XSLTools

README.txt

578:06fa14a9ac8a
2007-06-01 paulb [project @ 2007-06-01 23:42:45 by paulb] Updated release notes and dependencies.
     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 1.2.3 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 
    54 New in XSLTools 0.4.4 (Changes since XSLTools 0.4.3)
    55 ----------------------------------------------------
    56 
    57   * Fixed translation selection for the template:i18n annotation attribute,
    58     not just for the template:i18n extension function - more apologies for
    59     resulting output changes!
    60   * Improved the template fixing stylesheet and added some documentation for
    61     the script and the related expr-prefix attribute.
    62   * Introduced WebStack 1.2.2 EncodingSelector and encoding changes.
    63   * Added docstring and return value for the write_month_to_document function
    64     in XSLTools.XMLCalendar.
    65 
    66 New in XSLTools 0.4.3 (Changes since XSLTools 0.4.2)
    67 ----------------------------------------------------
    68 
    69   * Fixed translation selection when an unsupported locale is specified,
    70     choosing the first locale as the default (rather than exposing the values
    71     themselves as translations). Note that this is an unfortunate and subtle
    72     change which may affect application output - apologies are hereby offered!
    73 
    74 New in XSLTools 0.4.2 (Changes since XSLTools 0.4.1)
    75 ----------------------------------------------------
    76 
    77   * Added a content type check in the XSLFormsResource class, permitting
    78     non-form-based resources to access the raw request data, rather than have
    79     the data processed unsuccessfully and consequently discarded.
    80   * Added a script and a function to fix template namespaces after editing in
    81     a careless editor.
    82   * Changed libxml2mod and libxsltmod import details to try libxmlmods -
    83     suggested by Lucian Wischik for libxml2dom.
    84 
    85 New in XSLTools 0.4.1 (Changes since XSLTools 0.4)
    86 --------------------------------------------------
    87 
    88   * Made translations specified using the template:i18n annotation take
    89     priority over template:value annotations.
    90   * Added expression-based template:i18n annotations, and provided fallback
    91     output for such translations based on the value of the evaluated
    92     expression.
    93 
    94 New in XSLTools 0.4 (Changes since XSLTools 0.3.1)
    95 --------------------------------------------------
    96 
    97   * Changed the preparation of templates to produce rule-based output
    98     stylesheets, thus permitting recursive templates. This requires an extra
    99     expr-prefix annotation to be used in certain kinds of templates.
   100   * Added a recursive template example application.
   101   * Changed fragment production to use original template documents instead of
   102     output stylesheets.
   103   * Changed the in_page_resources attribute to provide the output identifier,
   104     thus changing the prepare_fragment method in Web resources so that only
   105     the fragment identifier needs to be supplied.
   106   * Added the XSLForms.Resources.WebResources.prepare_resources method for the
   107     preparation of initialiser and output stylesheets before an application is
   108     run.
   109   * Changed selectors to not automatically create elements in the form data
   110     document unless requested to do so. Introduced a Form.get_selector
   111     method in XSLForms.Fields.
   112   * Permitted the creation of hierarchies of elements in
   113     XSLForms.Utils.add_elements.
   114   * Introduced dynamic parameter evaluation for multiple-choice fields in
   115     order to support sources of multiple-choice values which reside in the
   116     form data document itself.
   117   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
   118     editors which strip namespace prefixes.
   119   * Fixed filesystem encoding issues in the Candidate example; fixed language
   120     preference access in the Configurator and VerySimple examples.
   121   * Changed the BaseHTTPRequestHandler version of the Candidate example to
   122     store data in a subdirectory of the current working directory, thus
   123     allowing the demonstration application to work after package installation.
   124 
   125 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
   126 --------------------------------------------------
   127 
   128   * Fixed copyright and licensing information.
   129 
   130 New in XSLTools 0.3 (Changes since XSLTools 0.2)
   131 ------------------------------------------------
   132 
   133   * Introduced copying of multiple-choice value element contents so that
   134     option element labels can differ from the underlying values.
   135   * Added internationalisation support, providing the template:i18n annotation
   136     and the template:i18n extension function.
   137   * Updated the documentation to cover the above new features.
   138   * Fixed non-GET/POST request method handling in WebResources.
   139   * Added the xslform_preparemacro.py script.
   140   * Added an experimental template:range extension function.
   141 
   142 New in XSLTools 0.2 (Changes since XSLTools 0.1)
   143 ------------------------------------------------
   144 
   145   * Made a new XSLTools package and moved XSLOutput into it.
   146   * Improved serialisation of transformation results so that output options
   147     are observed (in some cases, at least).
   148   * Fixed stylesheet and reference document paths so that libxslt should not
   149     now become confused by ambiguous relative paths.
   150   * Added expression parameters to XSLOutput.Processor so that in-document
   151     data can be used to, for example, initialise multiple-choice field values.
   152   * Added input/initialiser support so that input documents can be tidied or
   153     initialised using information from the template.
   154   * Added template:init for use with template:element in XSLForms to control
   155     element initialisation where necessary.
   156   * Added special high-level "macro" attributes (eg. template:attribute-field)
   157     which should make templates easier to write and maintain.
   158   * Added template:if to XSLForms, providing conditional output of annotated
   159     elements.
   160   * Added set_document to XSLForms.Fields.Form.
   161   * Added prepare_parameters to the XSLFormsResource class in the
   162     XSLForms.Resources.WebResources module.
   163   * Added element-path, url-encode and choice XSLForms extension functions.
   164   * Improved Unicode support in the XSLForms extension functions.
   165   * Changed in-page requests to contain proper POST data.
   166   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   167   * Updated the code to work with WebStack 1.0 changes and adopted the
   168     new-style WebStack demonstration mechanism.
   169   * Added XMLCalendar and XMLTable (to the XSLTools package).
   170   * Added a dictionary (or word lookup) example application.
   171   * Added a job candidate profile (or CV editor) example application.
   172   * Added a template attribute reference and an XSLFormsResource guide to the
   173     documentation.
   174   * Added Debian package support (specifically Ubuntu package support).
   175   * Added missing COPYING.txt file.
   176   * Renamed the scripts to avoid naming issues in system-wide installations.
   177   * Added a PyQt example based on the system configurator example, with the
   178     form prepared in Qt Designer. This example runs in PyQt and in a Web
   179     environment without any changes to the application code. In-page updates
   180     are currently not implemented in the Web version, however.
   181 
   182 Notes on In-Page Update Functionality
   183 -------------------------------------
   184 
   185 Special note #1: Konqueror seems in certain cases to remember replaced form
   186 content (when replaceChild is used to replace regions of the page which
   187 include form elements). This causes the browser to believe that more form
   188 fields exist on the page than actually do so, and subsequent form submissions
   189 thus include the values of such removed fields. A special hack is in place to
   190 disable form fields by changing their names, thus causing Konqueror to not
   191 associate such fields with the real, active fields; this hack does not seem to
   192 cause problems for Mozilla. This needs some investigation to determine in
   193 exactly which circumstances the problem arises.
   194 
   195 Special note #2: Konqueror also seems to crash if asked to find elements using
   196 an empty 'id' attribute string. This needs some investigation to see if it
   197 really is the getElementById call that causes the crash.
   198 
   199 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   200 the end of field values. Attempting to prune them before the request is sent
   201 fails with a function like the following:
   202 
   203 function fixValue(fieldValue) {
   204     if (fieldValue.length == 0) {
   205         return fieldValue;
   206     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   207         return fieldValue.substr(0, fieldValue.length - 1);
   208     } else {
   209         return fieldValue;
   210     }
   211 }
   212 
   213 This may be because it is the entire message that is terminated with the null
   214 character, and that this happens only upon sending the message. Consequently,
   215 some frameworks (notably mod_python) do not support in-page functionality when
   216 used from Konqueror.
   217 
   218 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   219 XMLHttpRequest in-page updates to function unless the URL used in the
   220 requestUpdate JavaScript function is compatible with the URL at which the
   221 browser finds the application. Currently, relative URLs are in use to avoid
   222 this issue of compatibility, but should an absolute URL be deduced using the
   223 WebStack API and then used, it may be possible that the values returned by
   224 that API do not match the actual addresses entered into the address bar of the
   225 browser.
   226 
   227 To check the behaviour of the applications, it is possible to view the
   228 document source of the pages served by applications and to verify that the
   229 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   230 a relative link or involve a URL similar to that which appears in the
   231 browser's address bar. In some environments, the use of 'localhost' addresses
   232 often confuses the browser and server; one workaround is to use real host
   233 names or addresses instead of 'localhost'.
   234 
   235 Choosing an element-path:
   236 
   237 When specifying the "context" of the in-page update, one must imagine which
   238 element the template fragment should operate within. If the template:id
   239 attribute marks a particular section, then the element-path should be a path
   240 to the applicable context element for that section in the complete template
   241 document. Note that if a template:element attribute appears on the same
   242 element as the template:id attribute then the element-path should refer to the
   243 element specified in the template:element attribute.
   244 
   245 Choosing where to put template:attribute, template:id and id:
   246 
   247 When specifying the extent of a template fragment, one must be sure not to put
   248 the template:id attribute on the same element as a template:attribute
   249 annotation; otherwise, the generated code will be improperly extracted as a
   250 fragment producing two versions of the element - one for when the specified
   251 attribute is present, and one for when it is not present. Generally,
   252 template:id and id can be placed on the same node, however.
   253 
   254 Stable element ordering and element-path:
   255 
   256 Within the element-path, the numbering of the elements will start at 1.
   257 Therefore it is vital to choose a region of the form data structure with the
   258 element-path which is isolated from surrounding elements whose positions would
   259 otherwise be dependent on a stable ordering of elements, and whose processing
   260 would be disrupted if some new elements suddenly appeared claiming the same
   261 positions in the document. For example:
   262 
   263   <item value="">         .../item$1/value
   264     <type value=""/>      .../item$1/type$1/value
   265     <comment value=""/>   .../item$1/comment$2/value
   266   </item>
   267 
   268   In-page update...
   269 
   270   <comment value=""/>     .../item$1/comment$1/value
   271 
   272 Notes on XSL
   273 ------------
   274 
   275 libxslt seems to be quite liberal on the definition of runtime parameters, in
   276 that there is no apparent need to explicitly declare the corresponding global
   277 variables in stylesheets. Whilst this is nice, we may eventually need to
   278 detect such variables and add them in the preparation process.
   279 
   280 Release Procedures
   281 ------------------
   282 
   283 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   284 attributes.
   285 Change the version number and package filename/directory in the documentation.
   286 Change code examples in the documentation if appropriate.
   287 Update the release notes (see above).
   288 Check the setup.py file and ensure that all package directories are mentioned.
   289 Check the release information in the PKG-INFO file and in the package
   290 changelog (and other files).
   291 Tag, export.
   292 Generate the example resources.
   293 Generate the API documentation.
   294 Remove generated .pyc files: rm `find . -name "*.pyc"`
   295 Archive, upload.
   296 Upload the introductory documentation.
   297 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   298 
   299 Generating the Example Resources
   300 --------------------------------
   301 
   302 In order to prepare the example resources, the prepare_demo.py script must be
   303 run as follows:
   304 
   305 python tools/prepare_demo.py
   306 
   307 This will ensure that all initialiser and output stylesheets are created and
   308 are thus installed by packages.
   309 
   310 Generating the API Documentation
   311 --------------------------------
   312 
   313 In order to prepare the API documentation, it is necessary to generate some
   314 Web pages from the Python source code. For this, the epydoc application must
   315 be available on your system. Then, inside the distribution directory, run the
   316 apidocs.sh tool script as follows:
   317 
   318 ./tools/apidocs.sh
   319 
   320 Some warnings may be generated by the script, but the result should be a new
   321 apidocs directory within the distribution directory.
   322 
   323 Making Packages
   324 ---------------
   325 
   326 To make Debian-based packages:
   327 
   328   1. Create new package directories under packages if necessary.
   329   2. Make a symbolic link in the distribution's root directory to keep the
   330      Debian tools happy:
   331 
   332      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   333 
   334   3. Run the package builder:
   335 
   336      dpkg-buildpackage -rfakeroot
   337 
   338   4. Locate and tidy up the packages in the parent directory of the
   339      distribution's root directory.