                                            W3C Reference Library Release Notes
   W3ClibwwwRELEASE
   
                           LIBRARY 4.1 RELEASE NOTES
                                       
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   The focus for version 4.1 of the W3C Reference Library is to provide a set
   of higher level, application specific APIs for accessing the Web. These APIs
   - called profiles - will help the application, a Web client for example, to
   more easily use the full potential of the application independent Library
   core. Also, the Library contains a significantly better interface for easy
   access to the Web through a large set of functions specialized to perform
   certain Web operations like PUT, POST, DELETE, GETand HEAD.
   
   NOTE_Check out the latest  list of public functions_
   
RELEASE 4.1B4 AUGUST 20 1996

   HTTP version 1.1 allows for effective use of persistent connections.
   However, in orderto make this work, a client application must be capable of
   recovering from a closed connection between sent requests. The beta 4
   version of libwww supports automatic connection recovery and provides the
   functionality for performing pipelining of requests. That is, there can be
   multiple outstanding requests on the same connection In order to do this,
   the release contains  modifications to the Channel Object, the Host object
   and the Net object.
   
  New Features
  
      Added support for case-insensitive searching for proxies via environment
      variables
      
      Added support for proxy authentication
      
      Changed handling of proxies so that they are not included in the URL
      (invented by Lou M) but is now instead part of the request object. This
      allows for better handling of proxies and also for more freely use of the
      proxy filter as it doesn't affect the other filters anymore.
      
      Added support for TRACE HTTP method in the HTAccess module.
      
      Updated News DLL and incorporated News patches from _Maciej Puzio_
      
      HT_PERSISTENTis now obsolete and should be replaced by HT_PENDING
      
      The HTChannelModeenumeration describing the flow of a channel has been
      replaced by HTTransportModeas it is now a part of the transport object
      and not the channel object
      
      HTNet_idle()has been removed and replaced by HTNet_isIdle(). The function
      returns YES if there are no pending requests in libwww at all.
      
      Add support for checking public information about a host and use this
      information when issuing a PUT, for example. Also add check for host
      element in HTAccess when doing PUT. We may have public information
      available
      
      Changed the return codes defined in HTUtils to reflect the values of the
      HTTP spec.
      
      Added support for 305 Use Proxyredirections
      
      Updated HTDir module to better use the fact that we know that an entry is
      a directory or not. Now it appends a '/' to the URL if it is a directory.
      That way we often avoid a redirection.
      
      Removed WWWRules as interface and merged it with the WWWApp interface.
      The reason was that the two were highly alike and depended on each other
      
  Bug Fixes
  
      Fixed problem with uploading directory listing using chunked encoding
      
      Fixed autoconf to handle WAIS and updated the HTWAIS.c module
      
      Fixed race problem in PUT on alphas
      
      Tested reentrant version of libwww (uses _REENTRANTdefine)
      
      Fixed problem in file name conversion from URL to local format on Windows
      
RELEASE 4.1B3 JULY 20 1996

   This release contains a TCL add-on to the Robotexample application and a
   Deja GNU Test suite for the Library. Also, it support HTTP/1.1 including
   persistent connections, two-way PUT, and the hostheader. There is also a
   sample PEP implementation, that although incomplete can give an idea of
   where we're headed using PEP.
   
   The file access module now does content negotiation by default. This means
   that all local file access (including from client applications) _do_ content
   negotiation when accessing local files. Content negotiation can be turned
   off by setting a flag in the request object.
   
   A main difference in beta 3 is that we now have a set of "application
   profiles" that helps the application to initialize libwww core to work as a
   typical client, robot or other type of application. This should replace the
   huge initialization procedure seen in previous versions. This is in fact a
   result of the core being so flexible - it is inly a framework for accessing
   the Web. The application must initialize all the functionality at run-time.
   You can see the various profile functions in the WWWInit interface.
   
   The second main difference is that the _BEFORE_ and _AFTER_ filters have
   been more explicit than before. The HTLoadStartand HTLoadTerminatefunctions
   actually covered many typical _BEFORE_ and _AFTER_ filter functions like
   looking for proxies, searching the cache, looking for rule file matching,
   and logging etc.
   
   However, two functions were not covered by this: _redirection_ and
   _authentication_. That is why the application in previous version had to
   supply this functionality. However, in beta 3 we have split up the
   HTLoadStartand HTLoadTermintefunctions into a set of filters which each
   perform only a single function, for example looking for proxies. The split
   has two functions: first it shows how you can use filtes to add new
   functionality to the Library and second it can be used by more types of
   applications. A result of the new filters is that we also have default
   redirection and authentication filters so you don't have to provide this
   anymore.
   
   The filters are set up as part of the profiles so you will normally not have
   to register them individually.
   
  New features and Changes
  
      Introduced HTUserprofile class to handle host and user specific
      information
      
      Added Chunked decoding and encoding module
      
      A host name is not expanded to a _fqdn_ name as it is not reliable
      enough. Now we just keep it as is, that is we don't expand _www_ to
      _www.w3.org_, for example.
      
      Updated HTML parser to support BASEtag and LINKtag
      
      Added new access methods to the HTAccess module. It is now part of the
      WWWApp interface
      
      Updated the Icon module and added icons to the distribution file
      
      Added a Stream to Chunk converter for easier conversion of streams into
      dynamic memory buffers
      
      Introduced HTLib as a new core module. It contains generic information
      about the core which used to be in the HTAccess module.
      
      Added support for HTTP/1.1. Most of the HTTP/1.1 specification is now in
      place, we still need some headers and some features but this version can
      be considered to be compliant.
      
      Added suport for proxy authentication as specified by HTTP/1.1
      
      Added support for case-insensitive searching for proxies via environment
      variables
      
      Changed handling of proxies so that they are not included in the URL but
      is now instead part of the request object. This allows for better
      handling of proxies and also for more freely use of the proxy filter as
      it doesn't affect the other filters anymore.
      
  Bug Fixes
  
      Fixed problem with uploading directory listing using chunked encoding
      
      Fixed problem in the rule file parser. It didn't parse the last line of
      the config file
      
      Fixed autoconf to handle WAIS and updated the HTWAIS.c module
      
      Fixed race problem in PUT on alphas which caused the PUT operation to
      hang under certain circumstances
      
RELEASE 4.1B1 MAY 20 1996

  New Features
  
      Introduced GNU autoconf configure script for compiling on Unix platforms
      instead of the old BUILD script. This should make it a lot easier to
      compile on Unix as we get all the advantages of GNU autoconf.
      
      Introduction of the HTUserprofile Class which keeps track of a "user"
      known to the Library
      
      New access authentication interface allowing for dynamic registration of
      new access authentication mechanisms. It provides an easy API for hooking
      in new schemes.
      
      Improved handling of trace messages which allows for easy redirection of
      trace messages
      
      Support for registration of content coders/decoders and content transfer
      encoders/decoders. This is done the same way as for media types by
      registering a set of streams that can handle the various encodings.
      
      Support for _chunked_ decoding
      
      Introduction of the HTHost Class which keeps track of information about
      remote hosts
      
      The DNS Class has been simplified to handle DNS queries only. All
      additional information about the remote host is defined by the HThost
      Class.
      
      We have a new HTEvent module which allows for dynamic registration of an
      event manager. This will make it much easier to use external event
      managers together with libwww. If you wish to continue to use the event
      loop from HTEvntrg, you must register it explicitly with HTEventrgInit.
      This call is demonstrated in HTBrowse.
      
      The HTStream module has been created containing a set of basiv streams
      such as an error stream etc.
      
      Introduction of the HTTransport Class. This allows for dynamic
      registration of transport protocols such as for example the W3Mux
      protocol, TCP access, local file access etc.
      
      All MIME parsing is now done with registered parsers. The HTMIME module
      only unwraps the  MIME header fields and calls the best parser. The
      header parsing origonally done in HTMIME can be found in HTInit.c and is
      registered with HTMIMEInit. This call is demonstrated in HTBrowse.
      
   
   ___________________________________
   
                                         Henrik Frystyk Nielsen, libwww@w3.org,
                                                                               
           @(#) $Id: ReleaseNotes.html,v 1.36 1996/08/21 14:13:11 frystyk Exp $
                                                                               
   
