tag = NULL;
714 parser.start = (char *)s;
716 if( n == -1 ) parser.end = NULL;
717 else if( n == 0 ) return NULL;
718 else parser.end = (char *)&s[n];
720 tag = xtag_parse_tag( &parser );
728 if( (ttag = xtag_parse_tag( &parser )) != NULL )
736 wrapper = malloc( sizeof(XTag) );
737 wrapper->name = NULL;
738 wrapper->pcdata = NULL;
739 wrapper->parent = NULL;
740 wrapper->attributes = NULL;
741 wrapper->children = NULL;
742 wrapper->current_child = NULL;
744 wrapper->children = xlist_append( wrapper->children, tag );
745 wrapper->children = xlist_append( wrapper->children, ttag );
747 while( (ttag = xtag_parse_tag( &parser )) != NULL )
755 wrapper->children = xlist_append( wrapper->children, ttag );
763 static char *xtag_get_name( XTag *xtag )
765 return xtag ? xtag->name : NULL;
768 static char *xtag_get_pcdata( XTag *xtag )
773 if( xtag == NULL ) return NULL;
775 for( l = xtag->children; l; l = l->next )
777 child = (XTag *)l->data;
778 if( child->pcdata != NULL )
780 return child->pcdata;
787 static char *xtag_get_attribute( XTag *xtag, char *attribute )
792 if( xtag == NULL ) return NULL;
794 for( l = xtag->attributes; l; l = l->next )
796 if( (attr = (XAttribute *)l->data) != NULL )
798 if( !strcmp( attr->name, attribute ) ) return attr->value;
805 static XTag *xtag_first_child( XTag *xtag, char *name )
810 if( xtag == NULL ) return NULL;
811 if( (l = xtag->children) == NULL ) return NULL;
815 xtag->current_child = l;
816 return (XTag *)l->data;
819 for( ; l; l = l->next )
821 child = (XTag *)l->data;
823 if( !strcmp( child->name, name ) )
825 xtag->current_child = l;
830 xtag->current_child = NULL;
835 static XTag *xtag_next_child( XTag *xtag, char *name )
840 if( xtag == NULL ) return NULL;
842 if( (l = xtag->current_child) == NULL )
843 return xtag_first_child( xtag, name );
845 if( (l = l->next) == NULL ) return NULL;
849 xtag->current_child = l;
850 return (XTag *)l->data;
853 for( ; l; l = l->next )
855 child = (XTag *)l->data;
857 if( !strcmp( child->name, name ) )
859 xtag->current_child = l;
864 xtag->current_child = NULL;
870 * This snprints function takes a variable list of char *, the last of
871 * which must be NULL, and prints each in turn to buf.
872 * Returns C99-style total length that would have been written, even if
873 * this is larger than n.
875 static int xtag_snprints( char *buf, int n, ... )
879 int len, to_copy, total = 0;
883 for( s = va_arg( ap, char * ); s; s = va_arg( ap, char *) )
887 if( (to_copy = __MIN(n, len) ) > 0 )
889 memcpy( buf, s, to_copy );
902 static int xtag_snprint( char *buf, int n, XTag *xtag )
910 buf += __MIN(n, N); \
916 if( n > 0 ) buf[0] = '\0';
922 nn = xtag_snprints( buf, n, xtag->pcdata, NULL );
930 nn = xtag_snprints( buf, n, "<", xtag->name, NULL );
933 for( l = xtag->attributes; l; l = l->next )
935 attr = (XAttribute *)l->data;
937 nn = xtag_snprints( buf, n, " ", attr->name, "=\"", attr->value,
942 if( xtag->children == NULL )
944 nn = xtag_snprints ( buf, n, "/>", NULL );
950 nn = xtag_snprints( buf, n, ">", NULL );
954 for( l = xtag->children; l; l = l->next )
956 child = (XTag *)l->data;
958 nn = xtag_snprint( buf, n, child );
964 nn = xtag_snprints( buf, n, "</", xtag->name, ">", NULL );