XSLTools

README.txt

557:60371d21572e
2007-01-19 paulb [project @ 2007-01-19 22:22:51 by paulb] Documented expr-prefix and the xslform_fix.py script. 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 1.2.1 or later).
    44 The example PyQt applications have been tested with PyQt 3.15.
    45 
    46 New in XSLTools 0.4.4 (Changes since XSLTools 0.4.3)
    47 ----------------------------------------------------
    48 
    49   * Improved the template fixing stylesheet and added some documentation for
    50     the script and the related expr-prefix attribute.
    51 
    52 New in XSLTools 0.4.3 (Changes since XSLTools 0.4.2)
    53 ----------------------------------------------------
    54 
    55   * Fixed translation selection when an unsupported locale is specified,
    56     choosing the first locale as the default (rather than exposing the values
    57     themselves as translations). Note that this is an unfortunate and subtle
    58     change which may affect application output - apologies are hereby offered!
    59 
    60 New in XSLTools 0.4.2 (Changes since XSLTools 0.4.1)
    61 ----------------------------------------------------
    62 
    63   * Added a content type check in the XSLFormsResource class, permitting
    64     non-form-based resources to access the raw request data, rather than have
    65     the data processed unsuccessfully and consequently discarded.
    66   * Added a script and a function to fix template namespaces after editing in
    67     a careless editor.
    68   * Changed libxml2mod and libxsltmod import details to try libxmlmods -
    69     suggested by Lucian Wischik for libxml2dom.
    70 
    71 New in XSLTools 0.4.1 (Changes since XSLTools 0.4)
    72 --------------------------------------------------
    73 
    74   * Made translations specified using the template:i18n annotation take
    75     priority over template:value annotations.
    76   * Added expression-based template:i18n annotations, and provided fallback
    77     output for such translations based on the value of the evaluated
    78     expression.
    79 
    80 New in XSLTools 0.4 (Changes since XSLTools 0.3.1)
    81 --------------------------------------------------
    82 
    83   * Changed the preparation of templates to produce rule-based output
    84     stylesheets, thus permitting recursive templates. This requires an extra
    85     expr-prefix annotation to be used in certain kinds of templates.
    86   * Added a recursive template example application.
    87   * Changed fragment production to use original template documents instead of
    88     output stylesheets.
    89   * Changed the in_page_resources attribute to provide the output identifier,
    90     thus changing the prepare_fragment method in Web resources so that only
    91     the fragment identifier needs to be supplied.
    92   * Added the XSLForms.Resources.WebResources.prepare_resources method for the
    93     preparation of initialiser and output stylesheets before an application is
    94     run.
    95   * Changed selectors to not automatically create elements in the form data
    96     document unless requested to do so. Introduced a Form.get_selector
    97     method in XSLForms.Fields.
    98   * Permitted the creation of hierarchies of elements in
    99     XSLForms.Utils.add_elements.
   100   * Introduced dynamic parameter evaluation for multiple-choice fields in
   101     order to support sources of multiple-choice values which reside in the
   102     form data document itself.
   103   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
   104     editors which strip namespace prefixes.
   105   * Fixed filesystem encoding issues in the Candidate example; fixed language
   106     preference access in the Configurator and VerySimple examples.
   107   * Changed the BaseHTTPRequestHandler version of the Candidate example to
   108     store data in a subdirectory of the current working directory, thus
   109     allowing the demonstration application to work after package installation.
   110 
   111 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
   112 --------------------------------------------------
   113 
   114   * Fixed copyright and licensing information.
   115 
   116 New in XSLTools 0.3 (Changes since XSLTools 0.2)
   117 ------------------------------------------------
   118 
   119   * Introduced copying of multiple-choice value element contents so that
   120     option element labels can differ from the underlying values.
   121   * Added internationalisation support, providing the template:i18n annotation
   122     and the template:i18n extension function.
   123   * Updated the documentation to cover the above new features.
   124   * Fixed non-GET/POST request method handling in WebResources.
   125   * Added the xslform_preparemacro.py script.
   126   * Added an experimental template:range extension function.
   127 
   128 New in XSLTools 0.2 (Changes since XSLTools 0.1)
   129 ------------------------------------------------
   130 
   131   * Made a new XSLTools package and moved XSLOutput into it.
   132   * Improved serialisation of transformation results so that output options
   133     are observed (in some cases, at least).
   134   * Fixed stylesheet and reference document paths so that libxslt should not
   135     now become confused by ambiguous relative paths.
   136   * Added expression parameters to XSLOutput.Processor so that in-document
   137     data can be used to, for example, initialise multiple-choice field values.
   138   * Added input/initialiser support so that input documents can be tidied or
   139     initialised using information from the template.
   140   * Added template:init for use with template:element in XSLForms to control
   141     element initialisation where necessary.
   142   * Added special high-level "macro" attributes (eg. template:attribute-field)
   143     which should make templates easier to write and maintain.
   144   * Added template:if to XSLForms, providing conditional output of annotated
   145     elements.
   146   * Added set_document to XSLForms.Fields.Form.
   147   * Added prepare_parameters to the XSLFormsResource class in the
   148     XSLForms.Resources.WebResources module.
   149   * Added element-path, url-encode and choice XSLForms extension functions.
   150   * Improved Unicode support in the XSLForms extension functions.
   151   * Changed in-page requests to contain proper POST data.
   152   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   153   * Updated the code to work with WebStack 1.0 changes and adopted the
   154     new-style WebStack demonstration mechanism.
   155   * Added XMLCalendar and XMLTable (to the XSLTools package).
   156   * Added a dictionary (or word lookup) example application.
   157   * Added a job candidate profile (or CV editor) example application.
   158   * Added a template attribute reference and an XSLFormsResource guide to the
   159     documentation.
   160   * Added Debian package support (specifically Ubuntu package support).
   161   * Added missing COPYING.txt file.
   162   * Renamed the scripts to avoid naming issues in system-wide installations.
   163   * Added a PyQt example based on the system configurator example, with the
   164     form prepared in Qt Designer. This example runs in PyQt and in a Web
   165     environment without any changes to the application code. In-page updates
   166     are currently not implemented in the Web version, however.
   167 
   168 Notes on In-Page Update Functionality
   169 -------------------------------------
   170 
   171 Special note #1: Konqueror seems in certain cases to remember replaced form
   172 content (when replaceChild is used to replace regions of the page which
   173 include form elements). This causes the browser to believe that more form
   174 fields exist on the page than actually do so, and subsequent form submissions
   175 thus include the values of such removed fields. A special hack is in place to
   176 disable form fields by changing their names, thus causing Konqueror to not
   177 associate such fields with the real, active fields; this hack does not seem to
   178 cause problems for Mozilla. This needs some investigation to determine in
   179 exactly which circumstances the problem arises.
   180 
   181 Special note #2: Konqueror also seems to crash if asked to find elements using
   182 an empty 'id' attribute string. This needs some investigation to see if it
   183 really is the getElementById call that causes the crash.
   184 
   185 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   186 the end of field values. Attempting to prune them before the request is sent
   187 fails with a function like the following:
   188 
   189 function fixValue(fieldValue) {
   190     if (fieldValue.length == 0) {
   191         return fieldValue;
   192     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   193         return fieldValue.substr(0, fieldValue.length - 1);
   194     } else {
   195         return fieldValue;
   196     }
   197 }
   198 
   199 This may be because it is the entire message that is terminated with the null
   200 character, and that this happens only upon sending the message. Consequently,
   201 some frameworks (notably mod_python) do not support in-page functionality when
   202 used from Konqueror.
   203 
   204 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   205 XMLHttpRequest in-page updates to function unless the URL used in the
   206 requestUpdate JavaScript function is compatible with the URL at which the
   207 browser finds the application. Currently, relative URLs are in use to avoid
   208 this issue of compatibility, but should an absolute URL be deduced using the
   209 WebStack API and then used, it may be possible that the values returned by
   210 that API do not match the actual addresses entered into the address bar of the
   211 browser.
   212 
   213 To check the behaviour of the applications, it is possible to view the
   214 document source of the pages served by applications and to verify that the
   215 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   216 a relative link or involve a URL similar to that which appears in the
   217 browser's address bar. In some environments, the use of 'localhost' addresses
   218 often confuses the browser and server; one workaround is to use real host
   219 names or addresses instead of 'localhost'.
   220 
   221 Choosing an element-path:
   222 
   223 When specifying the "context" of the in-page update, one must imagine which
   224 element the template fragment should operate within. If the template:id
   225 attribute marks a particular section, then the element-path should be a path
   226 to the applicable context element for that section in the complete template
   227 document. Note that if a template:element attribute appears on the same
   228 element as the template:id attribute then the element-path should refer to the
   229 element specified in the template:element attribute.
   230 
   231 Choosing where to put template:attribute, template:id and id:
   232 
   233 When specifying the extent of a template fragment, one must be sure not to put
   234 the template:id attribute on the same element as a template:attribute
   235 annotation; otherwise, the generated code will be improperly extracted as a
   236 fragment producing two versions of the element - one for when the specified
   237 attribute is present, and one for when it is not present. Generally,
   238 template:id and id can be placed on the same node, however.
   239 
   240 Stable element ordering and element-path:
   241 
   242 Within the element-path, the numbering of the elements will start at 1.
   243 Therefore it is vital to choose a region of the form data structure with the
   244 element-path which is isolated from surrounding elements whose positions would
   245 otherwise be dependent on a stable ordering of elements, and whose processing
   246 would be disrupted if some new elements suddenly appeared claiming the same
   247 positions in the document. For example:
   248 
   249   <item value="">         .../item$1/value
   250     <type value=""/>      .../item$1/type$1/value
   251     <comment value=""/>   .../item$1/comment$2/value
   252   </item>
   253 
   254   In-page update...
   255 
   256   <comment value=""/>     .../item$1/comment$1/value
   257 
   258 Notes on XSL
   259 ------------
   260 
   261 libxslt seems to be quite liberal on the definition of runtime parameters, in
   262 that there is no apparent need to explicitly declare the corresponding global
   263 variables in stylesheets. Whilst this is nice, we may eventually need to
   264 detect such variables and add them in the preparation process.
   265 
   266 Release Procedures
   267 ------------------
   268 
   269 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   270 attributes.
   271 Change the version number and package filename/directory in the documentation.
   272 Change code examples in the documentation if appropriate.
   273 Update the release notes (see above).
   274 Check the setup.py file and ensure that all package directories are mentioned.
   275 Check the release information in the PKG-INFO file and in the package
   276 changelog (and other files).
   277 Tag, export.
   278 Generate the example resources.
   279 Generate the API documentation.
   280 Remove generated .pyc files: rm `find . -name "*.pyc"`
   281 Archive, upload.
   282 Upload the introductory documentation.
   283 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   284 
   285 Generating the Example Resources
   286 --------------------------------
   287 
   288 In order to prepare the example resources, the prepare_demo.py script must be
   289 run as follows:
   290 
   291 python tools/prepare_demo.py
   292 
   293 This will ensure that all initialiser and output stylesheets are created and
   294 are thus installed by packages.
   295 
   296 Generating the API Documentation
   297 --------------------------------
   298 
   299 In order to prepare the API documentation, it is necessary to generate some
   300 Web pages from the Python source code. For this, the epydoc application must
   301 be available on your system. Then, inside the distribution directory, run the
   302 apidocs.sh tool script as follows:
   303 
   304 ./tools/apidocs.sh
   305 
   306 Some warnings may be generated by the script, but the result should be a new
   307 apidocs directory within the distribution directory.
   308 
   309 Making Packages
   310 ---------------
   311 
   312 To make Debian-based packages:
   313 
   314   1. Create new package directories under packages if necessary.
   315   2. Make a symbolic link in the distribution's root directory to keep the
   316      Debian tools happy:
   317 
   318      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   319 
   320   3. Run the package builder:
   321 
   322      dpkg-buildpackage -rfakeroot
   323 
   324   4. Locate and tidy up the packages in the parent directory of the
   325      distribution's root directory.