W3C Sample Code Library libwww MIME Headers

# MIME Headers

    /*
    **	(c) COPYRIGHT MIT 1995.
    **	Please first read the full copyright statement in the file COPYRIGH.
    */

This module handles lists of callback functions for generating and parsing protocol headers. This works exactly like the lists in HTFormat.

This module is implemented by HTHeader.c, and it is a part of the W3C Sample Code Library.

    #ifndef HTHEADER_H
    #define HTHEADER_H

    #include "HTResponse.h"
    #include "HTStream.h"

We have two call back functions: the first is for generating headers. This needs a stream to put down the extra headers. This one is defined in the Request Manager. The other one is for parsing. This needs the string to parse.

    typedef int HTParserCallback (HTRequest * request, HTResponse * response,
                                  char * token, char * value);

## Header Parser Management

Header Parsers can be registered to handle any header. The standard set of HTTP/1.1 MIME parsers is registered by HTMIMEInit in the HTInit module. The HTParserCallbacks are called by the HTMIME module.

HTParserCallbacks may be registered for known MIME headers (HTParser_*), or for regular expressions (HTRegexParser_*). To data the regex support is limited to the use of '*' for a wild card.

## Header Generator Management

Header Generators can be use to add additional information to aprotocol request. They will all be called.

    extern BOOL HTGenerator_add (HTList * gens, HTPostCallback * callback);
    extern BOOL HTGenerator_delete (HTList * gens, HTPostCallback * callback);
    extern BOOL HTGenerator_deleteAll (HTList * gens);

## Global List Of Parsers and Generators

As in HTFormat module you can register a list globally or locally as you like. The local registrations is managed by Request Manager

### Header Parsers

    #define MIME_HASH_SIZE  HT_L_HASH_SIZE

    extern void HTHeader_setMIMEParseSet (HTMIMEParseSet * list);
    extern HTMIMEParseSet * HTHeader_MIMEParseSet (void);
    extern BOOL HTHeader_addParser (const char * token, BOOL case_sensitive,
    				HTParserCallback * callback);
    extern BOOL HTHeader_addRegexParser (const char * token, BOOL case_sensitive,
    				HTParserCallback * callback);
    extern BOOL HTHeader_deleteParser (const char * token);

### Header Generation

    extern void HTHeader_setGenerator (HTList * list);
    extern BOOL HTHeader_addGenerator (HTPostCallback * callback);
    extern BOOL HTHeader_deleteGenerator (HTPostCallback * callback);
    extern HTList * HTHeader_generator (void);

### Delete all Global Lists

    extern void HTHeader_deleteAll (void);

    #endif /* HTHEADER_H */