XSLTools

README.txt

600:2cb1b1887117
2007-07-07 paulb [project @ 2007-07-07 16:17:24 by paulb] Relicensed under the LGPLv3 and upgraded Sarissa.
     1 Introduction
     2 ------------
     3 
     4 XSLTools is a collection of modules and packages facilitating the development
     5 of applications based on XML, XSL stylesheets and transformations, notably Web
     6 applications involving complicated Web forms potentially consisting of
     7 editable hierarchical structures and potentially involving "live" or "in-page"
     8 dynamic updates to portions of those Web forms.
     9 
    10 Quick Start
    11 -----------
    12 
    13 Try running the demo:
    14 
    15 python tools/demo.py
    16 
    17 An introductory guide to creating applications can be found in the docs
    18 directory - see docs/index.html for the start page.
    19 
    20 Contact, Copyright and Licence Information
    21 ------------------------------------------
    22 
    23 The current Web page for XSLTools at the time of release is:
    24 
    25 http://www.boddie.org.uk/python/XSLTools.html
    26 
    27 Copyright and licence information can be found in the docs directory - see
    28 docs/COPYING.txt, docs/LICENCE.txt and docs/LICENCE-Sarissa.txt for more
    29 information.
    30 
    31 Dependencies
    32 ------------
    33 
    34 XSLTools has the following basic dependencies:
    35 
    36 Packages                    Release Information
    37 --------                    -------------------
    38 
    39 libxml2dom                  0.4.3
    40 libxml2 and libxslt         Some combinations may not be reliable!
    41                             Tested with libxml2 2.6.17 and libxslt 1.1.12
    42                             Tested with libxml2 2.6.27 and libxslt 1.1.20
    43 
    44 The example Web applications require WebStack (release 1.2.3 or later).
    45 The example PyQt applications have been tested with PyQt 3.15.
    46 
    47 New in XSLTools 0.4.6 (Changes since XSLTools 0.4.5)
    48 ----------------------------------------------------
    49 
    50   * Improved the Login module, enabling the VerySimpleWithLogin example for
    51     various frameworks.
    52   * Relicensed under the LGPL version 3 or later.
    53   * Upgraded to Sarissa 0.9.7.8 (compatible with LGPL/GPL version 3).
    54 
    55 New in XSLTools 0.4.5 (Changes since XSLTools 0.4.4)
    56 ----------------------------------------------------
    57 
    58   * Fixed the result of transformations in XSLOutput: proper document nodes
    59     are now produced.
    60   * Added an XSLForms.Resources.Login module which provides resources to
    61     support login screens and redirects.
    62   * Fixed newlines in the attributes created from fields in XSLForms: CR
    63     characters are no longer included since this caused the doubling up of
    64     newlines in Firefox.
    65 
    66 New in XSLTools 0.4.4 (Changes since XSLTools 0.4.3)
    67 ----------------------------------------------------
    68 
    69   * Fixed translation selection for the template:i18n annotation attribute,
    70     not just for the template:i18n extension function - more apologies for
    71     resulting output changes!
    72   * Improved the template fixing stylesheet and added some documentation for
    73     the script and the related expr-prefix attribute.
    74   * Introduced WebStack 1.2.2 EncodingSelector and encoding changes.
    75   * Added docstring and return value for the write_month_to_document function
    76     in XSLTools.XMLCalendar.
    77 
    78 New in XSLTools 0.4.3 (Changes since XSLTools 0.4.2)
    79 ----------------------------------------------------
    80 
    81   * Fixed translation selection when an unsupported locale is specified,
    82     choosing the first locale as the default (rather than exposing the values
    83     themselves as translations). Note that this is an unfortunate and subtle
    84     change which may affect application output - apologies are hereby offered!
    85 
    86 New in XSLTools 0.4.2 (Changes since XSLTools 0.4.1)
    87 ----------------------------------------------------
    88 
    89   * Added a content type check in the XSLFormsResource class, permitting
    90     non-form-based resources to access the raw request data, rather than have
    91     the data processed unsuccessfully and consequently discarded.
    92   * Added a script and a function to fix template namespaces after editing in
    93     a careless editor.
    94   * Changed libxml2mod and libxsltmod import details to try libxmlmods -
    95     suggested by Lucian Wischik for libxml2dom.
    96 
    97 New in XSLTools 0.4.1 (Changes since XSLTools 0.4)
    98 --------------------------------------------------
    99 
   100   * Made translations specified using the template:i18n annotation take
   101     priority over template:value annotations.
   102   * Added expression-based template:i18n annotations, and provided fallback
   103     output for such translations based on the value of the evaluated
   104     expression.
   105 
   106 New in XSLTools 0.4 (Changes since XSLTools 0.3.1)
   107 --------------------------------------------------
   108 
   109   * Changed the preparation of templates to produce rule-based output
   110     stylesheets, thus permitting recursive templates. This requires an extra
   111     expr-prefix annotation to be used in certain kinds of templates.
   112   * Added a recursive template example application.
   113   * Changed fragment production to use original template documents instead of
   114     output stylesheets.
   115   * Changed the in_page_resources attribute to provide the output identifier,
   116     thus changing the prepare_fragment method in Web resources so that only
   117     the fragment identifier needs to be supplied.
   118   * Added the XSLForms.Resources.WebResources.prepare_resources method for the
   119     preparation of initialiser and output stylesheets before an application is
   120     run.
   121   * Changed selectors to not automatically create elements in the form data
   122     document unless requested to do so. Introduced a Form.get_selector
   123     method in XSLForms.Fields.
   124   * Permitted the creation of hierarchies of elements in
   125     XSLForms.Utils.add_elements.
   126   * Introduced dynamic parameter evaluation for multiple-choice fields in
   127     order to support sources of multiple-choice values which reside in the
   128     form data document itself.
   129   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
   130     editors which strip namespace prefixes.
   131   * Fixed filesystem encoding issues in the Candidate example; fixed language
   132     preference access in the Configurator and VerySimple examples.
   133   * Changed the BaseHTTPRequestHandler version of the Candidate example to
   134     store data in a subdirectory of the current working directory, thus
   135     allowing the demonstration application to work after package installation.
   136 
   137 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
   138 --------------------------------------------------
   139 
   140   * Fixed copyright and licensing information.
   141 
   142 New in XSLTools 0.3 (Changes since XSLTools 0.2)
   143 ------------------------------------------------
   144 
   145   * Introduced copying of multiple-choice value element contents so that
   146     option element labels can differ from the underlying values.
   147   * Added internationalisation support, providing the template:i18n annotation
   148     and the template:i18n extension function.
   149   * Updated the documentation to cover the above new features.
   150   * Fixed non-GET/POST request method handling in WebResources.
   151   * Added the xslform_preparemacro.py script.
   152   * Added an experimental template:range extension function.
   153 
   154 New in XSLTools 0.2 (Changes since XSLTools 0.1)
   155 ------------------------------------------------
   156 
   157   * Made a new XSLTools package and moved XSLOutput into it.
   158   * Improved serialisation of transformation results so that output options
   159     are observed (in some cases, at least).
   160   * Fixed stylesheet and reference document paths so that libxslt should not
   161     now become confused by ambiguous relative paths.
   162   * Added expression parameters to XSLOutput.Processor so that in-document
   163     data can be used to, for example, initialise multiple-choice field values.
   164   * Added input/initialiser support so that input documents can be tidied or
   165     initialised using information from the template.
   166   * Added template:init for use with template:element in XSLForms to control
   167     element initialisation where necessary.
   168   * Added special high-level "macro" attributes (eg. template:attribute-field)
   169     which should make templates easier to write and maintain.
   170   * Added template:if to XSLForms, providing conditional output of annotated
   171     elements.
   172   * Added set_document to XSLForms.Fields.Form.
   173   * Added prepare_parameters to the XSLFormsResource class in the
   174     XSLForms.Resources.WebResources module.
   175   * Added element-path, url-encode and choice XSLForms extension functions.
   176   * Improved Unicode support in the XSLForms extension functions.
   177   * Changed in-page requests to contain proper POST data.
   178   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   179   * Updated the code to work with WebStack 1.0 changes and adopted the
   180     new-style WebStack demonstration mechanism.
   181   * Added XMLCalendar and XMLTable (to the XSLTools package).
   182   * Added a dictionary (or word lookup) example application.
   183   * Added a job candidate profile (or CV editor) example application.
   184   * Added a template attribute reference and an XSLFormsResource guide to the
   185     documentation.
   186   * Added Debian package support (specifically Ubuntu package support).
   187   * Added missing COPYING.txt file.
   188   * Renamed the scripts to avoid naming issues in system-wide installations.
   189   * Added a PyQt example based on the system configurator example, with the
   190     form prepared in Qt Designer. This example runs in PyQt and in a Web
   191     environment without any changes to the application code. In-page updates
   192     are currently not implemented in the Web version, however.
   193 
   194 Notes on In-Page Update Functionality
   195 -------------------------------------
   196 
   197 Special note #1: Konqueror seems in certain cases to remember replaced form
   198 content (when replaceChild is used to replace regions of the page which
   199 include form elements). This causes the browser to believe that more form
   200 fields exist on the page than actually do so, and subsequent form submissions
   201 thus include the values of such removed fields. A special hack is in place to
   202 disable form fields by changing their names, thus causing Konqueror to not
   203 associate such fields with the real, active fields; this hack does not seem to
   204 cause problems for Mozilla. This needs some investigation to determine in
   205 exactly which circumstances the problem arises.
   206 
   207 Special note #2: Konqueror also seems to crash if asked to find elements using
   208 an empty 'id' attribute string. This needs some investigation to see if it
   209 really is the getElementById call that causes the crash.
   210 
   211 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   212 the end of field values. Attempting to prune them before the request is sent
   213 fails with a function like the following:
   214 
   215 function fixValue(fieldValue) {
   216     if (fieldValue.length == 0) {
   217         return fieldValue;
   218     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   219         return fieldValue.substr(0, fieldValue.length - 1);
   220     } else {
   221         return fieldValue;
   222     }
   223 }
   224 
   225 This may be because it is the entire message that is terminated with the null
   226 character, and that this happens only upon sending the message. Consequently,
   227 some frameworks (notably mod_python) do not support in-page functionality when
   228 used from Konqueror.
   229 
   230 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   231 XMLHttpRequest in-page updates to function unless the URL used in the
   232 requestUpdate JavaScript function is compatible with the URL at which the
   233 browser finds the application. Currently, relative URLs are in use to avoid
   234 this issue of compatibility, but should an absolute URL be deduced using the
   235 WebStack API and then used, it may be possible that the values returned by
   236 that API do not match the actual addresses entered into the address bar of the
   237 browser.
   238 
   239 To check the behaviour of the applications, it is possible to view the
   240 document source of the pages served by applications and to verify that the
   241 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   242 a relative link or involve a URL similar to that which appears in the
   243 browser's address bar. In some environments, the use of 'localhost' addresses
   244 often confuses the browser and server; one workaround is to use real host
   245 names or addresses instead of 'localhost'.
   246 
   247 Choosing an element-path:
   248 
   249 When specifying the "context" of the in-page update, one must imagine which
   250 element the template fragment should operate within. If the template:id
   251 attribute marks a particular section, then the element-path should be a path
   252 to the applicable context element for that section in the complete template
   253 document. Note that if a template:element attribute appears on the same
   254 element as the template:id attribute then the element-path should refer to the
   255 element specified in the template:element attribute.
   256 
   257 Choosing where to put template:attribute, template:id and id:
   258 
   259 When specifying the extent of a template fragment, one must be sure not to put
   260 the template:id attribute on the same element as a template:attribute
   261 annotation; otherwise, the generated code will be improperly extracted as a
   262 fragment producing two versions of the element - one for when the specified
   263 attribute is present, and one for when it is not present. Generally,
   264 template:id and id can be placed on the same node, however.
   265 
   266 Stable element ordering and element-path:
   267 
   268 Within the element-path, the numbering of the elements will start at 1.
   269 Therefore it is vital to choose a region of the form data structure with the
   270 element-path which is isolated from surrounding elements whose positions would
   271 otherwise be dependent on a stable ordering of elements, and whose processing
   272 would be disrupted if some new elements suddenly appeared claiming the same
   273 positions in the document. For example:
   274 
   275   <item value="">         .../item$1/value
   276     <type value=""/>      .../item$1/type$1/value
   277     <comment value=""/>   .../item$1/comment$2/value
   278   </item>
   279 
   280   In-page update...
   281 
   282   <comment value=""/>     .../item$1/comment$1/value
   283 
   284 Notes on XSL
   285 ------------
   286 
   287 libxslt seems to be quite liberal on the definition of runtime parameters, in
   288 that there is no apparent need to explicitly declare the corresponding global
   289 variables in stylesheets. Whilst this is nice, we may eventually need to
   290 detect such variables and add them in the preparation process.
   291 
   292 Release Procedures
   293 ------------------
   294 
   295 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   296 attributes.
   297 Change the version number and package filename/directory in the documentation.
   298 Change code examples in the documentation if appropriate.
   299 Update the release notes (see above).
   300 Check the setup.py file and ensure that all package directories are mentioned.
   301 Check the release information in the PKG-INFO file and in the package
   302 changelog (and other files).
   303 Tag, export.
   304 Generate the example resources.
   305 Generate the API documentation.
   306 Remove generated .pyc files: rm `find . -name "*.pyc"`
   307 Archive, upload.
   308 Upload the introductory documentation.
   309 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   310 
   311 Generating the Example Resources
   312 --------------------------------
   313 
   314 In order to prepare the example resources, the prepare_demo.py script must be
   315 run as follows:
   316 
   317 python tools/prepare_demo.py
   318 
   319 This will ensure that all initialiser and output stylesheets are created and
   320 are thus installed by packages.
   321 
   322 Generating the API Documentation
   323 --------------------------------
   324 
   325 In order to prepare the API documentation, it is necessary to generate some
   326 Web pages from the Python source code. For this, the epydoc application must
   327 be available on your system. Then, inside the distribution directory, run the
   328 apidocs.sh tool script as follows:
   329 
   330 ./tools/apidocs.sh
   331 
   332 Some warnings may be generated by the script, but the result should be a new
   333 apidocs directory within the distribution directory.
   334 
   335 Making Packages
   336 ---------------
   337 
   338 To make Debian-based packages:
   339 
   340   1. Create new package directories under packages if necessary.
   341   2. Make a symbolic link in the distribution's root directory to keep the
   342      Debian tools happy:
   343 
   344      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   345 
   346   3. Run the package builder:
   347 
   348      dpkg-buildpackage -rfakeroot
   349 
   350   4. Locate and tidy up the packages in the parent directory of the
   351      distribution's root directory.