XSLTools

README.txt

543:b7fffbec7d01
2008-06-21 Paul Boddie Added tag rel-0-4-2 for changeset 4d4a9c5345c0
     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
    40 libxml2                     Tested with 2.6.17
    41 libxslt                     Tested with 1.1.12
    42 
    43 The example Web applications require WebStack (release 1.1.2 or later).
    44 The example PyQt applications have been tested with PyQt 3.15.
    45 
    46 New in XSLTools 0.4.2 (Changes since XSLTools 0.4.1)
    47 ----------------------------------------------------
    48 
    49   * Added a content type check in the XSLFormsResource class, permitting
    50     non-form-based resources to access the raw request data, rather than have
    51     the data processed unsuccessfully and consequently discarded.
    52   * Added a script and a function to fix template namespaces after editing in
    53     a careless editor.
    54   * Changed libxml2mod and libxsltmod import details to try libxmlmods -
    55     suggested by Lucian Wischik for libxml2dom.
    56 
    57 New in XSLTools 0.4.1 (Changes since XSLTools 0.4)
    58 --------------------------------------------------
    59 
    60   * Made translations specified using the template:i18n annotation take
    61     priority over template:value annotations.
    62   * Added expression-based template:i18n annotations, and provided fallback
    63     output for such translations based on the value of the evaluated
    64     expression.
    65 
    66 New in XSLTools 0.4 (Changes since XSLTools 0.3.1)
    67 --------------------------------------------------
    68 
    69   * Changed the preparation of templates to produce rule-based output
    70     stylesheets, thus permitting recursive templates. This requires an extra
    71     expr-prefix annotation to be used in certain kinds of templates.
    72   * Added a recursive template example application.
    73   * Changed fragment production to use original template documents instead of
    74     output stylesheets.
    75   * Changed the in_page_resources attribute to provide the output identifier,
    76     thus changing the prepare_fragment method in Web resources so that only
    77     the fragment identifier needs to be supplied.
    78   * Added the XSLForms.Resources.WebResources.prepare_resources method for the
    79     preparation of initialiser and output stylesheets before an application is
    80     run.
    81   * Changed selectors to not automatically create elements in the form data
    82     document unless requested to do so. Introduced a Form.get_selector
    83     method in XSLForms.Fields.
    84   * Permitted the creation of hierarchies of elements in
    85     XSLForms.Utils.add_elements.
    86   * Introduced dynamic parameter evaluation for multiple-choice fields in
    87     order to support sources of multiple-choice values which reside in the
    88     form data document itself.
    89   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
    90     editors which strip namespace prefixes.
    91   * Fixed filesystem encoding issues in the Candidate example; fixed language
    92     preference access in the Configurator and VerySimple examples.
    93   * Changed the BaseHTTPRequestHandler version of the Candidate example to
    94     store data in a subdirectory of the current working directory, thus
    95     allowing the demonstration application to work after package installation.
    96 
    97 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
    98 --------------------------------------------------
    99 
   100   * Fixed copyright and licensing information.
   101 
   102 New in XSLTools 0.3 (Changes since XSLTools 0.2)
   103 ------------------------------------------------
   104 
   105   * Introduced copying of multiple-choice value element contents so that
   106     option element labels can differ from the underlying values.
   107   * Added internationalisation support, providing the template:i18n annotation
   108     and the template:i18n extension function.
   109   * Updated the documentation to cover the above new features.
   110   * Fixed non-GET/POST request method handling in WebResources.
   111   * Added the xslform_preparemacro.py script.
   112   * Added an experimental template:range extension function.
   113 
   114 New in XSLTools 0.2 (Changes since XSLTools 0.1)
   115 ------------------------------------------------
   116 
   117   * Made a new XSLTools package and moved XSLOutput into it.
   118   * Improved serialisation of transformation results so that output options
   119     are observed (in some cases, at least).
   120   * Fixed stylesheet and reference document paths so that libxslt should not
   121     now become confused by ambiguous relative paths.
   122   * Added expression parameters to XSLOutput.Processor so that in-document
   123     data can be used to, for example, initialise multiple-choice field values.
   124   * Added input/initialiser support so that input documents can be tidied or
   125     initialised using information from the template.
   126   * Added template:init for use with template:element in XSLForms to control
   127     element initialisation where necessary.
   128   * Added special high-level "macro" attributes (eg. template:attribute-field)
   129     which should make templates easier to write and maintain.
   130   * Added template:if to XSLForms, providing conditional output of annotated
   131     elements.
   132   * Added set_document to XSLForms.Fields.Form.
   133   * Added prepare_parameters to the XSLFormsResource class in the
   134     XSLForms.Resources.WebResources module.
   135   * Added element-path, url-encode and choice XSLForms extension functions.
   136   * Improved Unicode support in the XSLForms extension functions.
   137   * Changed in-page requests to contain proper POST data.
   138   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   139   * Updated the code to work with WebStack 1.0 changes and adopted the
   140     new-style WebStack demonstration mechanism.
   141   * Added XMLCalendar and XMLTable (to the XSLTools package).
   142   * Added a dictionary (or word lookup) example application.
   143   * Added a job candidate profile (or CV editor) example application.
   144   * Added a template attribute reference and an XSLFormsResource guide to the
   145     documentation.
   146   * Added Debian package support (specifically Ubuntu package support).
   147   * Added missing COPYING.txt file.
   148   * Renamed the scripts to avoid naming issues in system-wide installations.
   149   * Added a PyQt example based on the system configurator example, with the
   150     form prepared in Qt Designer. This example runs in PyQt and in a Web
   151     environment without any changes to the application code. In-page updates
   152     are currently not implemented in the Web version, however.
   153 
   154 Notes on In-Page Update Functionality
   155 -------------------------------------
   156 
   157 Special note #1: Konqueror seems in certain cases to remember replaced form
   158 content (when replaceChild is used to replace regions of the page which
   159 include form elements). This causes the browser to believe that more form
   160 fields exist on the page than actually do so, and subsequent form submissions
   161 thus include the values of such removed fields. A special hack is in place to
   162 disable form fields by changing their names, thus causing Konqueror to not
   163 associate such fields with the real, active fields; this hack does not seem to
   164 cause problems for Mozilla. This needs some investigation to determine in
   165 exactly which circumstances the problem arises.
   166 
   167 Special note #2: Konqueror also seems to crash if asked to find elements using
   168 an empty 'id' attribute string. This needs some investigation to see if it
   169 really is the getElementById call that causes the crash.
   170 
   171 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   172 the end of field values. Attempting to prune them before the request is sent
   173 fails with a function like the following:
   174 
   175 function fixValue(fieldValue) {
   176     if (fieldValue.length == 0) {
   177         return fieldValue;
   178     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   179         return fieldValue.substr(0, fieldValue.length - 1);
   180     } else {
   181         return fieldValue;
   182     }
   183 }
   184 
   185 This may be because it is the entire message that is terminated with the null
   186 character, and that this happens only upon sending the message. Consequently,
   187 some frameworks (notably mod_python) do not support in-page functionality when
   188 used from Konqueror.
   189 
   190 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   191 XMLHttpRequest in-page updates to function unless the URL used in the
   192 requestUpdate JavaScript function is compatible with the URL at which the
   193 browser finds the application. Currently, relative URLs are in use to avoid
   194 this issue of compatibility, but should an absolute URL be deduced using the
   195 WebStack API and then used, it may be possible that the values returned by
   196 that API do not match the actual addresses entered into the address bar of the
   197 browser.
   198 
   199 To check the behaviour of the applications, it is possible to view the
   200 document source of the pages served by applications and to verify that the
   201 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   202 a relative link or involve a URL similar to that which appears in the
   203 browser's address bar. In some environments, the use of 'localhost' addresses
   204 often confuses the browser and server; one workaround is to use real host
   205 names or addresses instead of 'localhost'.
   206 
   207 Choosing an element-path:
   208 
   209 When specifying the "context" of the in-page update, one must imagine which
   210 element the template fragment should operate within. If the template:id
   211 attribute marks a particular section, then the element-path should be a path
   212 to the applicable context element for that section in the complete template
   213 document. Note that if a template:element attribute appears on the same
   214 element as the template:id attribute then the element-path should refer to the
   215 element specified in the template:element attribute.
   216 
   217 Choosing where to put template:attribute, template:id and id:
   218 
   219 When specifying the extent of a template fragment, one must be sure not to put
   220 the template:id attribute on the same element as a template:attribute
   221 annotation; otherwise, the generated code will be improperly extracted as a
   222 fragment producing two versions of the element - one for when the specified
   223 attribute is present, and one for when it is not present. Generally,
   224 template:id and id can be placed on the same node, however.
   225 
   226 Stable element ordering and element-path:
   227 
   228 Within the element-path, the numbering of the elements will start at 1.
   229 Therefore it is vital to choose a region of the form data structure with the
   230 element-path which is isolated from surrounding elements whose positions would
   231 otherwise be dependent on a stable ordering of elements, and whose processing
   232 would be disrupted if some new elements suddenly appeared claiming the same
   233 positions in the document. For example:
   234 
   235   <item value="">         .../item$1/value
   236     <type value=""/>      .../item$1/type$1/value
   237     <comment value=""/>   .../item$1/comment$2/value
   238   </item>
   239 
   240   In-page update...
   241 
   242   <comment value=""/>     .../item$1/comment$1/value
   243 
   244 Notes on XSL
   245 ------------
   246 
   247 libxslt seems to be quite liberal on the definition of runtime parameters, in
   248 that there is no apparent need to explicitly declare the corresponding global
   249 variables in stylesheets. Whilst this is nice, we may eventually need to
   250 detect such variables and add them in the preparation process.
   251 
   252 Release Procedures
   253 ------------------
   254 
   255 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   256 attributes.
   257 Change the version number and package filename/directory in the documentation.
   258 Change code examples in the documentation if appropriate.
   259 Update the release notes (see above).
   260 Check the setup.py file and ensure that all package directories are mentioned.
   261 Check the release information in the PKG-INFO file and in the package
   262 changelog (and other files).
   263 Tag, export.
   264 Generate the example resources.
   265 Generate the API documentation.
   266 Remove generated .pyc files: rm `find . -name "*.pyc"`
   267 Archive, upload.
   268 Upload the introductory documentation.
   269 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   270 
   271 Generating the Example Resources
   272 --------------------------------
   273 
   274 In order to prepare the example resources, the prepare_demo.py script must be
   275 run as follows:
   276 
   277 python tools/prepare_demo.py
   278 
   279 This will ensure that all initialiser and output stylesheets are created and
   280 are thus installed by packages.
   281 
   282 Generating the API Documentation
   283 --------------------------------
   284 
   285 In order to prepare the API documentation, it is necessary to generate some
   286 Web pages from the Python source code. For this, the epydoc application must
   287 be available on your system. Then, inside the distribution directory, run the
   288 apidocs.sh tool script as follows:
   289 
   290 ./tools/apidocs.sh
   291 
   292 Some warnings may be generated by the script, but the result should be a new
   293 apidocs directory within the distribution directory.
   294 
   295 Making Packages
   296 ---------------
   297 
   298 To make Debian-based packages:
   299 
   300   1. Create new package directories under packages if necessary.
   301   2. Make a symbolic link in the distribution's root directory to keep the
   302      Debian tools happy:
   303 
   304      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   305 
   306   3. Run the package builder:
   307 
   308      dpkg-buildpackage -rfakeroot
   309 
   310   4. Locate and tidy up the packages in the parent directory of the
   311      distribution's root directory.