XSLTools

README.txt

606:6d77bc703c54
2007-07-07 paulb [project @ 2007-07-07 17:54:42 by paulb] Attempt to fix dependency resolution.
     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                             libxslt 1.1.17 should be avoided
    44 
    45 The example Web applications require WebStack (release 1.2.3 or later).
    46 The example PyQt applications have been tested with PyQt 3.15.
    47 
    48 New in XSLTools 0.4.6 (Changes since XSLTools 0.4.5)
    49 ----------------------------------------------------
    50 
    51   * Improved the Login module, enabling the VerySimpleWithLogin example for
    52     various frameworks.
    53   * Relicensed under the LGPL version 3 or later.
    54   * Upgraded to Sarissa 0.9.7.8 (compatible with LGPL/GPL version 3), removing
    55     a test around DOMParser so that Konqueror 3.4.0 is still supported.
    56 
    57 New in XSLTools 0.4.5 (Changes since XSLTools 0.4.4)
    58 ----------------------------------------------------
    59 
    60   * Fixed the result of transformations in XSLOutput: proper document nodes
    61     are now produced.
    62   * Added an XSLForms.Resources.Login module which provides resources to
    63     support login screens and redirects.
    64   * Fixed newlines in the attributes created from fields in XSLForms: CR
    65     characters are no longer included since this caused the doubling up of
    66     newlines in Firefox.
    67 
    68 New in XSLTools 0.4.4 (Changes since XSLTools 0.4.3)
    69 ----------------------------------------------------
    70 
    71   * Fixed translation selection for the template:i18n annotation attribute,
    72     not just for the template:i18n extension function - more apologies for
    73     resulting output changes!
    74   * Improved the template fixing stylesheet and added some documentation for
    75     the script and the related expr-prefix attribute.
    76   * Introduced WebStack 1.2.2 EncodingSelector and encoding changes.
    77   * Added docstring and return value for the write_month_to_document function
    78     in XSLTools.XMLCalendar.
    79 
    80 New in XSLTools 0.4.3 (Changes since XSLTools 0.4.2)
    81 ----------------------------------------------------
    82 
    83   * Fixed translation selection when an unsupported locale is specified,
    84     choosing the first locale as the default (rather than exposing the values
    85     themselves as translations). Note that this is an unfortunate and subtle
    86     change which may affect application output - apologies are hereby offered!
    87 
    88 New in XSLTools 0.4.2 (Changes since XSLTools 0.4.1)
    89 ----------------------------------------------------
    90 
    91   * Added a content type check in the XSLFormsResource class, permitting
    92     non-form-based resources to access the raw request data, rather than have
    93     the data processed unsuccessfully and consequently discarded.
    94   * Added a script and a function to fix template namespaces after editing in
    95     a careless editor.
    96   * Changed libxml2mod and libxsltmod import details to try libxmlmods -
    97     suggested by Lucian Wischik for libxml2dom.
    98 
    99 New in XSLTools 0.4.1 (Changes since XSLTools 0.4)
   100 --------------------------------------------------
   101 
   102   * Made translations specified using the template:i18n annotation take
   103     priority over template:value annotations.
   104   * Added expression-based template:i18n annotations, and provided fallback
   105     output for such translations based on the value of the evaluated
   106     expression.
   107 
   108 New in XSLTools 0.4 (Changes since XSLTools 0.3.1)
   109 --------------------------------------------------
   110 
   111   * Changed the preparation of templates to produce rule-based output
   112     stylesheets, thus permitting recursive templates. This requires an extra
   113     expr-prefix annotation to be used in certain kinds of templates.
   114   * Added a recursive template example application.
   115   * Changed fragment production to use original template documents instead of
   116     output stylesheets.
   117   * Changed the in_page_resources attribute to provide the output identifier,
   118     thus changing the prepare_fragment method in Web resources so that only
   119     the fragment identifier needs to be supplied.
   120   * Added the XSLForms.Resources.WebResources.prepare_resources method for the
   121     preparation of initialiser and output stylesheets before an application is
   122     run.
   123   * Changed selectors to not automatically create elements in the form data
   124     document unless requested to do so. Introduced a Form.get_selector
   125     method in XSLForms.Fields.
   126   * Permitted the creation of hierarchies of elements in
   127     XSLForms.Utils.add_elements.
   128   * Introduced dynamic parameter evaluation for multiple-choice fields in
   129     order to support sources of multiple-choice values which reside in the
   130     form data document itself.
   131   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
   132     editors which strip namespace prefixes.
   133   * Fixed filesystem encoding issues in the Candidate example; fixed language
   134     preference access in the Configurator and VerySimple examples.
   135   * Changed the BaseHTTPRequestHandler version of the Candidate example to
   136     store data in a subdirectory of the current working directory, thus
   137     allowing the demonstration application to work after package installation.
   138 
   139 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
   140 --------------------------------------------------
   141 
   142   * Fixed copyright and licensing information.
   143 
   144 New in XSLTools 0.3 (Changes since XSLTools 0.2)
   145 ------------------------------------------------
   146 
   147   * Introduced copying of multiple-choice value element contents so that
   148     option element labels can differ from the underlying values.
   149   * Added internationalisation support, providing the template:i18n annotation
   150     and the template:i18n extension function.
   151   * Updated the documentation to cover the above new features.
   152   * Fixed non-GET/POST request method handling in WebResources.
   153   * Added the xslform_preparemacro.py script.
   154   * Added an experimental template:range extension function.
   155 
   156 New in XSLTools 0.2 (Changes since XSLTools 0.1)
   157 ------------------------------------------------
   158 
   159   * Made a new XSLTools package and moved XSLOutput into it.
   160   * Improved serialisation of transformation results so that output options
   161     are observed (in some cases, at least).
   162   * Fixed stylesheet and reference document paths so that libxslt should not
   163     now become confused by ambiguous relative paths.
   164   * Added expression parameters to XSLOutput.Processor so that in-document
   165     data can be used to, for example, initialise multiple-choice field values.
   166   * Added input/initialiser support so that input documents can be tidied or
   167     initialised using information from the template.
   168   * Added template:init for use with template:element in XSLForms to control
   169     element initialisation where necessary.
   170   * Added special high-level "macro" attributes (eg. template:attribute-field)
   171     which should make templates easier to write and maintain.
   172   * Added template:if to XSLForms, providing conditional output of annotated
   173     elements.
   174   * Added set_document to XSLForms.Fields.Form.
   175   * Added prepare_parameters to the XSLFormsResource class in the
   176     XSLForms.Resources.WebResources module.
   177   * Added element-path, url-encode and choice XSLForms extension functions.
   178   * Improved Unicode support in the XSLForms extension functions.
   179   * Changed in-page requests to contain proper POST data.
   180   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   181   * Updated the code to work with WebStack 1.0 changes and adopted the
   182     new-style WebStack demonstration mechanism.
   183   * Added XMLCalendar and XMLTable (to the XSLTools package).
   184   * Added a dictionary (or word lookup) example application.
   185   * Added a job candidate profile (or CV editor) example application.
   186   * Added a template attribute reference and an XSLFormsResource guide to the
   187     documentation.
   188   * Added Debian package support (specifically Ubuntu package support).
   189   * Added missing COPYING.txt file.
   190   * Renamed the scripts to avoid naming issues in system-wide installations.
   191   * Added a PyQt example based on the system configurator example, with the
   192     form prepared in Qt Designer. This example runs in PyQt and in a Web
   193     environment without any changes to the application code. In-page updates
   194     are currently not implemented in the Web version, however.
   195 
   196 Notes on In-Page Update Functionality
   197 -------------------------------------
   198 
   199 Special note #1: Konqueror seems in certain cases to remember replaced form
   200 content (when replaceChild is used to replace regions of the page which
   201 include form elements). This causes the browser to believe that more form
   202 fields exist on the page than actually do so, and subsequent form submissions
   203 thus include the values of such removed fields. A special hack is in place to
   204 disable form fields by changing their names, thus causing Konqueror to not
   205 associate such fields with the real, active fields; this hack does not seem to
   206 cause problems for Mozilla. This needs some investigation to determine in
   207 exactly which circumstances the problem arises.
   208 
   209 Special note #2: Konqueror also seems to crash if asked to find elements using
   210 an empty 'id' attribute string. This needs some investigation to see if it
   211 really is the getElementById call that causes the crash.
   212 
   213 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   214 the end of field values. Attempting to prune them before the request is sent
   215 fails with a function like the following:
   216 
   217 function fixValue(fieldValue) {
   218     if (fieldValue.length == 0) {
   219         return fieldValue;
   220     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   221         return fieldValue.substr(0, fieldValue.length - 1);
   222     } else {
   223         return fieldValue;
   224     }
   225 }
   226 
   227 This may be because it is the entire message that is terminated with the null
   228 character, and that this happens only upon sending the message. Consequently,
   229 some frameworks (notably mod_python) do not support in-page functionality when
   230 used from Konqueror.
   231 
   232 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   233 XMLHttpRequest in-page updates to function unless the URL used in the
   234 requestUpdate JavaScript function is compatible with the URL at which the
   235 browser finds the application. Currently, relative URLs are in use to avoid
   236 this issue of compatibility, but should an absolute URL be deduced using the
   237 WebStack API and then used, it may be possible that the values returned by
   238 that API do not match the actual addresses entered into the address bar of the
   239 browser.
   240 
   241 To check the behaviour of the applications, it is possible to view the
   242 document source of the pages served by applications and to verify that the
   243 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   244 a relative link or involve a URL similar to that which appears in the
   245 browser's address bar. In some environments, the use of 'localhost' addresses
   246 often confuses the browser and server; one workaround is to use real host
   247 names or addresses instead of 'localhost'.
   248 
   249 Choosing an element-path:
   250 
   251 When specifying the "context" of the in-page update, one must imagine which
   252 element the template fragment should operate within. If the template:id
   253 attribute marks a particular section, then the element-path should be a path
   254 to the applicable context element for that section in the complete template
   255 document. Note that if a template:element attribute appears on the same
   256 element as the template:id attribute then the element-path should refer to the
   257 element specified in the template:element attribute.
   258 
   259 Choosing where to put template:attribute, template:id and id:
   260 
   261 When specifying the extent of a template fragment, one must be sure not to put
   262 the template:id attribute on the same element as a template:attribute
   263 annotation; otherwise, the generated code will be improperly extracted as a
   264 fragment producing two versions of the element - one for when the specified
   265 attribute is present, and one for when it is not present. Generally,
   266 template:id and id can be placed on the same node, however.
   267 
   268 Stable element ordering and element-path:
   269 
   270 Within the element-path, the numbering of the elements will start at 1.
   271 Therefore it is vital to choose a region of the form data structure with the
   272 element-path which is isolated from surrounding elements whose positions would
   273 otherwise be dependent on a stable ordering of elements, and whose processing
   274 would be disrupted if some new elements suddenly appeared claiming the same
   275 positions in the document. For example:
   276 
   277   <item value="">         .../item$1/value
   278     <type value=""/>      .../item$1/type$1/value
   279     <comment value=""/>   .../item$1/comment$2/value
   280   </item>
   281 
   282   In-page update...
   283 
   284   <comment value=""/>     .../item$1/comment$1/value
   285 
   286 Notes on XSL
   287 ------------
   288 
   289 libxslt seems to be quite liberal on the definition of runtime parameters, in
   290 that there is no apparent need to explicitly declare the corresponding global
   291 variables in stylesheets. Whilst this is nice, we may eventually need to
   292 detect such variables and add them in the preparation process.
   293 
   294 Release Procedures
   295 ------------------
   296 
   297 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   298 attributes.
   299 Change the version number and package filename/directory in the documentation.
   300 Change code examples in the documentation if appropriate.
   301 Update the release notes (see above).
   302 Check the setup.py file and ensure that all package directories are mentioned.
   303 Check the release information in the PKG-INFO file and in the package
   304 changelog (and other files).
   305 Tag, export.
   306 Generate the example resources.
   307 Generate the API documentation.
   308 Remove generated .pyc files: rm `find . -name "*.pyc"`
   309 Archive, upload.
   310 Upload the introductory documentation.
   311 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   312 
   313 Generating the Example Resources
   314 --------------------------------
   315 
   316 In order to prepare the example resources, the prepare_demo.py script must be
   317 run as follows:
   318 
   319 python tools/prepare_demo.py
   320 
   321 This will ensure that all initialiser and output stylesheets are created and
   322 are thus installed by packages.
   323 
   324 Generating the API Documentation
   325 --------------------------------
   326 
   327 In order to prepare the API documentation, it is necessary to generate some
   328 Web pages from the Python source code. For this, the epydoc application must
   329 be available on your system. Then, inside the distribution directory, run the
   330 apidocs.sh tool script as follows:
   331 
   332 ./tools/apidocs.sh
   333 
   334 Some warnings may be generated by the script, but the result should be a new
   335 apidocs directory within the distribution directory.
   336 
   337 Making Packages
   338 ---------------
   339 
   340 To make Debian-based packages:
   341 
   342   1. Create new package directories under packages if necessary.
   343   2. Make a symbolic link in the distribution's root directory to keep the
   344      Debian tools happy:
   345 
   346      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   347 
   348   3. Run the package builder:
   349 
   350      dpkg-buildpackage -rfakeroot
   351 
   352   4. Locate and tidy up the packages in the parent directory of the
   353      distribution's root directory.