XSLTools

README.txt

570:bcf46ac5b49e
2007-04-12 paulb [project @ 2007-04-12 18:41:40 by paulb] Fixed the adoption of low-level nodes so that real document nodes are produced. Updated release information.
     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                  0.3.3 (0.3.6 recommended)
    40 libxml2                     Tested with 2.6.17
    41 libxslt                     Tested with 1.1.12
    42 
    43 The example Web applications require WebStack (release 1.2.2 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 
    52 New in XSLTools 0.4.4 (Changes since XSLTools 0.4.3)
    53 ----------------------------------------------------
    54 
    55   * Fixed translation selection for the template:i18n annotation attribute,
    56     not just for the template:i18n extension function - more apologies for
    57     resulting output changes!
    58   * Improved the template fixing stylesheet and added some documentation for
    59     the script and the related expr-prefix attribute.
    60   * Introduced WebStack 1.2.2 EncodingSelector and encoding changes.
    61   * Added docstring and return value for the write_month_to_document function
    62     in XSLTools.XMLCalendar.
    63 
    64 New in XSLTools 0.4.3 (Changes since XSLTools 0.4.2)
    65 ----------------------------------------------------
    66 
    67   * Fixed translation selection when an unsupported locale is specified,
    68     choosing the first locale as the default (rather than exposing the values
    69     themselves as translations). Note that this is an unfortunate and subtle
    70     change which may affect application output - apologies are hereby offered!
    71 
    72 New in XSLTools 0.4.2 (Changes since XSLTools 0.4.1)
    73 ----------------------------------------------------
    74 
    75   * Added a content type check in the XSLFormsResource class, permitting
    76     non-form-based resources to access the raw request data, rather than have
    77     the data processed unsuccessfully and consequently discarded.
    78   * Added a script and a function to fix template namespaces after editing in
    79     a careless editor.
    80   * Changed libxml2mod and libxsltmod import details to try libxmlmods -
    81     suggested by Lucian Wischik for libxml2dom.
    82 
    83 New in XSLTools 0.4.1 (Changes since XSLTools 0.4)
    84 --------------------------------------------------
    85 
    86   * Made translations specified using the template:i18n annotation take
    87     priority over template:value annotations.
    88   * Added expression-based template:i18n annotations, and provided fallback
    89     output for such translations based on the value of the evaluated
    90     expression.
    91 
    92 New in XSLTools 0.4 (Changes since XSLTools 0.3.1)
    93 --------------------------------------------------
    94 
    95   * Changed the preparation of templates to produce rule-based output
    96     stylesheets, thus permitting recursive templates. This requires an extra
    97     expr-prefix annotation to be used in certain kinds of templates.
    98   * Added a recursive template example application.
    99   * Changed fragment production to use original template documents instead of
   100     output stylesheets.
   101   * Changed the in_page_resources attribute to provide the output identifier,
   102     thus changing the prepare_fragment method in Web resources so that only
   103     the fragment identifier needs to be supplied.
   104   * Added the XSLForms.Resources.WebResources.prepare_resources method for the
   105     preparation of initialiser and output stylesheets before an application is
   106     run.
   107   * Changed selectors to not automatically create elements in the form data
   108     document unless requested to do so. Introduced a Form.get_selector
   109     method in XSLForms.Fields.
   110   * Permitted the creation of hierarchies of elements in
   111     XSLForms.Utils.add_elements.
   112   * Introduced dynamic parameter evaluation for multiple-choice fields in
   113     order to support sources of multiple-choice values which reside in the
   114     form data document itself.
   115   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
   116     editors which strip namespace prefixes.
   117   * Fixed filesystem encoding issues in the Candidate example; fixed language
   118     preference access in the Configurator and VerySimple examples.
   119   * Changed the BaseHTTPRequestHandler version of the Candidate example to
   120     store data in a subdirectory of the current working directory, thus
   121     allowing the demonstration application to work after package installation.
   122 
   123 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
   124 --------------------------------------------------
   125 
   126   * Fixed copyright and licensing information.
   127 
   128 New in XSLTools 0.3 (Changes since XSLTools 0.2)
   129 ------------------------------------------------
   130 
   131   * Introduced copying of multiple-choice value element contents so that
   132     option element labels can differ from the underlying values.
   133   * Added internationalisation support, providing the template:i18n annotation
   134     and the template:i18n extension function.
   135   * Updated the documentation to cover the above new features.
   136   * Fixed non-GET/POST request method handling in WebResources.
   137   * Added the xslform_preparemacro.py script.
   138   * Added an experimental template:range extension function.
   139 
   140 New in XSLTools 0.2 (Changes since XSLTools 0.1)
   141 ------------------------------------------------
   142 
   143   * Made a new XSLTools package and moved XSLOutput into it.
   144   * Improved serialisation of transformation results so that output options
   145     are observed (in some cases, at least).
   146   * Fixed stylesheet and reference document paths so that libxslt should not
   147     now become confused by ambiguous relative paths.
   148   * Added expression parameters to XSLOutput.Processor so that in-document
   149     data can be used to, for example, initialise multiple-choice field values.
   150   * Added input/initialiser support so that input documents can be tidied or
   151     initialised using information from the template.
   152   * Added template:init for use with template:element in XSLForms to control
   153     element initialisation where necessary.
   154   * Added special high-level "macro" attributes (eg. template:attribute-field)
   155     which should make templates easier to write and maintain.
   156   * Added template:if to XSLForms, providing conditional output of annotated
   157     elements.
   158   * Added set_document to XSLForms.Fields.Form.
   159   * Added prepare_parameters to the XSLFormsResource class in the
   160     XSLForms.Resources.WebResources module.
   161   * Added element-path, url-encode and choice XSLForms extension functions.
   162   * Improved Unicode support in the XSLForms extension functions.
   163   * Changed in-page requests to contain proper POST data.
   164   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   165   * Updated the code to work with WebStack 1.0 changes and adopted the
   166     new-style WebStack demonstration mechanism.
   167   * Added XMLCalendar and XMLTable (to the XSLTools package).
   168   * Added a dictionary (or word lookup) example application.
   169   * Added a job candidate profile (or CV editor) example application.
   170   * Added a template attribute reference and an XSLFormsResource guide to the
   171     documentation.
   172   * Added Debian package support (specifically Ubuntu package support).
   173   * Added missing COPYING.txt file.
   174   * Renamed the scripts to avoid naming issues in system-wide installations.
   175   * Added a PyQt example based on the system configurator example, with the
   176     form prepared in Qt Designer. This example runs in PyQt and in a Web
   177     environment without any changes to the application code. In-page updates
   178     are currently not implemented in the Web version, however.
   179 
   180 Notes on In-Page Update Functionality
   181 -------------------------------------
   182 
   183 Special note #1: Konqueror seems in certain cases to remember replaced form
   184 content (when replaceChild is used to replace regions of the page which
   185 include form elements). This causes the browser to believe that more form
   186 fields exist on the page than actually do so, and subsequent form submissions
   187 thus include the values of such removed fields. A special hack is in place to
   188 disable form fields by changing their names, thus causing Konqueror to not
   189 associate such fields with the real, active fields; this hack does not seem to
   190 cause problems for Mozilla. This needs some investigation to determine in
   191 exactly which circumstances the problem arises.
   192 
   193 Special note #2: Konqueror also seems to crash if asked to find elements using
   194 an empty 'id' attribute string. This needs some investigation to see if it
   195 really is the getElementById call that causes the crash.
   196 
   197 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   198 the end of field values. Attempting to prune them before the request is sent
   199 fails with a function like the following:
   200 
   201 function fixValue(fieldValue) {
   202     if (fieldValue.length == 0) {
   203         return fieldValue;
   204     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   205         return fieldValue.substr(0, fieldValue.length - 1);
   206     } else {
   207         return fieldValue;
   208     }
   209 }
   210 
   211 This may be because it is the entire message that is terminated with the null
   212 character, and that this happens only upon sending the message. Consequently,
   213 some frameworks (notably mod_python) do not support in-page functionality when
   214 used from Konqueror.
   215 
   216 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   217 XMLHttpRequest in-page updates to function unless the URL used in the
   218 requestUpdate JavaScript function is compatible with the URL at which the
   219 browser finds the application. Currently, relative URLs are in use to avoid
   220 this issue of compatibility, but should an absolute URL be deduced using the
   221 WebStack API and then used, it may be possible that the values returned by
   222 that API do not match the actual addresses entered into the address bar of the
   223 browser.
   224 
   225 To check the behaviour of the applications, it is possible to view the
   226 document source of the pages served by applications and to verify that the
   227 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   228 a relative link or involve a URL similar to that which appears in the
   229 browser's address bar. In some environments, the use of 'localhost' addresses
   230 often confuses the browser and server; one workaround is to use real host
   231 names or addresses instead of 'localhost'.
   232 
   233 Choosing an element-path:
   234 
   235 When specifying the "context" of the in-page update, one must imagine which
   236 element the template fragment should operate within. If the template:id
   237 attribute marks a particular section, then the element-path should be a path
   238 to the applicable context element for that section in the complete template
   239 document. Note that if a template:element attribute appears on the same
   240 element as the template:id attribute then the element-path should refer to the
   241 element specified in the template:element attribute.
   242 
   243 Choosing where to put template:attribute, template:id and id:
   244 
   245 When specifying the extent of a template fragment, one must be sure not to put
   246 the template:id attribute on the same element as a template:attribute
   247 annotation; otherwise, the generated code will be improperly extracted as a
   248 fragment producing two versions of the element - one for when the specified
   249 attribute is present, and one for when it is not present. Generally,
   250 template:id and id can be placed on the same node, however.
   251 
   252 Stable element ordering and element-path:
   253 
   254 Within the element-path, the numbering of the elements will start at 1.
   255 Therefore it is vital to choose a region of the form data structure with the
   256 element-path which is isolated from surrounding elements whose positions would
   257 otherwise be dependent on a stable ordering of elements, and whose processing
   258 would be disrupted if some new elements suddenly appeared claiming the same
   259 positions in the document. For example:
   260 
   261   <item value="">         .../item$1/value
   262     <type value=""/>      .../item$1/type$1/value
   263     <comment value=""/>   .../item$1/comment$2/value
   264   </item>
   265 
   266   In-page update...
   267 
   268   <comment value=""/>     .../item$1/comment$1/value
   269 
   270 Notes on XSL
   271 ------------
   272 
   273 libxslt seems to be quite liberal on the definition of runtime parameters, in
   274 that there is no apparent need to explicitly declare the corresponding global
   275 variables in stylesheets. Whilst this is nice, we may eventually need to
   276 detect such variables and add them in the preparation process.
   277 
   278 Release Procedures
   279 ------------------
   280 
   281 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   282 attributes.
   283 Change the version number and package filename/directory in the documentation.
   284 Change code examples in the documentation if appropriate.
   285 Update the release notes (see above).
   286 Check the setup.py file and ensure that all package directories are mentioned.
   287 Check the release information in the PKG-INFO file and in the package
   288 changelog (and other files).
   289 Tag, export.
   290 Generate the example resources.
   291 Generate the API documentation.
   292 Remove generated .pyc files: rm `find . -name "*.pyc"`
   293 Archive, upload.
   294 Upload the introductory documentation.
   295 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   296 
   297 Generating the Example Resources
   298 --------------------------------
   299 
   300 In order to prepare the example resources, the prepare_demo.py script must be
   301 run as follows:
   302 
   303 python tools/prepare_demo.py
   304 
   305 This will ensure that all initialiser and output stylesheets are created and
   306 are thus installed by packages.
   307 
   308 Generating the API Documentation
   309 --------------------------------
   310 
   311 In order to prepare the API documentation, it is necessary to generate some
   312 Web pages from the Python source code. For this, the epydoc application must
   313 be available on your system. Then, inside the distribution directory, run the
   314 apidocs.sh tool script as follows:
   315 
   316 ./tools/apidocs.sh
   317 
   318 Some warnings may be generated by the script, but the result should be a new
   319 apidocs directory within the distribution directory.
   320 
   321 Making Packages
   322 ---------------
   323 
   324 To make Debian-based packages:
   325 
   326   1. Create new package directories under packages if necessary.
   327   2. Make a symbolic link in the distribution's root directory to keep the
   328      Debian tools happy:
   329 
   330      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   331 
   332   3. Run the package builder:
   333 
   334      dpkg-buildpackage -rfakeroot
   335 
   336   4. Locate and tidy up the packages in the parent directory of the
   337      distribution's root directory.