XSLTools

README.txt

583:ddde0b1fd631
2008-06-21 Paul Boddie Added tag rel-0-4-5 for changeset aca5603e25ae
     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 Package                     Release Information
    37 -------                     -------------------
    38 
    39 libxml2dom                  0.4.3
    40 libxml2                     Tested with 2.6.17
    41 libxslt                     Tested with 1.1.12
    42 
    43 The example Web applications require WebStack (release 1.2.3 or later).
    44 The example PyQt applications have been tested with PyQt 3.15.
    45 
    46 New in XSLTools 0.4.5 (Changes since XSLTools 0.4.4)
    47 ----------------------------------------------------
    48 
    49   * Fixed the result of transformations in XSLOutput: proper document nodes
    50     are now produced.
    51   * Added an XSLForms.Resources.Login module which provides resources to
    52     support login screens and redirects.
    53   * Fixed newlines in the attributes created from fields in XSLForms: CR
    54     characters are no longer included since this caused the doubling up of
    55     newlines in Firefox.
    56 
    57 New in XSLTools 0.4.4 (Changes since XSLTools 0.4.3)
    58 ----------------------------------------------------
    59 
    60   * Fixed translation selection for the template:i18n annotation attribute,
    61     not just for the template:i18n extension function - more apologies for
    62     resulting output changes!
    63   * Improved the template fixing stylesheet and added some documentation for
    64     the script and the related expr-prefix attribute.
    65   * Introduced WebStack 1.2.2 EncodingSelector and encoding changes.
    66   * Added docstring and return value for the write_month_to_document function
    67     in XSLTools.XMLCalendar.
    68 
    69 New in XSLTools 0.4.3 (Changes since XSLTools 0.4.2)
    70 ----------------------------------------------------
    71 
    72   * Fixed translation selection when an unsupported locale is specified,
    73     choosing the first locale as the default (rather than exposing the values
    74     themselves as translations). Note that this is an unfortunate and subtle
    75     change which may affect application output - apologies are hereby offered!
    76 
    77 New in XSLTools 0.4.2 (Changes since XSLTools 0.4.1)
    78 ----------------------------------------------------
    79 
    80   * Added a content type check in the XSLFormsResource class, permitting
    81     non-form-based resources to access the raw request data, rather than have
    82     the data processed unsuccessfully and consequently discarded.
    83   * Added a script and a function to fix template namespaces after editing in
    84     a careless editor.
    85   * Changed libxml2mod and libxsltmod import details to try libxmlmods -
    86     suggested by Lucian Wischik for libxml2dom.
    87 
    88 New in XSLTools 0.4.1 (Changes since XSLTools 0.4)
    89 --------------------------------------------------
    90 
    91   * Made translations specified using the template:i18n annotation take
    92     priority over template:value annotations.
    93   * Added expression-based template:i18n annotations, and provided fallback
    94     output for such translations based on the value of the evaluated
    95     expression.
    96 
    97 New in XSLTools 0.4 (Changes since XSLTools 0.3.1)
    98 --------------------------------------------------
    99 
   100   * Changed the preparation of templates to produce rule-based output
   101     stylesheets, thus permitting recursive templates. This requires an extra
   102     expr-prefix annotation to be used in certain kinds of templates.
   103   * Added a recursive template example application.
   104   * Changed fragment production to use original template documents instead of
   105     output stylesheets.
   106   * Changed the in_page_resources attribute to provide the output identifier,
   107     thus changing the prepare_fragment method in Web resources so that only
   108     the fragment identifier needs to be supplied.
   109   * Added the XSLForms.Resources.WebResources.prepare_resources method for the
   110     preparation of initialiser and output stylesheets before an application is
   111     run.
   112   * Changed selectors to not automatically create elements in the form data
   113     document unless requested to do so. Introduced a Form.get_selector
   114     method in XSLForms.Fields.
   115   * Permitted the creation of hierarchies of elements in
   116     XSLForms.Utils.add_elements.
   117   * Introduced dynamic parameter evaluation for multiple-choice fields in
   118     order to support sources of multiple-choice values which reside in the
   119     form data document itself.
   120   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
   121     editors which strip namespace prefixes.
   122   * Fixed filesystem encoding issues in the Candidate example; fixed language
   123     preference access in the Configurator and VerySimple examples.
   124   * Changed the BaseHTTPRequestHandler version of the Candidate example to
   125     store data in a subdirectory of the current working directory, thus
   126     allowing the demonstration application to work after package installation.
   127 
   128 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
   129 --------------------------------------------------
   130 
   131   * Fixed copyright and licensing information.
   132 
   133 New in XSLTools 0.3 (Changes since XSLTools 0.2)
   134 ------------------------------------------------
   135 
   136   * Introduced copying of multiple-choice value element contents so that
   137     option element labels can differ from the underlying values.
   138   * Added internationalisation support, providing the template:i18n annotation
   139     and the template:i18n extension function.
   140   * Updated the documentation to cover the above new features.
   141   * Fixed non-GET/POST request method handling in WebResources.
   142   * Added the xslform_preparemacro.py script.
   143   * Added an experimental template:range extension function.
   144 
   145 New in XSLTools 0.2 (Changes since XSLTools 0.1)
   146 ------------------------------------------------
   147 
   148   * Made a new XSLTools package and moved XSLOutput into it.
   149   * Improved serialisation of transformation results so that output options
   150     are observed (in some cases, at least).
   151   * Fixed stylesheet and reference document paths so that libxslt should not
   152     now become confused by ambiguous relative paths.
   153   * Added expression parameters to XSLOutput.Processor so that in-document
   154     data can be used to, for example, initialise multiple-choice field values.
   155   * Added input/initialiser support so that input documents can be tidied or
   156     initialised using information from the template.
   157   * Added template:init for use with template:element in XSLForms to control
   158     element initialisation where necessary.
   159   * Added special high-level "macro" attributes (eg. template:attribute-field)
   160     which should make templates easier to write and maintain.
   161   * Added template:if to XSLForms, providing conditional output of annotated
   162     elements.
   163   * Added set_document to XSLForms.Fields.Form.
   164   * Added prepare_parameters to the XSLFormsResource class in the
   165     XSLForms.Resources.WebResources module.
   166   * Added element-path, url-encode and choice XSLForms extension functions.
   167   * Improved Unicode support in the XSLForms extension functions.
   168   * Changed in-page requests to contain proper POST data.
   169   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   170   * Updated the code to work with WebStack 1.0 changes and adopted the
   171     new-style WebStack demonstration mechanism.
   172   * Added XMLCalendar and XMLTable (to the XSLTools package).
   173   * Added a dictionary (or word lookup) example application.
   174   * Added a job candidate profile (or CV editor) example application.
   175   * Added a template attribute reference and an XSLFormsResource guide to the
   176     documentation.
   177   * Added Debian package support (specifically Ubuntu package support).
   178   * Added missing COPYING.txt file.
   179   * Renamed the scripts to avoid naming issues in system-wide installations.
   180   * Added a PyQt example based on the system configurator example, with the
   181     form prepared in Qt Designer. This example runs in PyQt and in a Web
   182     environment without any changes to the application code. In-page updates
   183     are currently not implemented in the Web version, however.
   184 
   185 Notes on In-Page Update Functionality
   186 -------------------------------------
   187 
   188 Special note #1: Konqueror seems in certain cases to remember replaced form
   189 content (when replaceChild is used to replace regions of the page which
   190 include form elements). This causes the browser to believe that more form
   191 fields exist on the page than actually do so, and subsequent form submissions
   192 thus include the values of such removed fields. A special hack is in place to
   193 disable form fields by changing their names, thus causing Konqueror to not
   194 associate such fields with the real, active fields; this hack does not seem to
   195 cause problems for Mozilla. This needs some investigation to determine in
   196 exactly which circumstances the problem arises.
   197 
   198 Special note #2: Konqueror also seems to crash if asked to find elements using
   199 an empty 'id' attribute string. This needs some investigation to see if it
   200 really is the getElementById call that causes the crash.
   201 
   202 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   203 the end of field values. Attempting to prune them before the request is sent
   204 fails with a function like the following:
   205 
   206 function fixValue(fieldValue) {
   207     if (fieldValue.length == 0) {
   208         return fieldValue;
   209     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   210         return fieldValue.substr(0, fieldValue.length - 1);
   211     } else {
   212         return fieldValue;
   213     }
   214 }
   215 
   216 This may be because it is the entire message that is terminated with the null
   217 character, and that this happens only upon sending the message. Consequently,
   218 some frameworks (notably mod_python) do not support in-page functionality when
   219 used from Konqueror.
   220 
   221 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   222 XMLHttpRequest in-page updates to function unless the URL used in the
   223 requestUpdate JavaScript function is compatible with the URL at which the
   224 browser finds the application. Currently, relative URLs are in use to avoid
   225 this issue of compatibility, but should an absolute URL be deduced using the
   226 WebStack API and then used, it may be possible that the values returned by
   227 that API do not match the actual addresses entered into the address bar of the
   228 browser.
   229 
   230 To check the behaviour of the applications, it is possible to view the
   231 document source of the pages served by applications and to verify that the
   232 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   233 a relative link or involve a URL similar to that which appears in the
   234 browser's address bar. In some environments, the use of 'localhost' addresses
   235 often confuses the browser and server; one workaround is to use real host
   236 names or addresses instead of 'localhost'.
   237 
   238 Choosing an element-path:
   239 
   240 When specifying the "context" of the in-page update, one must imagine which
   241 element the template fragment should operate within. If the template:id
   242 attribute marks a particular section, then the element-path should be a path
   243 to the applicable context element for that section in the complete template
   244 document. Note that if a template:element attribute appears on the same
   245 element as the template:id attribute then the element-path should refer to the
   246 element specified in the template:element attribute.
   247 
   248 Choosing where to put template:attribute, template:id and id:
   249 
   250 When specifying the extent of a template fragment, one must be sure not to put
   251 the template:id attribute on the same element as a template:attribute
   252 annotation; otherwise, the generated code will be improperly extracted as a
   253 fragment producing two versions of the element - one for when the specified
   254 attribute is present, and one for when it is not present. Generally,
   255 template:id and id can be placed on the same node, however.
   256 
   257 Stable element ordering and element-path:
   258 
   259 Within the element-path, the numbering of the elements will start at 1.
   260 Therefore it is vital to choose a region of the form data structure with the
   261 element-path which is isolated from surrounding elements whose positions would
   262 otherwise be dependent on a stable ordering of elements, and whose processing
   263 would be disrupted if some new elements suddenly appeared claiming the same
   264 positions in the document. For example:
   265 
   266   <item value="">         .../item$1/value
   267     <type value=""/>      .../item$1/type$1/value
   268     <comment value=""/>   .../item$1/comment$2/value
   269   </item>
   270 
   271   In-page update...
   272 
   273   <comment value=""/>     .../item$1/comment$1/value
   274 
   275 Notes on XSL
   276 ------------
   277 
   278 libxslt seems to be quite liberal on the definition of runtime parameters, in
   279 that there is no apparent need to explicitly declare the corresponding global
   280 variables in stylesheets. Whilst this is nice, we may eventually need to
   281 detect such variables and add them in the preparation process.
   282 
   283 Release Procedures
   284 ------------------
   285 
   286 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   287 attributes.
   288 Change the version number and package filename/directory in the documentation.
   289 Change code examples in the documentation if appropriate.
   290 Update the release notes (see above).
   291 Check the setup.py file and ensure that all package directories are mentioned.
   292 Check the release information in the PKG-INFO file and in the package
   293 changelog (and other files).
   294 Tag, export.
   295 Generate the example resources.
   296 Generate the API documentation.
   297 Remove generated .pyc files: rm `find . -name "*.pyc"`
   298 Archive, upload.
   299 Upload the introductory documentation.
   300 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   301 
   302 Generating the Example Resources
   303 --------------------------------
   304 
   305 In order to prepare the example resources, the prepare_demo.py script must be
   306 run as follows:
   307 
   308 python tools/prepare_demo.py
   309 
   310 This will ensure that all initialiser and output stylesheets are created and
   311 are thus installed by packages.
   312 
   313 Generating the API Documentation
   314 --------------------------------
   315 
   316 In order to prepare the API documentation, it is necessary to generate some
   317 Web pages from the Python source code. For this, the epydoc application must
   318 be available on your system. Then, inside the distribution directory, run the
   319 apidocs.sh tool script as follows:
   320 
   321 ./tools/apidocs.sh
   322 
   323 Some warnings may be generated by the script, but the result should be a new
   324 apidocs directory within the distribution directory.
   325 
   326 Making Packages
   327 ---------------
   328 
   329 To make Debian-based packages:
   330 
   331   1. Create new package directories under packages if necessary.
   332   2. Make a symbolic link in the distribution's root directory to keep the
   333      Debian tools happy:
   334 
   335      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   336 
   337   3. Run the package builder:
   338 
   339      dpkg-buildpackage -rfakeroot
   340 
   341   4. Locate and tidy up the packages in the parent directory of the
   342      distribution's root directory.