XSLTools

README.txt

525:3726d27b821e
2006-03-17 paulb [project @ 2006-03-17 18:07:09 by paulb] Reordered the substitution preferences, making template:i18n more important than template:value. Added expression support to template:i18n annotations, along with a means of controlling the fallback output in cases where no translations are found for a value.
     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 0.4.1 (Changes since XSLTools 0.4)
    47 --------------------------------------------------
    48 
    49   * Made translations specified using the template:i18n annotation take
    50     priority over template:value annotations.
    51   * Added expression-based template:i18n annotations, and provided fallback
    52     output for such translations based on the value of the evaluated
    53     expression.
    54 
    55 New in XSLTools 0.4 (Changes since XSLTools 0.3.1)
    56 --------------------------------------------------
    57 
    58   * Changed the preparation of templates to produce rule-based output
    59     stylesheets, thus permitting recursive templates. This requires an extra
    60     expr-prefix annotation to be used in certain kinds of templates.
    61   * Added a recursive template example application.
    62   * Changed fragment production to use original template documents instead of
    63     output stylesheets.
    64   * Changed the in_page_resources attribute to provide the output identifier,
    65     thus changing the prepare_fragment method in Web resources so that only
    66     the fragment identifier needs to be supplied.
    67   * Added the XSLForms.Resources.WebResources.prepare_resources method for the
    68     preparation of initialiser and output stylesheets before an application is
    69     run.
    70   * Changed selectors to not automatically create elements in the form data
    71     document unless requested to do so. Introduced a Form.get_selector
    72     method in XSLForms.Fields.
    73   * Permitted the creation of hierarchies of elements in
    74     XSLForms.Utils.add_elements.
    75   * Introduced dynamic parameter evaluation for multiple-choice fields in
    76     order to support sources of multiple-choice values which reside in the
    77     form data document itself.
    78   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
    79     editors which strip namespace prefixes.
    80   * Fixed filesystem encoding issues in the Candidate example; fixed language
    81     preference access in the Configurator and VerySimple examples.
    82   * Changed the BaseHTTPRequestHandler version of the Candidate example to
    83     store data in a subdirectory of the current working directory, thus
    84     allowing the demonstration application to work after package installation.
    85 
    86 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
    87 --------------------------------------------------
    88 
    89   * Fixed copyright and licensing information.
    90 
    91 New in XSLTools 0.3 (Changes since XSLTools 0.2)
    92 ------------------------------------------------
    93 
    94   * Introduced copying of multiple-choice value element contents so that
    95     option element labels can differ from the underlying values.
    96   * Added internationalisation support, providing the template:i18n annotation
    97     and the template:i18n extension function.
    98   * Updated the documentation to cover the above new features.
    99   * Fixed non-GET/POST request method handling in WebResources.
   100   * Added the xslform_preparemacro.py script.
   101   * Added an experimental template:range extension function.
   102 
   103 New in XSLTools 0.2 (Changes since XSLTools 0.1)
   104 ------------------------------------------------
   105 
   106   * Made a new XSLTools package and moved XSLOutput into it.
   107   * Improved serialisation of transformation results so that output options
   108     are observed (in some cases, at least).
   109   * Fixed stylesheet and reference document paths so that libxslt should not
   110     now become confused by ambiguous relative paths.
   111   * Added expression parameters to XSLOutput.Processor so that in-document
   112     data can be used to, for example, initialise multiple-choice field values.
   113   * Added input/initialiser support so that input documents can be tidied or
   114     initialised using information from the template.
   115   * Added template:init for use with template:element in XSLForms to control
   116     element initialisation where necessary.
   117   * Added special high-level "macro" attributes (eg. template:attribute-field)
   118     which should make templates easier to write and maintain.
   119   * Added template:if to XSLForms, providing conditional output of annotated
   120     elements.
   121   * Added set_document to XSLForms.Fields.Form.
   122   * Added prepare_parameters to the XSLFormsResource class in the
   123     XSLForms.Resources.WebResources module.
   124   * Added element-path, url-encode and choice XSLForms extension functions.
   125   * Improved Unicode support in the XSLForms extension functions.
   126   * Changed in-page requests to contain proper POST data.
   127   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   128   * Updated the code to work with WebStack 1.0 changes and adopted the
   129     new-style WebStack demonstration mechanism.
   130   * Added XMLCalendar and XMLTable (to the XSLTools package).
   131   * Added a dictionary (or word lookup) example application.
   132   * Added a job candidate profile (or CV editor) example application.
   133   * Added a template attribute reference and an XSLFormsResource guide to the
   134     documentation.
   135   * Added Debian package support (specifically Ubuntu package support).
   136   * Added missing COPYING.txt file.
   137   * Renamed the scripts to avoid naming issues in system-wide installations.
   138   * Added a PyQt example based on the system configurator example, with the
   139     form prepared in Qt Designer. This example runs in PyQt and in a Web
   140     environment without any changes to the application code. In-page updates
   141     are currently not implemented in the Web version, however.
   142 
   143 Notes on In-Page Update Functionality
   144 -------------------------------------
   145 
   146 Special note #1: Konqueror seems in certain cases to remember replaced form
   147 content (when replaceChild is used to replace regions of the page which
   148 include form elements). This causes the browser to believe that more form
   149 fields exist on the page than actually do so, and subsequent form submissions
   150 thus include the values of such removed fields. A special hack is in place to
   151 disable form fields by changing their names, thus causing Konqueror to not
   152 associate such fields with the real, active fields; this hack does not seem to
   153 cause problems for Mozilla. This needs some investigation to determine in
   154 exactly which circumstances the problem arises.
   155 
   156 Special note #2: Konqueror also seems to crash if asked to find elements using
   157 an empty 'id' attribute string. This needs some investigation to see if it
   158 really is the getElementById call that causes the crash.
   159 
   160 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   161 the end of field values. Attempting to prune them before the request is sent
   162 fails with a function like the following:
   163 
   164 function fixValue(fieldValue) {
   165     if (fieldValue.length == 0) {
   166         return fieldValue;
   167     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   168         return fieldValue.substr(0, fieldValue.length - 1);
   169     } else {
   170         return fieldValue;
   171     }
   172 }
   173 
   174 This may be because it is the entire message that is terminated with the null
   175 character, and that this happens only upon sending the message. Consequently,
   176 some frameworks (notably mod_python) do not support in-page functionality when
   177 used from Konqueror.
   178 
   179 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   180 XMLHttpRequest in-page updates to function unless the URL used in the
   181 requestUpdate JavaScript function is compatible with the URL at which the
   182 browser finds the application. Currently, relative URLs are in use to avoid
   183 this issue of compatibility, but should an absolute URL be deduced using the
   184 WebStack API and then used, it may be possible that the values returned by
   185 that API do not match the actual addresses entered into the address bar of the
   186 browser.
   187 
   188 To check the behaviour of the applications, it is possible to view the
   189 document source of the pages served by applications and to verify that the
   190 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   191 a relative link or involve a URL similar to that which appears in the
   192 browser's address bar. In some environments, the use of 'localhost' addresses
   193 often confuses the browser and server; one workaround is to use real host
   194 names or addresses instead of 'localhost'.
   195 
   196 Choosing an element-path:
   197 
   198 When specifying the "context" of the in-page update, one must imagine which
   199 element the template fragment should operate within. If the template:id
   200 attribute marks a particular section, then the element-path should be a path
   201 to the applicable context element for that section in the complete template
   202 document. Note that if a template:element attribute appears on the same
   203 element as the template:id attribute then the element-path should refer to the
   204 element specified in the template:element attribute.
   205 
   206 Choosing where to put template:attribute, template:id and id:
   207 
   208 When specifying the extent of a template fragment, one must be sure not to put
   209 the template:id attribute on the same element as a template:attribute
   210 annotation; otherwise, the generated code will be improperly extracted as a
   211 fragment producing two versions of the element - one for when the specified
   212 attribute is present, and one for when it is not present. Generally,
   213 template:id and id can be placed on the same node, however.
   214 
   215 Stable element ordering and element-path:
   216 
   217 Within the element-path, the numbering of the elements will start at 1.
   218 Therefore it is vital to choose a region of the form data structure with the
   219 element-path which is isolated from surrounding elements whose positions would
   220 otherwise be dependent on a stable ordering of elements, and whose processing
   221 would be disrupted if some new elements suddenly appeared claiming the same
   222 positions in the document. For example:
   223 
   224   <item value="">         .../item$1/value
   225     <type value=""/>      .../item$1/type$1/value
   226     <comment value=""/>   .../item$1/comment$2/value
   227   </item>
   228 
   229   In-page update...
   230 
   231   <comment value=""/>     .../item$1/comment$1/value
   232 
   233 Notes on XSL
   234 ------------
   235 
   236 libxslt seems to be quite liberal on the definition of runtime parameters, in
   237 that there is no apparent need to explicitly declare the corresponding global
   238 variables in stylesheets. Whilst this is nice, we may eventually need to
   239 detect such variables and add them in the preparation process.
   240 
   241 Release Procedures
   242 ------------------
   243 
   244 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   245 attributes.
   246 Change the version number and package filename/directory in the documentation.
   247 Change code examples in the documentation if appropriate.
   248 Update the release notes (see above).
   249 Check the setup.py file and ensure that all package directories are mentioned.
   250 Check the release information in the PKG-INFO file and in the package
   251 changelog (and other files).
   252 Tag, export.
   253 Generate the example resources.
   254 Generate the API documentation.
   255 Remove generated .pyc files: rm `find . -name "*.pyc"`
   256 Archive, upload.
   257 Upload the introductory documentation.
   258 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   259 
   260 Generating the Example Resources
   261 --------------------------------
   262 
   263 In order to prepare the example resources, the prepare_demo.py script must be
   264 run as follows:
   265 
   266 python tools/prepare_demo.py
   267 
   268 This will ensure that all initialiser and output stylesheets are created and
   269 are thus installed by packages.
   270 
   271 Generating the API Documentation
   272 --------------------------------
   273 
   274 In order to prepare the API documentation, it is necessary to generate some
   275 Web pages from the Python source code. For this, the epydoc application must
   276 be available on your system. Then, inside the distribution directory, run the
   277 apidocs.sh tool script as follows:
   278 
   279 ./tools/apidocs.sh
   280 
   281 Some warnings may be generated by the script, but the result should be a new
   282 apidocs directory within the distribution directory.
   283 
   284 Making Packages
   285 ---------------
   286 
   287 To make Debian-based packages:
   288 
   289   1. Create new package directories under packages if necessary.
   290   2. Make a symbolic link in the distribution's root directory to keep the
   291      Debian tools happy:
   292 
   293      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   294 
   295   3. Run the package builder:
   296 
   297      dpkg-buildpackage -rfakeroot
   298 
   299   4. Locate and tidy up the packages in the parent directory of the
   300      distribution's root directory.