[Expat-discuss] (no subject)

[Mark Thomson]

>Expat relies on volunteer work, so if you find a nice way to do that, why not share it with the community?

OK.. here's the function. I tested it only three times: 

(1) Parser is created without namespace processing (it returns 0--
    no need to check if `parser->m_ns' is FALSE) 
(2) prefix == 0 (Returns default namespace or 0 if no default 
    namespace was specified) 
(3) prefix != 0 (Get namespace corresponding to `prefix' or 0 if no  
    namespace corresponds to the given prefix).

I think I am not wrong about the following 2 points:

- The default namespace is not stored in its own variable. Instead, 
  it is stored as part of the element type name (i.e., there is no
  nul-terminated default namespace stored anywhere). 

- Every namespace in the hash table that contains the
  <prefix, namespace> mappings has the namespaceSeparator character 
  appended to it (it will be nul-terminated if namespaceSeparator == 
  '\0').  

Therefore, it is not possible to simply return a constant pointer because the namespace will not be nul-terminated (except when prefix != NULL and namespaceSeparator == '\0').

The function below returns the length of the uri. I think you don't want to included it as is. Here are two other possible candidates


/* REALLOCs(*out) if *size is not enough to store the URI. Returns XML_ERROR_NO_MEMORY on error, XML_ERROR_NONE otherwise; */
enum XML_Error XML_GetNamespace(XML_Parser parser, const XML_Char *prefix, XML_Char **out, int *size);

/* Copies the URI to `out',  and returns `out' on success. If *size is not enough, store the required size in *size and return 0. */

XML_Char *XML_GetNamespace(XML_Parser parser, const XML_Char *prefix, XML_Char *out, int *size);

This is not a patch. Simply add this to the xmlparse.c:


/* uriLen must not == 0 */
/* pass 0 for prefix to get the current default namespace */

const XML_Char *
XML_GetNamespace(XML_Parser parser, const XML_Char *prefix, int *uriLen)
{
  DTD * const dtd = _dtd; 
  const BINDING *b;

  if (!prefix)
    {
      b = dtd->defaultPrefix.binding;
    }
  else
    {
      PREFIX *p = (PREFIX *)lookup(&dtd->prefixes, prefix, sizeof(PREFIX));

      if (p)
	b = p->binding;
      else
	b = 0;
    }

  
  if (b)
    {
      if (namespaceSeparator)
	*uriLen = b->uriLen - 1;
      else
	*uriLen = b->uriLen;
      return b->uri;
    }
  else
    *uriLen = 0;
  
  return 0;

}


and this  to expat.h:

XMLPARSEAPI(const XML_Char *)
XML_GetNamespace(XML_Parser parser, const XML_Char *prefix, int *uriLen);

BTW, I tried to give expat an illegal URI (h[]p://foo), it didn't complain.


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