WebStack

README.txt

447:c3f840373794
2005-08-25 paulb [project @ 2005-08-25 13:40:37 by paulb] Updated release notes (adding virtual path API changes).
     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 Currently, BaseHTTPRequestHandler (via BaseHTTPServer in the standard
    36 library), CGI, Jython/Java Servlet API, mod_python, Twisted, Webware, WSGI
    37 and Zope 2 are supported. Each framework has its own set of strengths and
    38 weaknesses, but the idea is that deployment concerns can be considered
    39 separately from the implementation of application functionality. Consult the
    40 NOTES.txt files in each framework's subdirectory of the docs directory for
    41 some notes on how applications may be run in each environment.
    42 
    43 Tested Frameworks           Release Information
    44 -----------------           -------------------
    45 
    46 BaseHTTPRequestHandler      Python 2.2.2, Python 2.3.3, Python 2.4.1
    47 CGI                         Apache 2.0.44, Apache 2.0.53, AOLserver 4.0.10, lighttpd 1.3.15
    48 Jython/Java Servlet API     Jython 2.1, Java JDK 1.3.1_02, Tomcat 4.1.31 (Servlet 2.3)
    49 mod_python                  3.0.3 (3.1.3 for framework cookie and session support)
    50 Twisted                     1.0.5, 1.3.0
    51 Webware                     0.8.1, CVS (2004-02-06), 0.9b2
    52 WSGI                        run_with_cgi (PEP 333)
    53 Zope                        2.7.2-0, 2.8.0-final
    54 
    55 New in WebStack 1.0 (Changes since WebStack 0.10)
    56 -------------------------------------------------
    57 
    58 Changed the behaviour of get_path, get_path_without_query, get_path_info,
    59 get_virtual_path_info, get_processed_virtual_path_info and
    60 get_fields_from_path to return Unicode data decoded using the optional
    61 encoding parameter or a common default encoding.
    62 Added convenience methods to Transaction for the decoding and encoding of path
    63 values (to and from Unicode objects) - see the decode_path and encode_path
    64 methods.
    65 Added the notion of processed virtual path info - the part of the original
    66 path info not represented in the current virtual path info.
    67 Added "pass through" behaviour to ResourceMap.MapResource (prompted by a patch
    68 from Scott Robinson).
    69 Fixed ResourceMap.MapResource to handle non-existent resources properly (where
    70 the virtual path info is only one component in length).
    71 Added Debian package support.
    72 Added automatic session directory creation for the WebStack sessions
    73 implementation.
    74 Added support for the repeated retrieval of sessions from the same WebStack
    75 session store, avoiding deadlocks.
    76 Fixed the calendar example, making it perform a proper function.
    77 
    78 New in WebStack 0.10 (Changes since WebStack 0.9)
    79 -------------------------------------------------
    80 
    81 Changes to make the tools/demo.py script work on Windows (and other) platforms
    82 (suggested by Jim Madsen).
    83 Fixed end of header newlines for CGI (suggested by Matt Harrison).
    84 Minor documentation fixes and improvements, adding information on AOLserver in
    85 the CGI and Webware notes.
    86 Changed the mod_python server name method to use the server object rather than
    87 the connection object.
    88 Added a parameter to the ResourceMap.MapResource class to permit automatic
    89 redirects into resource hierarchies when no trailing "/" was given in the URL;
    90 changed the updated virtual path info so that empty values may be set (the
    91 guarantee that "/" will always appear no longer applies).
    92 Fixed virtual path info retrieval when the value is an empty string.
    93 
    94 New in WebStack 0.9 (Changes since WebStack 0.8)
    95 ------------------------------------------------
    96 
    97 Standardised error handling in the adapters so that tracebacks can be
    98 suppressed and an internal server error condition raised.
    99 Added overriding of path info in transactions.
   100 Added a ResourceMap resource for dispatching to different resources
   101 according to path components.
   102 Standardised deployment for some frameworks (see docs/deploying.html).
   103 Introductory documentation in XHTML format.
   104 Added server name and port methods to the transaction.
   105 Added a simple demonstration application, incorporating many of the examples
   106 and launched under a single script.
   107 Fixed mod_python native sessions.
   108 Fixed Zope request stream access.
   109 WebStack is now licensed under the LGPL - see docs/COPYING.txt for details.
   110 
   111 New in WebStack 0.8 (Changes since WebStack 0.7)
   112 ------------------------------------------------
   113 
   114 Added a standard exception, EndOfResponse, which can be used to immediately
   115 stop the processing/production of a response; this is useful when resources
   116 need to issue a redirect without unnecessary content being generated, for
   117 example.
   118 Fixed path information for Zope.
   119 Added WSGI support.
   120 Verified Twisted 1.3.0 support with Python 2.3.3.
   121 
   122 New in WebStack 0.7 (Changes since WebStack 0.6)
   123 ------------------------------------------------
   124 
   125 Fixed path information semantics.
   126 Fixed file upload semantics.
   127 Fixed content type handling for Unicode output and for interpreting request
   128 body fields/parameters (although some improvement remains).
   129 Added a method to discover the chosen response stream encoding.
   130 Fixed field/parameter retrieval so that path and body fields are distinct,
   131 regardless of the framework employed.
   132 Added a method to get a combination of path and body fields (suggested by
   133 Jacob Smullyan).
   134 Introduced Zope 2 support.
   135 Improved Jython/Java Servlet API support (although a special PyServlet class
   136 must now be used, and certain libraries must be deployed with applications).
   137 Introduced authentication/authorisation support for Jython/Java Servlet API.
   138 Session support has been added (except for Webware 0.8.1).
   139 Alternative cookie support for mod_python has been added.
   140 Cookie support now supports encoded Unicode sequences for names and values.
   141 
   142 New in WebStack 0.6 (Changes since WebStack 0.5)
   143 ------------------------------------------------
   144 
   145 Introduced Jython/Java Servlet API support.
   146 Minor fixes to example applications and to BaseHTTPRequestHandler.
   147 
   148 New in WebStack 0.5 (Changes since WebStack 0.4)
   149 ------------------------------------------------
   150 
   151 Changed request body fields/parameters so that they are now represented
   152 using Unicode objects rather than plain strings.
   153 Introduced better support for Unicode in response streams.
   154 
   155 New in WebStack 0.4 (Changes since WebStack 0.3)
   156 ------------------------------------------------
   157 
   158 Added application definition of user identity, permitting alternative
   159 authentication mechanisms.
   160 Improved BaseHTTPRequestHandler and mod_python reliability around fields
   161 from request bodies.
   162 Provided stream and environment parameterisation in the CGI adapter.
   163 Added LoginRedirect and Login examples.
   164 Added get_path_without_query and fixed get_path behaviour.
   165 
   166 New in WebStack 0.3 (Changes since WebStack 0.2)
   167 ------------------------------------------------
   168 
   169 Added better header support for Webware (suggested by Ian Bicking).
   170 Introduced CGI and Java Servlet support (the latter is currently
   171 broken/unfinished).
   172 Introduced support for cookies.
   173 
   174 Future Work
   175 -----------
   176 
   177 (Essential)
   178 
   179 JythonServlet libraries need to be configured using sys.add_package when
   180 these do not feature in the compiled-in list. Adding such configuration to
   181 the handler may be most appropriate (since the web.xml file can be too
   182 arcane), but this needs testing.
   183 
   184 (Important)
   185 
   186 Things to consider for future releases: improved cookie support, redirects,
   187 access to shared resources and much better documentation.
   188 
   189 Field access needs testing, especially for anything using the
   190 cgi.FieldStorage class, and the way file uploads are exposed should be
   191 reviewed (currently the meta-data is not exposed). The acquisition of fields
   192 from specific sources should be tested with different request methods - some
   193 frameworks provide path fields in the body fields dictionary, others (eg.
   194 Zope) change the fields exposed depending on request method.
   195 
   196 Interpretation of path field encodings needs to be verified. Currently,
   197 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
   198 ISO-8859-1, but it might be the case that some such fields might be
   199 submitted as UTF-8. The decode_path method on Transaction does do much of the
   200 work that is likely to be required, however.
   201 
   202 An interesting test of encodings is to introduce things like the following to
   203 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
   204 This should produce the following decoded result: %F0?æ=ø&%F0=ø
   205 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
   206 
   207 Cookie objects need defining strictly, especially since the standard library
   208 Cookie object behaves differently to mod_python (and possibly Webware)
   209 Cookie objects. Moreover, the set_cookie_value method needs to provide
   210 access to the usual cookie parameters as supported by the frameworks. The
   211 standard library Cookie module has issues with Unicode cookie names (and
   212 possibly values) - this is worked around, but it would be best to resolve
   213 this comprehensively.
   214 
   215 UTF-16 (and possibly other encodings) causes problems with HTML form data
   216 sent in POST requests using the application/x-www-form-urlencoded content
   217 type.  This should be reviewed at a later date when proper standardisation
   218 has taken place.
   219 
   220 Session support, especially through WebStack.Helpers.Session, should be
   221 reviewed and be made compatible with non-cookie mechanisms.
   222 
   223 HeaderValue objects should be employed more extensively. Thus, the header
   224 access methods may need to change their behaviour slightly.
   225 
   226 Investigate the nicer functions in the cgi module, discarding the "magic"
   227 stuff like FieldStorage.
   228 
   229 WSGI support could demand that a special "end of headers" method be
   230 introduced into WebStack, thus making response output more efficient (and
   231 probably also for other frameworks, too).
   232 
   233 The algorithm employed in the WebStack.Helpers.Auth.get_token function
   234 should be reviewed and improved for better security.
   235 
   236 Investigate proper support for HEAD, OPTIONS and other request methods.
   237 
   238 Consider packages for different operating systems (other than Debian).
   239 
   240 (Completed/rejected)
   241 
   242 The location of deployed applications in the filesystem should be exposed to
   243 those applications. (This is actually available in the __file__ module
   244 variable.)
   245 
   246 Path information should be consistent across all frameworks, and the "path
   247 info" value should be meaningful. (This should now be correct.)
   248 
   249 Release Procedures
   250 ------------------
   251 
   252 Update the WebStack/__init__.py __version__ attribute.
   253 Change the version number and package filename/directory in the documentation.
   254 Change code examples in the documentation if appropriate.
   255 Update the release notes (see above).
   256 Check the setup.py file and ensure that all package directories are mentioned.
   257 Check the release information in the PKG-INFO file and in the package
   258 changelog (and other files).
   259 Tag, export.
   260 Generate the PyServlet classes.
   261 Generate the API documentation.
   262 Remove generated .pyc files: rm `find . -name "*.pyc"`
   263 Archive, upload.
   264 Upload the introductory documentation.
   265 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   266 
   267 Generating the API Documentation
   268 --------------------------------
   269 
   270 In order to prepare the API documentation, it is necessary to generate some
   271 Web pages from the Python source code. For this, the epydoc application must
   272 be available on your system. Then, inside the WebStack directory, run the
   273 apidocs.sh tool script as follows:
   274 
   275 ./tools/apidocs.sh
   276 
   277 Some warnings may be generated by the script, but the result should be a new
   278 apidocs directory within the WebStack directory.