XSLTools

README.txt

553:25081e4d49a0
2008-06-21 Paul Boddie Added tag rel-0-4-3 for changeset f0e70be7a4ba
     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 1.2.1 or later).
    44 The example PyQt applications have been tested with PyQt 3.15.
    45 
    46 New in XSLTools 0.4.3 (Changes since XSLTools 0.4.2)
    47 ----------------------------------------------------
    48 
    49   * Fixed translation selection when an unsupported locale is specified,
    50     choosing the first locale as the default (rather than exposing the values
    51     themselves as translations). Note that this is an unfortunate and subtle
    52     change which may affect application output - apologies are hereby offered!
    53 
    54 New in XSLTools 0.4.2 (Changes since XSLTools 0.4.1)
    55 ----------------------------------------------------
    56 
    57   * Added a content type check in the XSLFormsResource class, permitting
    58     non-form-based resources to access the raw request data, rather than have
    59     the data processed unsuccessfully and consequently discarded.
    60   * Added a script and a function to fix template namespaces after editing in
    61     a careless editor.
    62   * Changed libxml2mod and libxsltmod import details to try libxmlmods -
    63     suggested by Lucian Wischik for libxml2dom.
    64 
    65 New in XSLTools 0.4.1 (Changes since XSLTools 0.4)
    66 --------------------------------------------------
    67 
    68   * Made translations specified using the template:i18n annotation take
    69     priority over template:value annotations.
    70   * Added expression-based template:i18n annotations, and provided fallback
    71     output for such translations based on the value of the evaluated
    72     expression.
    73 
    74 New in XSLTools 0.4 (Changes since XSLTools 0.3.1)
    75 --------------------------------------------------
    76 
    77   * Changed the preparation of templates to produce rule-based output
    78     stylesheets, thus permitting recursive templates. This requires an extra
    79     expr-prefix annotation to be used in certain kinds of templates.
    80   * Added a recursive template example application.
    81   * Changed fragment production to use original template documents instead of
    82     output stylesheets.
    83   * Changed the in_page_resources attribute to provide the output identifier,
    84     thus changing the prepare_fragment method in Web resources so that only
    85     the fragment identifier needs to be supplied.
    86   * Added the XSLForms.Resources.WebResources.prepare_resources method for the
    87     preparation of initialiser and output stylesheets before an application is
    88     run.
    89   * Changed selectors to not automatically create elements in the form data
    90     document unless requested to do so. Introduced a Form.get_selector
    91     method in XSLForms.Fields.
    92   * Permitted the creation of hierarchies of elements in
    93     XSLForms.Utils.add_elements.
    94   * Introduced dynamic parameter evaluation for multiple-choice fields in
    95     order to support sources of multiple-choice values which reside in the
    96     form data document itself.
    97   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
    98     editors which strip namespace prefixes.
    99   * Fixed filesystem encoding issues in the Candidate example; fixed language
   100     preference access in the Configurator and VerySimple examples.
   101   * Changed the BaseHTTPRequestHandler version of the Candidate example to
   102     store data in a subdirectory of the current working directory, thus
   103     allowing the demonstration application to work after package installation.
   104 
   105 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
   106 --------------------------------------------------
   107 
   108   * Fixed copyright and licensing information.
   109 
   110 New in XSLTools 0.3 (Changes since XSLTools 0.2)
   111 ------------------------------------------------
   112 
   113   * Introduced copying of multiple-choice value element contents so that
   114     option element labels can differ from the underlying values.
   115   * Added internationalisation support, providing the template:i18n annotation
   116     and the template:i18n extension function.
   117   * Updated the documentation to cover the above new features.
   118   * Fixed non-GET/POST request method handling in WebResources.
   119   * Added the xslform_preparemacro.py script.
   120   * Added an experimental template:range extension function.
   121 
   122 New in XSLTools 0.2 (Changes since XSLTools 0.1)
   123 ------------------------------------------------
   124 
   125   * Made a new XSLTools package and moved XSLOutput into it.
   126   * Improved serialisation of transformation results so that output options
   127     are observed (in some cases, at least).
   128   * Fixed stylesheet and reference document paths so that libxslt should not
   129     now become confused by ambiguous relative paths.
   130   * Added expression parameters to XSLOutput.Processor so that in-document
   131     data can be used to, for example, initialise multiple-choice field values.
   132   * Added input/initialiser support so that input documents can be tidied or
   133     initialised using information from the template.
   134   * Added template:init for use with template:element in XSLForms to control
   135     element initialisation where necessary.
   136   * Added special high-level "macro" attributes (eg. template:attribute-field)
   137     which should make templates easier to write and maintain.
   138   * Added template:if to XSLForms, providing conditional output of annotated
   139     elements.
   140   * Added set_document to XSLForms.Fields.Form.
   141   * Added prepare_parameters to the XSLFormsResource class in the
   142     XSLForms.Resources.WebResources module.
   143   * Added element-path, url-encode and choice XSLForms extension functions.
   144   * Improved Unicode support in the XSLForms extension functions.
   145   * Changed in-page requests to contain proper POST data.
   146   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   147   * Updated the code to work with WebStack 1.0 changes and adopted the
   148     new-style WebStack demonstration mechanism.
   149   * Added XMLCalendar and XMLTable (to the XSLTools package).
   150   * Added a dictionary (or word lookup) example application.
   151   * Added a job candidate profile (or CV editor) example application.
   152   * Added a template attribute reference and an XSLFormsResource guide to the
   153     documentation.
   154   * Added Debian package support (specifically Ubuntu package support).
   155   * Added missing COPYING.txt file.
   156   * Renamed the scripts to avoid naming issues in system-wide installations.
   157   * Added a PyQt example based on the system configurator example, with the
   158     form prepared in Qt Designer. This example runs in PyQt and in a Web
   159     environment without any changes to the application code. In-page updates
   160     are currently not implemented in the Web version, however.
   161 
   162 Notes on In-Page Update Functionality
   163 -------------------------------------
   164 
   165 Special note #1: Konqueror seems in certain cases to remember replaced form
   166 content (when replaceChild is used to replace regions of the page which
   167 include form elements). This causes the browser to believe that more form
   168 fields exist on the page than actually do so, and subsequent form submissions
   169 thus include the values of such removed fields. A special hack is in place to
   170 disable form fields by changing their names, thus causing Konqueror to not
   171 associate such fields with the real, active fields; this hack does not seem to
   172 cause problems for Mozilla. This needs some investigation to determine in
   173 exactly which circumstances the problem arises.
   174 
   175 Special note #2: Konqueror also seems to crash if asked to find elements using
   176 an empty 'id' attribute string. This needs some investigation to see if it
   177 really is the getElementById call that causes the crash.
   178 
   179 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   180 the end of field values. Attempting to prune them before the request is sent
   181 fails with a function like the following:
   182 
   183 function fixValue(fieldValue) {
   184     if (fieldValue.length == 0) {
   185         return fieldValue;
   186     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   187         return fieldValue.substr(0, fieldValue.length - 1);
   188     } else {
   189         return fieldValue;
   190     }
   191 }
   192 
   193 This may be because it is the entire message that is terminated with the null
   194 character, and that this happens only upon sending the message. Consequently,
   195 some frameworks (notably mod_python) do not support in-page functionality when
   196 used from Konqueror.
   197 
   198 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   199 XMLHttpRequest in-page updates to function unless the URL used in the
   200 requestUpdate JavaScript function is compatible with the URL at which the
   201 browser finds the application. Currently, relative URLs are in use to avoid
   202 this issue of compatibility, but should an absolute URL be deduced using the
   203 WebStack API and then used, it may be possible that the values returned by
   204 that API do not match the actual addresses entered into the address bar of the
   205 browser.
   206 
   207 To check the behaviour of the applications, it is possible to view the
   208 document source of the pages served by applications and to verify that the
   209 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   210 a relative link or involve a URL similar to that which appears in the
   211 browser's address bar. In some environments, the use of 'localhost' addresses
   212 often confuses the browser and server; one workaround is to use real host
   213 names or addresses instead of 'localhost'.
   214 
   215 Choosing an element-path:
   216 
   217 When specifying the "context" of the in-page update, one must imagine which
   218 element the template fragment should operate within. If the template:id
   219 attribute marks a particular section, then the element-path should be a path
   220 to the applicable context element for that section in the complete template
   221 document. Note that if a template:element attribute appears on the same
   222 element as the template:id attribute then the element-path should refer to the
   223 element specified in the template:element attribute.
   224 
   225 Choosing where to put template:attribute, template:id and id:
   226 
   227 When specifying the extent of a template fragment, one must be sure not to put
   228 the template:id attribute on the same element as a template:attribute
   229 annotation; otherwise, the generated code will be improperly extracted as a
   230 fragment producing two versions of the element - one for when the specified
   231 attribute is present, and one for when it is not present. Generally,
   232 template:id and id can be placed on the same node, however.
   233 
   234 Stable element ordering and element-path:
   235 
   236 Within the element-path, the numbering of the elements will start at 1.
   237 Therefore it is vital to choose a region of the form data structure with the
   238 element-path which is isolated from surrounding elements whose positions would
   239 otherwise be dependent on a stable ordering of elements, and whose processing
   240 would be disrupted if some new elements suddenly appeared claiming the same
   241 positions in the document. For example:
   242 
   243   <item value="">         .../item$1/value
   244     <type value=""/>      .../item$1/type$1/value
   245     <comment value=""/>   .../item$1/comment$2/value
   246   </item>
   247 
   248   In-page update...
   249 
   250   <comment value=""/>     .../item$1/comment$1/value
   251 
   252 Notes on XSL
   253 ------------
   254 
   255 libxslt seems to be quite liberal on the definition of runtime parameters, in
   256 that there is no apparent need to explicitly declare the corresponding global
   257 variables in stylesheets. Whilst this is nice, we may eventually need to
   258 detect such variables and add them in the preparation process.
   259 
   260 Release Procedures
   261 ------------------
   262 
   263 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   264 attributes.
   265 Change the version number and package filename/directory in the documentation.
   266 Change code examples in the documentation if appropriate.
   267 Update the release notes (see above).
   268 Check the setup.py file and ensure that all package directories are mentioned.
   269 Check the release information in the PKG-INFO file and in the package
   270 changelog (and other files).
   271 Tag, export.
   272 Generate the example resources.
   273 Generate the API documentation.
   274 Remove generated .pyc files: rm `find . -name "*.pyc"`
   275 Archive, upload.
   276 Upload the introductory documentation.
   277 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   278 
   279 Generating the Example Resources
   280 --------------------------------
   281 
   282 In order to prepare the example resources, the prepare_demo.py script must be
   283 run as follows:
   284 
   285 python tools/prepare_demo.py
   286 
   287 This will ensure that all initialiser and output stylesheets are created and
   288 are thus installed by packages.
   289 
   290 Generating the API Documentation
   291 --------------------------------
   292 
   293 In order to prepare the API documentation, it is necessary to generate some
   294 Web pages from the Python source code. For this, the epydoc application must
   295 be available on your system. Then, inside the distribution directory, run the
   296 apidocs.sh tool script as follows:
   297 
   298 ./tools/apidocs.sh
   299 
   300 Some warnings may be generated by the script, but the result should be a new
   301 apidocs directory within the distribution directory.
   302 
   303 Making Packages
   304 ---------------
   305 
   306 To make Debian-based packages:
   307 
   308   1. Create new package directories under packages if necessary.
   309   2. Make a symbolic link in the distribution's root directory to keep the
   310      Debian tools happy:
   311 
   312      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   313 
   314   3. Run the package builder:
   315 
   316      dpkg-buildpackage -rfakeroot
   317 
   318   4. Locate and tidy up the packages in the parent directory of the
   319      distribution's root directory.