[Expat-discuss] Please help me about ExternalEntityRefHandler.

[Alexander Lazic]

Hi,

i need some explanation about the 'ExternalEntityRefHandler' ;-)

I need to check the definition in the DTD with the data which i get.

I'm not shure that expat is the right tool for that, can he parse DTD?

1.) what can the 'context' be?
2.) and which parser does i need the 'XML_ParserCreate' or
    'XML_ExternalEntityParserCreate'?

typedef int
(*XML_ExternalEntityRefHandler)(XML_Parser p,
                                const XML_Char *context,
                                const XML_Char *base,
                                const XML_Char *systemId,
                                const XML_Char *publicId);

The doc said:

.
.

>Second, instead of having userData as its first argument, it receives
>the parser that encountered the entity reference.

Therefore i need the 'XML_ExternalEntityParserCreate' or?

>This, along with the context parameter, may be used as arguments to a
>call to  XML_ExternalEntityParserCreate. Using the returned parser, the
>body of the external entity can be recursively parsed.

I don't understand this right i think :-(

Test.xml:

<!DOCTYPE ZMR SYSTEM "zmr.dtd">
 <ZMR>

 <Action>MYA</Action>

 <Person>

  <IdentMerkmale>
   <Familienname>Mustinger</Familienname>
   <Vorname>Maximilian</Vorname>
   <Staatsangehoerigkeit>Oesterr</Staatsangehoerigkeit>
   <Geburtsdatum>01.01.2002</Geburtsdatum>
   <Geburtsort>Port</Geburtsort>
  </IdentMerkmale>
  <Geschlecht>M</Geschlecht>
  <Bundesland_der_Geburt>Blah</Bundesland_der_Geburt>
  <Geburtsstaat>OEst</Geburtsstaat>
  <Person_Grund_Beginn_Code>GEB</Person_Grund_Beginn_Code>
  <Person_Grund_Beginn>Geburt</Person_Grund_Beginn>
  <Person_Beschreibung_Beginn>Neujahrsbaby</Person_Beschreibung_Beginn>
 </Person>
</ZMR>

Are the context ZMT or ACTION or PERSON ...?
And when should be called the ExternalParser bevor or after start?

Here the c-snipped:

  FILE *infile=fopen(*++argv,"r");
  outfile=fopen(*++argv,"w");

  XML_Parser parser = XML_ParserCreate("UTF-8");
    /* When should i use this? */
  XML_Parser extparser = XML_ExternalEntityParserCreate(parser,"ZMR","UTF-8");

  XML_SetElementHandler(parser, startElement, endElement);
  XML_SetExternalEntityRefHandler(parser,externalEntityRefHandler); 
  XML_SetParamEntityParsing(parser,XML_PARAM_ENTITY_PARSING_ALWAYS);
  XML_SetCharacterDataHandler(parser,characterDataHandler);

and the function 'externalEntityRefHandler':

int
externalEntityRefHandler(XML_Parser p, const XML_Char *context, const
XML_Char *base, const XML_Char *systemId, const XML_Char *publicId){

  fprintf(outfile,"context :%s: base :%s: systemid :%s: pubid :%s:\n",
                          context,base,systemId,publicId);
  return 0;
}
			     
Please can anybody explain me Step by step how can i use this feature
from expat, a link whith a example?

Thanx

al ;-)