Webware / WebKit / Docs / RelNotes-0.9.phtml

<% header(name + ' 0.9 Release Notes') %>

<p><% name %> version 0.9 released on 11/13/05</p>

<a name="Introduction"></a><h2>Introduction</h2>
<p>It has taken much longer than usual to finish this release,
and it is impossible to track and list every change.
So the following will mention only a few of the many changes,
improvements and bugfixes that have been made.</p>

<a name="NewFeatures"></a><h2>New Features</h2>
  <li>Added If-Modified-Since support to HTTPServlet. A Servlet can provide a
  lastModified() method which returns the modification time of the data.
  This has been integrated into the UnknownFileType servlet for handling
  static files.</li>
  <li>The <span class="filename">AppServer</span> script detects
  <code>-u</code> (unbuffered output) and <code>-O</code> (optimize)
  parameters and passes them to Python. These parameters must precede
  any other parameters. Other parameters will be passed to
  <code>ThreadedAppServer</code> normally.</li>
  <li>Configuration parameters can now be overridden with the command line.
  You can run <span class="filename">AppServer</span> with switches in the
  form <code>ClassName.SettingName=value</code>, e.g.
  <li>Configuration files can be written as Python modules instead of as
  Python dictionaries. Any global variables in the module are equivalent
  to top-level keys in the configuration dictionary.</li>
  <li><span class="filename"></span> accepts a new option
  <code>-d</code> allowing to point the default context to a location not
  inside the working directory, so you can keep your code completely separate
  from the working directory. It also accepts <code>-l</code> options to
  add multiple application library dirs to the Python path, and options to
  set the ownership of the working directory files. To see all options,
  run the command without any parameters.</li>
  <li>Added <code>EnterDebuggerOnException</code> option to
  <span class="filename">Application.config</span>. If True, and if the
  AppServer is running from an interactive terminal, an uncaught exception
  will cause the AppServer to enter the debugger, allowing the developer to
  call functions, investigate variables, etc. See Python debugger (pdb) docs
  for more information. You will certainly want to turn this off when
  deploying the site. Defaults to False (off).</li>
  <li>The AppServer now includes an experimental built-in HTTP web server.
  See the <a href="InstallGuide.html">InstallGuide</a> for more details.</li>
  <li>Added new <span class="filename">Application.config</span> option
  <code>UseCookieSessions</code> that defaults to True. If set to False,
  then a session cookie will never be sent in the response. Use this along
  with <code>UseAutomaticPathSessions</code> to <em>only</em> use path
  sessions and never use cookie sessions.</li>
  <li>Added <code>HTTPRequest.setSessionId()</code> method which allows
  the use of session IDs that are sent via means other than cookies or
  URL parameters (an example would be via an XML-RPC parameter).
  See the docstring for more details.</li>
  <li>Added <code>DebugAppServer</code>, a single-threaded app server
  that makes it possible to debug servlets using a standard Python
  debugger. Tested on Windows only, using both PythonWin and JEdit with
  the JPyDbg plugin. See
  <span class="filename">WebKit/</span> for details.</li>
  <li>New debugging feature: by turning on the configuration variable
  <code>IncludeEditLink</code> in
  <span class="filename">Application.config</span>, an <a href="#">[edit]</a>
  link will be put next to each line in tracebacks. That link will point
  to a file of type <tt>application/x-webkit-edit-file</tt>, which you
  should configure your browser to run with
  <span class="filename">Webware/bin/</span>.
  If you configure <span class="filename"></span> correctly,
  then it will automatically open the respective Python module with your
  favorite Python editor and put the cursor on the erroneous line.</li>

<a name="Improvements"></a><h2>Improvements and Refinements</h2>
  <li><code>WebKit.Object</code> now inherits Python's object.
  This affects all other classes for which Super() should now work.</li>
  <li>Unknown file types (those for whom <code>mimetypes.guess_type()</code>
  cannot return something meaningful) are now served up with a mime type of
  <tt>application/octet-stream</tt> instead of <tt>text/html</tt>.</li>
  <li>Fixed incompatibility between the NT Service code and win32all 163.</li>
  <li>AutoReload no longer catches servlet updates (since servlets can be
  reloaded without restarting the entire server anyway).</li>
  <li><code>XMLRPCServlet</code> now allows <code>xmlrpclib.Fault</code>
  exceptions to be passed through unmolested.</li>
  <li><code>Page</code> has been refactored into <code>HTTPContent</code>
  and <code>Page</code>. <code>HTTPContent</code> can be used as a base
  class for servlets which generate non-HTML content. As <code>Page</code>
  inherits from <code>HTTPContent</code> (which inherits from
  <code>HTTPServlet</code>), <code>Page</code> still contains all the
  methods it previously did, and this change should not require any changes
  to end-user code.</li>
  <li><code>XMLRPCServlets</code> are now allowed to return None as part of
  their marshaled response. This improves usability in an all-Python
  environment at the possible cost of compatibility problems
  with non-Python clients. To revert to the old behavior, where an
  attempt to respond with <code>None</code> caused an exception, add
  <code>allow_none = False</code> to your <code>XMLRPCServlet</code>-derived
  servlets at class level (adding <code>self.allow_none = False</code>
  in the <code>__init__</code> should also work).</li>
  <li>Fixed problem where SessionDynamicStore would unpickle the same object
  <li>Added <code>transaction()</code> method to <code>RPCServlet</code>
  so that there's a way for a method to get the transaction object if
  <li><p>Previously, attempting to start an already-running AppServer
  would fail when it couldn't grab the socket to listen on, but it would
  have already overwritten the pid file.</p>
  <p>Now pid file handling is much improved:</p>
    <li>The AppServer will refuse to start if it detects that the pid file
    exists and the process is still running.</li>
    <li>A stale pid file left over from a crash or forcible termination
    will be detected and removed.</li>
    <li>You can override the path of the pid file using the
    <code>PidFile</code> setting in
    <span class="filename">AppServer.config</span>. By default,
    the pid is written to <span class="filename">appserverpid.txt</span>
    in the working directory (or WebKit path if you're not using a working
    <li>You can disable the use of the pid file by setting it to
    <code>None</code> in <span class="filename">AppServer.config</span>.
    This seems to be a good idea on Windows because Windows often
    reuses the same pid right away, so if the appserver crashes, and it
    tries to restart and it happens to reuse the same pid, the restart
    will fail.</li>
  <li><p>The shutdown handling has been improved. Sending <tt>SIGHUP</tt>
  now results in exiting with exit code 3 which is used for reloading via
  the AppServer script.</p></li>
  <li>The <span class="filename"></span> file has been improved
  and supports several new command line options.</li>
  <li>The <span class="filename">AppServer</span> and
  <span class="filename"></span> don't need to be called from
  the working directory any more, and the location of the working
  directory is assumed to be the location of the script,
  and not hard coded in <span class="filename"></span>.
  You can still change this at the top of the script, however.</li>
  <li>The Unix start script <span class="filename">WebKit/webkit</span>
  which was based on RedHat Linux has been replaced by a folder
  <span class="filename">WebKit/StartScripts</span> with a bunch of
  start sripts for various flavors of Unix, including a "generic" version.
  The installer will try to copy the most appropriate start script
  to <span class="filename">WebKit/webkit</span>. If instead of copying,
  you create a link to the start script in your working directory, it will
  find out the location of the working directory automatically.</li>
  <li>The Examples and Admin sections have been improved and adapted
  to the API changes.</li>

<a name="Changes"></a><h2>Changes</h2>
  <li>The <code>Port</code> setting in
  <span class="filename">AppServer.config</span> has been deprecated in
  favor of the new <code>AdapterPort</code> setting. The <code>Port</code>
  setting in your config file will still be honored, but you are encouraged
  to update your <span class="filename">AppServer.config</span> as the
  <code>Port</code> setting will be removed in the future.</li>
  <li>The scripts <span class="filename"></span>
  in the WebKit directory and <span class="filename">NTService</span> created
  by <span class="filename"></span> were both renamed to
  <span class="filename"></span>.</li>
  <li>Removed the <span class="filename">Application.config</span> setting
  <code>OldStyleActions</code> and re-implemented support of the
  <code>methodNameForAction()</code> transformation. Note that "old style"
  actions took an additional <code>transaction</code> parameter, but
  otherwise the action handling is now downward compatible.</li>
  <li>In <code>WebKit.Page</code> resp. <code>WebKit.HTTPContent</code>,
  removed both the internal method <code>_actionSet()</code> and the internal
  dictionary <code>_actionDict</code> which cached the list of actions
  for the servlet. This was redundant code, and its removal allows a servlet
  to use dynamic actions (i.e. to make the action list dependent on the
  permissions of the logged-in user).</li>
  <li><p>The semantics for the awake-respond-sleep cycle have changed so
  that Servlet.sleep() is <em>always</em> called, even when an unhandled
  exception occurs in Servlet.awake() or Servlet.respond().
  Servlet.sleep() is called even when Page.endResponse() or
  Page.sendRedirectAndEnd() have been called to end servlet
  processing prematurely.  This behavior differs from previous
  versions, in which sleep() was called only if awake() succeeded.</p>
  <p>The intent of this change is to guarantee servlets the chance to free
  resources, without having to be prepared to catch all possible exceptions
  within awake() to do so.</p>
  <p>The programmer should ensure that sleep does not attempt to free
  resources which were never allocated, as sleep() may be called even when
  awake() did not succeed.</p>
  <pre class="py">
    def awake(...):
      initialize resource A
      initialize resource B

    def sleep(...):
      if resource B was initialized:
        finalize resource B
      if resource A was initialized:
        finalize resource A
  <li>The PythonServletFactory had only served <tt>.py</tt> source files
  so far. Now it will serve <tt>.pyc</tt> and <tt>.pyo</tt> files as well.
  For the default configuration, this makes no difference, since <tt>.pyc</tt>
  and <tt>.pyo</tt> are in both settings <tt>ExtensionsToIgnore</tt> and
  <tt>FilesToHide</tt>, so they will not be served anyway. By removing
  <tt>.pyc</tt> and <tt>.pyo</tt> away from these settings, you can now
  install servlets without their source code. This will be a little bit
  more performant in the production environment, but most of all it will
  prevent customers and administrators from messing around with the source
  code and give a certain level of protection as closed source (this feature
  had been requested several times). Before, <tt>.pyc</tt> and <tt>.pyo</tt>
  had not been executed, but delivered as unknown file types which does not
  make much sense and can be a security problem, for instance when database
  passwords and other information is stored in the servlets. By using
  <tt>ExtensionCascadeOrder</tt>, you can also determine a priority, such as
  <tt>.py</tt> first (if available), then <tt>.pyo</tt>, then <tt>.pyc</tt>.
  However, the standard configuration still ignores/hides <tt>.pyc</tt> and
  <tt>.pyo</tt> files completely and looks only at the <tt>.py</tt> file,
  so you still have to change the settings explicitely in
  <span class="filename">AppServer.config</span> if you want to use this.
  Also, note that <tt>.pyc</tt> and <tt>.pyo</tt> files can be decompiled
  so this will be no real unsurmountable protection.</li>

<a name="Bugfixes"></a><h2>Bugfixes</h2>
  <li>Fixed handling of expired sessions. Previously, if you tried to access
  an expired session before the session sweeper thread had cleaned it out,
  you'd get that expired session for one request, but on the second request
  you'd get a new session. Now it correctly returns a new empty session with
  a new session ID on the first request after expiration.</li>
  <li>Fixed a bug in <tt>mod_webkit</tt> for Apache&nbsp;2.X that might
  have been causing <tt>mod_webkit</tt> to retry connections to the app
  server unnecessarily in some cases. (This does not apply to the
  Apache&nbsp;1.3 version of <tt>mod_webkit</tt>.)</li>

<% footer() %>