WebStack

README.txt

674:ff6bf5a5575e
2007-09-28 paulb [project @ 2007-09-28 23:04:23 by paulb] Updated release notes.
     1 Introduction
     2 ------------
     3 
     4 WebStack is a package which provides a common API for Python Web
     5 applications, regardless of the underlying server or framework environment.
     6 It should be possible with WebStack to design and implement an application,
     7 to choose a deployment environment, and then to be able to deploy the
     8 application in a different environment later on without having to go back
     9 and rewrite substantial parts of the application.
    10 
    11 Quick Start
    12 -----------
    13 
    14 Try running the demo:
    15 
    16 python tools/demo.py
    17 
    18 An introductory guide to creating applications can be found in the docs
    19 directory - see docs/index.html for the start page.
    20 
    21 Contact, Copyright and Licence Information
    22 ------------------------------------------
    23 
    24 The current Web page for WebStack at the time of release is:
    25 
    26 http://www.boddie.org.uk/python/WebStack.html
    27 
    28 Copyright and licence information can be found in the docs directory - see
    29 docs/COPYING.txt, docs/LICENCE.txt and docs/LICENCE-PyServlet.txt for more
    30 information.
    31 
    32 Framework Support
    33 -----------------
    34 
    35 See the docs/supported-frameworks.html document for more information.
    36 
    37 New in WebStack 1.2.6 (Changes since WebStack 1.2.5)
    38 ----------------------------------------------------
    39 
    40   * Improved support for Jython on Ubuntu Feisty (7.04), adding python.path
    41     and python.cachedir settings which respectively avoid issues with missing
    42     libraries (due to the separation of libraries in the Ubuntu package) and
    43     with failed imports (due to a read-only class cache directory).
    44   * Added more Jython-related documentation as suggested by Kevin Glynn.
    45   * Added missing request headers for CGI/WSGI environment variables.
    46   * Fixed Webware support to work with Webware 0.9.4.
    47 
    48 New in WebStack 1.2.5 (Changes since WebStack 1.2.4)
    49 ----------------------------------------------------
    50 
    51   * Fixed mod_python status codes using a solution proposed by John Krukoff.
    52   * Fixed a Twisted deprecation warning when accessing port numbers, thanks to
    53     John Krukoff.
    54   * Added Ubuntu Feisty (7.04) package support.
    55   * Tidied up the documentation HTML.
    56 
    57 New in WebStack 1.2.4 (Changes since WebStack 1.2.3)
    58 ----------------------------------------------------
    59 
    60   * Made a SessionDirectoryRepository which uses directories for data produced
    61     by the shelve module, rather than attempting to manipulate files produced
    62     by the shelve module, since the details of such files may differ between
    63     environments: a situation noticed by John Krukoff in an environment
    64     without the bsddb module installed.
    65 
    66 New in WebStack 1.2.3 (Changes since WebStack 1.2.2)
    67 ----------------------------------------------------
    68 
    69   * Fixed inadvertent OpenSSL dependency, noticed by John Krukoff.
    70 
    71 New in WebStack 1.2.2 (Changes since WebStack 1.2.1)
    72 ----------------------------------------------------
    73 
    74   * Added an EncodingSelector class for the setting of default encodings on
    75     transactions.
    76   * Added some documentation about path processing strategies.
    77   * Added a secure variant of the BaseHTTPServer provided in the adapter for
    78     BaseHTTPRequestHandler.
    79 
    80 New in WebStack 1.2.1 (Changes since WebStack 1.2)
    81 --------------------------------------------------
    82 
    83   * Fixed mod_python get_content_type method.
    84   * Fixed LoginResource form field processing; changed the field type to
    85     password.
    86   * Exposed LoginResource and LoginRedirectResource page contents as
    87     attributes.
    88   * Added documentation about extending LoginRedirectResource and using
    89     PathSelector to remember an application's root path.
    90   * Changed handle_errors to 1 throughout the examples.
    91 
    92 New in WebStack 1.2 (Changes since WebStack 1.1.2)
    93 --------------------------------------------------
    94 
    95   * Added support for Django.
    96   * Fixed documentation about the representation of file upload fields.
    97   * Changed mod_python, Java Servlet and Webware (> 0.8.1) deployment to use a
    98     deploy function instead of more complicated configuration mechanisms.
    99   * Improved mod_python deployment documentation and tools so that cleaner
   100     application paths/URLs can now be used.
   101   * Moved user and path_info default definitions into WebStack.Generic as
   102     class attributes.
   103   * Fixed encoding usage issues with path fields when using get_fields in a
   104     Zope environment.
   105   * Added a FileResource class to WebStack.Resources.Static.
   106   * Made DirectoryRepository convert filenames to Unicode in all cases.
   107   * Renamed the Apache and Java Servlet tools, making them scripts which are
   108     installed by setup.py.
   109   * Fixed CGI content charsets and languages support.
   110   * Fixed CGI cookie output.
   111   * Added URL overriding in the LoginRedirectResource.
   112   * Exposed a get_target function from WebStack.Resources.Login in order to
   113     better support alternative login resources.
   114   * Added improved error reporting for BaseHTTPRequestHandler, CGI, Django and
   115     WSGI.
   116   * Added a traverse_path method to the Transaction class.
   117   * Made a path_encoding alias for urlencoding in the initialisation of
   118     WebStack.Resources.ResourceMap objects.
   119   * Added a Selectors module to WebStack.Resources in order to support common
   120     resource selection patterns.
   121 
   122 New in WebStack 1.1.2 (Changes since WebStack 1.1.1)
   123 ----------------------------------------------------
   124 
   125   * Fixed missing import in WebStack.Repositories.Directory.
   126 
   127 New in WebStack 1.1.1 (Changes since WebStack 1.1)
   128 --------------------------------------------------
   129 
   130   * Fixed update_path to handle the root path properly.
   131 
   132 New in WebStack 1.1 (Changes since WebStack 1.0)
   133 ------------------------------------------------
   134 
   135   * Added a Repositories package to provide session-like support for
   136     different kinds of storage.
   137   * Added an explicit filesystem encoding to the Calendar example and adopted
   138     the DirectoryRepository from the Repositories package.
   139   * Added get_path_without_info, update_path and redirect methods to the
   140     Transaction class.
   141   * Added get_attributes (attribute support) to the Transaction class.
   142   * Added a values method to Helpers.Session.Wrapper.
   143   * Fixed get_processed_virtual_path_info (to match from right to left).
   144   * Improved/fixed exception handling in the adapters so that transactions are
   145     committed as the final act of an adapter experiencing an unhandled
   146     exception. This should result in session stores being closed properly.
   147   * Changed the Helpers.Session.SessionStore to use DirectoryRepository.
   148   * Made the "not found" behaviour of DirectoryResource more configurable.
   149   * Added documentation for MapResource and DirectoryResource.
   150   * Fixed the distribution names in the Ubuntu changelog.
   151 
   152 New in WebStack 1.0 (Changes since WebStack 0.10)
   153 -------------------------------------------------
   154 
   155   * Changed the behaviour of get_path, get_path_without_query, get_path_info,
   156     get_virtual_path_info, get_processed_virtual_path_info and
   157     get_fields_from_path to return Unicode data decoded using the optional
   158     encoding parameter or a common default encoding.
   159   * Fixed file upload values so that FileContent objects are returned for such
   160     fields in get_fields_from_body and get_fields.
   161     (Warning! Except for Twisted!)
   162   * Fixed the JavaServlet support so that streams and file content are
   163     obtained as "almost" plain strings.
   164   * Updated/fixed LoginResource and LoginRedirectResource to use the updated
   165     path API and to handle special characters properly.
   166   * Added convenience methods to Transaction for the decoding and encoding of
   167     path values (to and from Unicode objects) - see the decode_path and
   168     encode_path methods.
   169   * Added the notion of processed virtual path info - the part of the original
   170     path info not represented in the current virtual path info.
   171   * Added "pass through" behaviour to ResourceMap.MapResource (prompted by a
   172     patch from Scott Robinson).
   173   * Fixed ResourceMap.MapResource to handle non-existent resources properly
   174     (where the virtual path info is only one component in length).
   175   * Added Debian package support.
   176   * Added automatic session directory creation for the WebStack sessions
   177     implementation.
   178   * Added support for the repeated retrieval of sessions from the same
   179     WebStack session store, avoiding deadlocks.
   180   * Fixed the calendar example, making it perform a proper function.
   181   * Made the BaseHTTPRequestHandler and Twisted SimpleWithLogin applications
   182     include the Login application, since Konqueror (at least) does not share
   183     cookies across different port numbers on the same host.
   184   * Added the SimpleWithLogin and Login applications to the demonstration.
   185   * Improved the documentation, adding information on request headers, and
   186     describing file upload and session support limitations.
   187   * Improved the AOLserver-related notes for CGI and Webware, adding a patch
   188     for Webware in order to work around AOLserver issues.
   189 
   190 New in WebStack 0.10 (Changes since WebStack 0.9)
   191 -------------------------------------------------
   192 
   193   * Changes to make the tools/demo.py script work on Windows (and other)
   194     platforms (suggested by Jim Madsen).
   195   * Fixed end of header newlines for CGI (suggested by Matt Harrison).
   196   * Minor documentation fixes and improvements, adding information on
   197     AOLserver in the CGI and Webware notes.
   198   * Changed the mod_python server name method to use the server object rather
   199     than the connection object.
   200   * Added a parameter to the ResourceMap.MapResource class to permit automatic
   201     redirects into resource hierarchies when no trailing "/" was given in the
   202     URL; changed the updated virtual path info so that empty values may be set
   203     (the guarantee that "/" will always appear no longer applies).
   204   * Fixed virtual path info retrieval when the value is an empty string.
   205 
   206 New in WebStack 0.9 (Changes since WebStack 0.8)
   207 ------------------------------------------------
   208 
   209   * Standardised error handling in the adapters so that tracebacks can be
   210     suppressed and an internal server error condition raised.
   211   * Added overriding of path info in transactions.
   212   * Added a ResourceMap resource for dispatching to different resources
   213     according to path components.
   214   * Standardised deployment for some frameworks (see docs/deploying.html).
   215   * Introductory documentation in XHTML format.
   216   * Added server name and port methods to the transaction.
   217   * Added a simple demonstration application, incorporating many of the
   218     examples and launched under a single script.
   219   * Fixed mod_python native sessions.
   220   * Fixed Zope request stream access.
   221   * WebStack is now licensed under the LGPL - see docs/COPYING.txt for
   222     details.
   223 
   224 New in WebStack 0.8 (Changes since WebStack 0.7)
   225 ------------------------------------------------
   226 
   227   * Added a standard exception, EndOfResponse, which can be used to
   228     immediately stop the processing/production of a response; this is useful
   229     when resources need to issue a redirect without unnecessary content being
   230     generated, for example.
   231   * Fixed path information for Zope.
   232   * Added WSGI support.
   233   * Verified Twisted 1.3.0 support with Python 2.3.3.
   234 
   235 New in WebStack 0.7 (Changes since WebStack 0.6)
   236 ------------------------------------------------
   237 
   238   * Fixed path information semantics.
   239   * Fixed file upload semantics.
   240   * Fixed content type handling for Unicode output and for interpreting
   241     request body fields/parameters (although some improvement remains).
   242   * Added a method to discover the chosen response stream encoding.
   243   * Fixed field/parameter retrieval so that path and body fields are distinct,
   244     regardless of the framework employed.
   245   * Added a method to get a combination of path and body fields (suggested by
   246     Jacob Smullyan).
   247   * Introduced Zope 2 support.
   248   * Improved Jython/Java Servlet API support (although a special PyServlet
   249     class must now be used, and certain libraries must be deployed with
   250     applications).
   251   * Introduced authentication/authorisation support for Jython/Java Servlet
   252     API.
   253   * Session support has been added (except for Webware 0.8.1).
   254   * Alternative cookie support for mod_python has been added.
   255   * Cookie support now supports encoded Unicode sequences for names and
   256     values.
   257 
   258 New in WebStack 0.6 (Changes since WebStack 0.5)
   259 ------------------------------------------------
   260 
   261   * Introduced Jython/Java Servlet API support.
   262   * Minor fixes to example applications and to BaseHTTPRequestHandler.
   263 
   264 New in WebStack 0.5 (Changes since WebStack 0.4)
   265 ------------------------------------------------
   266 
   267   * Changed request body fields/parameters so that they are now represented
   268     using Unicode objects rather than plain strings.
   269   * Introduced better support for Unicode in response streams.
   270 
   271 New in WebStack 0.4 (Changes since WebStack 0.3)
   272 ------------------------------------------------
   273 
   274   * Added application definition of user identity, permitting alternative
   275     authentication mechanisms.
   276   * Improved BaseHTTPRequestHandler and mod_python reliability around fields
   277     from request bodies.
   278   * Provided stream and environment parameterisation in the CGI adapter.
   279   * Added LoginRedirect and Login examples.
   280   * Added get_path_without_query and fixed get_path behaviour.
   281 
   282 New in WebStack 0.3 (Changes since WebStack 0.2)
   283 ------------------------------------------------
   284 
   285   * Added better header support for Webware (suggested by Ian Bicking).
   286   * Introduced CGI and Java Servlet support (the latter is currently
   287     broken/unfinished).
   288   * Introduced support for cookies.
   289 
   290 Future Work
   291 -----------
   292 
   293 (Essential)
   294 
   295 Twisted 1.3.0 does not provide file upload metadata, and Twisted Web 0.5.0
   296 also seems to be missing this functionality. It isn't obvious whether Twisted
   297 Web2 will just copy its predecessors and provide a similarly limited API.
   298 Perhaps the Twisted support needs to resemble the CGI support much more when
   299 handling fields.
   300 
   301 JythonServlet libraries need to be configured using sys.add_package when
   302 these do not feature in the compiled-in list. Adding such configuration to
   303 the handler may be most appropriate (since the web.xml file can be too
   304 arcane), but this needs testing.
   305 
   306 The algorithm employed in the WebStack.Helpers.Auth.get_token function
   307 should be reviewed and improved for better security.
   308 
   309 (Important)
   310 
   311 Field access needs testing, especially for anything using the
   312 cgi.FieldStorage class, and the way file uploads are exposed should be
   313 reviewed (currently the meta-data is not exposed). The acquisition of fields
   314 from specific sources should be tested with different request methods - some
   315 frameworks provide path fields in the body fields dictionary, others (eg.
   316 Zope) change the fields exposed depending on request method.
   317 
   318 Interpretation of path field encodings needs to be verified. Currently,
   319 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
   320 ISO-8859-1, but it might be the case that some such fields might be
   321 submitted as UTF-8. The decode_path method on Transaction does do much of the
   322 work that is likely to be required, however. Still, a good policy for decoding
   323 path fields, reducing the number of times one might specify the encoding in
   324 various method calls, may be important.
   325 
   326 An interesting test of encodings is to introduce things like the following to
   327 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
   328 This should produce the following decoded result: %F0?æ=ø&%F0=ø
   329 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
   330 
   331 Cookie objects need defining strictly, especially since the standard library
   332 Cookie object behaves differently to mod_python (and possibly Webware)
   333 Cookie objects. Moreover, the set_cookie_value method needs to provide
   334 access to the usual cookie parameters as supported by the frameworks. The
   335 standard library Cookie module has issues with Unicode cookie names (and
   336 possibly values) - this is worked around, but it would be best to resolve
   337 this comprehensively.
   338 
   339 UTF-16 (and possibly other encodings) causes problems with HTML form data
   340 sent in POST requests using the application/x-www-form-urlencoded content
   341 type.  This should be reviewed at a later date when proper standardisation
   342 has taken place.
   343 
   344 Session support, especially through WebStack.Helpers.Session, should be
   345 reviewed and be made compatible with non-cookie mechanisms.
   346 
   347 Locking in the session support and in DirectoryRepository should be improved.
   348 
   349 HeaderValue objects should be employed more extensively. Thus, the header
   350 access methods may need to change their behaviour slightly. The get_headers
   351 method should potentially return a list for each item in the dictionary.
   352 
   353 WSGI support could demand that a special "end of headers" method be
   354 introduced into WebStack, thus making response output more efficient (and
   355 probably also for other frameworks, too).
   356 
   357 Investigate proper support for HEAD, OPTIONS and other request methods.
   358 
   359 Consider packages for different operating systems (other than Debian).
   360 
   361 Investigate cStringIO usage.
   362 
   363 The location of deployed applications in the filesystem should be exposed to
   364 those applications. (This is actually available in the __file__ module
   365 variable.) A resource could be provided to record the "root" path and added to
   366 a resource hierarchy or site map. Note that PathSelector records the "root"
   367 path, although it is not automatically deployed.
   368 
   369 (Completed/rejected)
   370 
   371 Path information should be consistent across all frameworks, and the "path
   372 info" value should be meaningful. (This should now be correct.)
   373 
   374 Investigate the nicer functions in the cgi module, discarding the "magic"
   375 stuff like FieldStorage. (These nicer functions are used by projects like
   376 Twisted - as of 1.3.0 at least - and do not give the necessary information we
   377 require.)
   378 
   379 Release Procedures
   380 ------------------
   381 
   382 Update the WebStack/__init__.py __version__ attribute.
   383 Change the version number and package filename/directory in the documentation.
   384 Change code examples in the documentation if appropriate.
   385 Update the release notes (see above).
   386 Check the setup.py file and ensure that all package directories are mentioned.
   387 Check the release information in the PKG-INFO file and in the package
   388 changelog (and other files).
   389 Tag, export.
   390 Generate the PyServlet classes.
   391 Generate the API documentation.
   392 Remove generated .pyc files: rm `find . -name "*.pyc"`
   393 Archive, upload.
   394 Upload the introductory documentation.
   395 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   396 
   397 Generating the API Documentation
   398 --------------------------------
   399 
   400 In order to prepare the API documentation, it is necessary to generate some
   401 Web pages from the Python source code. For this, the epydoc application must
   402 be available on your system. Then, inside the distribution directory, run the
   403 apidocs.sh tool script as follows:
   404 
   405 ./tools/apidocs.sh
   406 
   407 Some warnings may be generated by the script, but the result should be a new
   408 apidocs directory within the distribution directory.
   409 
   410 Making Packages
   411 ---------------
   412 
   413 To make Debian-based packages:
   414 
   415   1. Create new package directories under packages if necessary.
   416   2. Make a symbolic link in the distribution's root directory to keep the
   417      Debian tools happy. For example:
   418 
   419      ln -s packages/ubuntu-hoary/python2.4-webstack/debian/
   420      ln -s packages/ubuntu-feisty/python-webstack/debian/
   421 
   422   3. Run the package builder:
   423 
   424      dpkg-buildpackage -rfakeroot
   425 
   426   4. Locate and tidy up the packages in the parent directory of the
   427      distribution's root directory.