xlink.c

Go to the documentation of this file.

/*
 * xlink.c : implementation of the hyperlinks detection module
 *           This version supports both XML XLinks and HTML simple links
 *
 * See Copyright for the status of this software.
 *
 * daniel@veillard.com
 */
 
 
#define IN_LIBXML
#include "libxml.h"
 
#ifdef LIBXML_XPTR_ENABLED
#include <string.h> /* for memset() only */
#include <ctype.h>
#include <stdlib.h>
 
#include <libxml/xmlmemory.h>
#include <libxml/tree.h>
#include <libxml/parser.h>
#include <libxml/valid.h>
#include <libxml/xlink.h>
#include <libxml/globals.h>
 
#define XLINK_NAMESPACE (BAD_CAST "http://www.w3.org/1999/xlink/namespace/")
#define XHTML_NAMESPACE (BAD_CAST "http://www.w3.org/1999/xhtml/")
 
/****************************************************************
 *                              *
 *           Default setting and related functions      *
 *                              *
 ****************************************************************/
 
static xlinkHandlerPtr xlinkDefaultHandler = NULL;
static xlinkNodeDetectFunc  xlinkDefaultDetect = NULL;
 
xlinkHandlerPtr
xlinkGetDefaultHandler(void) {
    return(xlinkDefaultHandler);
}
 
 
void
xlinkSetDefaultHandler(xlinkHandlerPtr handler) {
    xlinkDefaultHandler = handler;
}
 
xlinkNodeDetectFunc
xlinkGetDefaultDetect   (void) {
    return(xlinkDefaultDetect);
}
 
void
xlinkSetDefaultDetect   (xlinkNodeDetectFunc func) {
    xlinkDefaultDetect = func;
}
 
/****************************************************************
 *                              *
 *                  The detection routines          *
 *                              *
 ****************************************************************/
 
 
xlinkType
xlinkIsLink (xmlDocPtr doc, xmlNodePtr node) {
    xmlChar *type = NULL, *role = NULL;
    xlinkType ret = XLINK_TYPE_NONE;
 
    if (node == NULL) return(XLINK_TYPE_NONE);
    if (doc == NULL) doc = node->doc;
    if ((doc != NULL) && (doc->type == XML_HTML_DOCUMENT_NODE)) {
        /*
     * This is an HTML document.
     */
    } else if ((node->ns != NULL) &&
               (xmlStrEqual(node->ns->href, XHTML_NAMESPACE))) {
    /*
     * !!!! We really need an IS_XHTML_ELEMENT function from HTMLtree.h @@@
     */
        /*
     * This is an XHTML element within an XML document
     * Check whether it's one of the element able to carry links
     * and in that case if it holds the attributes.
     */
    }
 
    /*
     * We don't prevent a-priori having XML Linking constructs on
     * XHTML elements
     */
    type = xmlGetNsProp(node, BAD_CAST"type", XLINK_NAMESPACE);
    if (type != NULL) {
    if (xmlStrEqual(type, BAD_CAST "simple")) {
            ret = XLINK_TYPE_SIMPLE;
    } else if (xmlStrEqual(type, BAD_CAST "extended")) {
        role = xmlGetNsProp(node, BAD_CAST "role", XLINK_NAMESPACE);
        if (role != NULL) {
        xmlNsPtr xlink;
        xlink = xmlSearchNs(doc, node, XLINK_NAMESPACE);
        if (xlink == NULL) {
            /* Humm, fallback method */
            if (xmlStrEqual(role, BAD_CAST"xlink:external-linkset"))
            ret = XLINK_TYPE_EXTENDED_SET;
        } else {
            xmlChar buf[200];
            snprintf((char *) buf, sizeof(buf), "%s:external-linkset",
                 (char *) xlink->prefix);
                    buf[sizeof(buf) - 1] = 0;
            if (xmlStrEqual(role, buf))
            ret = XLINK_TYPE_EXTENDED_SET;
 
        }
 
        }
        ret = XLINK_TYPE_EXTENDED;
    }
    }
 
    if (type != NULL) xmlFree(type);
    if (role != NULL) xmlFree(role);
    return(ret);
}
#endif /* LIBXML_XPTR_ENABLED */