xref: /reactos/sdk/lib/3rdparty/libxml2/xlink.c (revision 1de09c47)
1 /*
2  * xlink.c : implementation of the hyperlinks detection module
3  *           This version supports both XML XLinks and HTML simple links
4  *
5  * See Copyright for the status of this software.
6  *
7  * daniel@veillard.com
8  */
9 
10 
11 #define IN_LIBXML
12 #include "libxml.h"
13 
14 #ifdef LIBXML_XPTR_ENABLED
15 #include <string.h> /* for memset() only */
16 #include <ctype.h>
17 #include <stdlib.h>
18 
19 #include <libxml/xmlmemory.h>
20 #include <libxml/tree.h>
21 #include <libxml/parser.h>
22 #include <libxml/valid.h>
23 #include <libxml/xlink.h>
24 #include <libxml/globals.h>
25 
26 #define XLINK_NAMESPACE (BAD_CAST "http://www.w3.org/1999/xlink/namespace/")
27 #define XHTML_NAMESPACE (BAD_CAST "http://www.w3.org/1999/xhtml/")
28 
29 /****************************************************************
30  *								*
31  *           Default setting and related functions		*
32  *								*
33  ****************************************************************/
34 
35 static xlinkHandlerPtr xlinkDefaultHandler = NULL;
36 static xlinkNodeDetectFunc	xlinkDefaultDetect = NULL;
37 
38 /**
39  * xlinkGetDefaultHandler:
40  *
41  * Get the default xlink handler.
42  *
43  * Returns the current xlinkHandlerPtr value.
44  */
45 xlinkHandlerPtr
46 xlinkGetDefaultHandler(void) {
47     return(xlinkDefaultHandler);
48 }
49 
50 
51 /**
52  * xlinkSetDefaultHandler:
53  * @handler:  the new value for the xlink handler block
54  *
55  * Set the default xlink handlers
56  */
57 void
58 xlinkSetDefaultHandler(xlinkHandlerPtr handler) {
59     xlinkDefaultHandler = handler;
60 }
61 
62 /**
63  * xlinkGetDefaultDetect:
64  *
65  * Get the default xlink detection routine
66  *
67  * Returns the current function or NULL;
68  */
69 xlinkNodeDetectFunc
70 xlinkGetDefaultDetect	(void) {
71     return(xlinkDefaultDetect);
72 }
73 
74 /**
75  * xlinkSetDefaultDetect:
76  * @func: pointer to the new detection routine.
77  *
78  * Set the default xlink detection routine
79  */
80 void
81 xlinkSetDefaultDetect	(xlinkNodeDetectFunc func) {
82     xlinkDefaultDetect = func;
83 }
84 
85 /****************************************************************
86  *								*
87  *                  The detection routines			*
88  *								*
89  ****************************************************************/
90 
91 
92 /**
93  * xlinkIsLink:
94  * @doc:  the document containing the node
95  * @node:  the node pointer itself
96  *
97  * Check whether the given node carries the attributes needed
98  * to be a link element (or is one of the linking elements issued
99  * from the (X)HTML DtDs).
100  * This routine don't try to do full checking of the link validity
101  * but tries to detect and return the appropriate link type.
102  *
103  * Returns the xlinkType of the node (XLINK_TYPE_NONE if there is no
104  *         link detected.
105  */
106 xlinkType
107 xlinkIsLink	(xmlDocPtr doc, xmlNodePtr node) {
108     xmlChar *type = NULL, *role = NULL;
109     xlinkType ret = XLINK_TYPE_NONE;
110 
111     if (node == NULL) return(XLINK_TYPE_NONE);
112     if (doc == NULL) doc = node->doc;
113     if ((doc != NULL) && (doc->type == XML_HTML_DOCUMENT_NODE)) {
114         /*
115 	 * This is an HTML document.
116 	 */
117     } else if ((node->ns != NULL) &&
118                (xmlStrEqual(node->ns->href, XHTML_NAMESPACE))) {
119 	/*
120 	 * !!!! We really need an IS_XHTML_ELEMENT function from HTMLtree.h @@@
121 	 */
122         /*
123 	 * This is an XHTML element within an XML document
124 	 * Check whether it's one of the element able to carry links
125 	 * and in that case if it holds the attributes.
126 	 */
127     }
128 
129     /*
130      * We don't prevent a-priori having XML Linking constructs on
131      * XHTML elements
132      */
133     type = xmlGetNsProp(node, BAD_CAST"type", XLINK_NAMESPACE);
134     if (type != NULL) {
135 	if (xmlStrEqual(type, BAD_CAST "simple")) {
136             ret = XLINK_TYPE_SIMPLE;
137 	} else if (xmlStrEqual(type, BAD_CAST "extended")) {
138 	    role = xmlGetNsProp(node, BAD_CAST "role", XLINK_NAMESPACE);
139 	    if (role != NULL) {
140 		xmlNsPtr xlink;
141 		xlink = xmlSearchNs(doc, node, XLINK_NAMESPACE);
142 		if (xlink == NULL) {
143 		    /* Humm, fallback method */
144 		    if (xmlStrEqual(role, BAD_CAST"xlink:external-linkset"))
145 			ret = XLINK_TYPE_EXTENDED_SET;
146 		} else {
147 		    xmlChar buf[200];
148 		    snprintf((char *) buf, sizeof(buf), "%s:external-linkset",
149 			     (char *) xlink->prefix);
150                     buf[sizeof(buf) - 1] = 0;
151 		    if (xmlStrEqual(role, buf))
152 			ret = XLINK_TYPE_EXTENDED_SET;
153 
154 		}
155 
156 	    }
157 	    ret = XLINK_TYPE_EXTENDED;
158 	}
159     }
160 
161     if (type != NULL) xmlFree(type);
162     if (role != NULL) xmlFree(role);
163     return(ret);
164 }
165 #endif /* LIBXML_XPTR_ENABLED */
166