XSLTools

README.txt

490:727867e25309
2006-01-27 paulb [project @ 2006-01-27 17:00:27 by paulb] Added a recursive template example to the demonstration.
     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                  0.3.2
    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 (Changes since XSLTools 0.3.1)
    47 --------------------------------------------------
    48 
    49   * Changed the preparation of templates to produce rule-based output
    50     stylesheets, thus permitting recursive templates.
    51   * Changed fragment production to use original template documents instead of
    52     output stylesheets.
    53   * Changed selectors to not automatically create elements in the form data
    54     document unless requested to do so. Introduced a Form.get_selector
    55     method in XSLForms.Fields.
    56   * Introduced dynamic parameter evaluation for multiple-choice fields in
    57     order to support sources of multiple-choice values which reside in the
    58     form data document itself.
    59   * Added the FixNamespace.xsl stylesheet to correct documents saved by HTML
    60     editors which strip namespace prefixes.
    61 
    62 New in XSLTools 0.3.1 (Changes since XSLTools 0.3)
    63 --------------------------------------------------
    64 
    65   * Fixed copyright and licensing information.
    66 
    67 New in XSLTools 0.3 (Changes since XSLTools 0.2)
    68 ------------------------------------------------
    69 
    70   * Introduced copying of multiple-choice value element contents so that
    71     option element labels can differ from the underlying values.
    72   * Added internationalisation support, providing the template:i18n annotation
    73     and the template:i18n extension function.
    74   * Updated the documentation to cover the above new features.
    75   * Fixed non-GET/POST request method handling in WebResources.
    76   * Added the xslform_preparemacro.py script.
    77   * Added an experimental template:range extension function.
    78 
    79 New in XSLTools 0.2 (Changes since XSLTools 0.1)
    80 ------------------------------------------------
    81 
    82   * Made a new XSLTools package and moved XSLOutput into it.
    83   * Improved serialisation of transformation results so that output options
    84     are observed (in some cases, at least).
    85   * Fixed stylesheet and reference document paths so that libxslt should not
    86     now become confused by ambiguous relative paths.
    87   * Added expression parameters to XSLOutput.Processor so that in-document
    88     data can be used to, for example, initialise multiple-choice field values.
    89   * Added input/initialiser support so that input documents can be tidied or
    90     initialised using information from the template.
    91   * Added template:init for use with template:element in XSLForms to control
    92     element initialisation where necessary.
    93   * Added special high-level "macro" attributes (eg. template:attribute-field)
    94     which should make templates easier to write and maintain.
    95   * Added template:if to XSLForms, providing conditional output of annotated
    96     elements.
    97   * Added set_document to XSLForms.Fields.Form.
    98   * Added prepare_parameters to the XSLFormsResource class in the
    99     XSLForms.Resources.WebResources module.
   100   * Added element-path, url-encode and choice XSLForms extension functions.
   101   * Improved Unicode support in the XSLForms extension functions.
   102   * Changed in-page requests to contain proper POST data.
   103   * Fixed checkbox and radiobutton value detection in XSLForms.js.
   104   * Updated the code to work with WebStack 1.0 changes and adopted the
   105     new-style WebStack demonstration mechanism.
   106   * Added XMLCalendar and XMLTable (to the XSLTools package).
   107   * Added a dictionary (or word lookup) example application.
   108   * Added a job candidate profile (or CV editor) example application.
   109   * Added a template attribute reference and an XSLFormsResource guide to the
   110     documentation.
   111   * Added Debian package support (specifically Ubuntu package support).
   112   * Added missing COPYING.txt file.
   113   * Renamed the scripts to avoid naming issues in system-wide installations.
   114   * Added a PyQt example based on the system configurator example, with the
   115     form prepared in Qt Designer. This example runs in PyQt and in a Web
   116     environment without any changes to the application code. In-page updates
   117     are currently not implemented in the Web version, however.
   118 
   119 Notes on In-Page Update Functionality
   120 -------------------------------------
   121 
   122 Special note #1: Konqueror seems in certain cases to remember replaced form
   123 content (when replaceChild is used to replace regions of the page which
   124 include form elements). This causes the browser to believe that more form
   125 fields exist on the page than actually do so, and subsequent form submissions
   126 thus include the values of such removed fields. A special hack is in place to
   127 disable form fields by changing their names, thus causing Konqueror to not
   128 associate such fields with the real, active fields; this hack does not seem to
   129 cause problems for Mozilla. This needs some investigation to determine in
   130 exactly which circumstances the problem arises.
   131 
   132 Special note #2: Konqueror also seems to crash if asked to find elements using
   133 an empty 'id' attribute string. This needs some investigation to see if it
   134 really is the getElementById call that causes the crash.
   135 
   136 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
   137 the end of field values. Attempting to prune them before the request is sent
   138 fails with a function like the following:
   139 
   140 function fixValue(fieldValue) {
   141     if (fieldValue.length == 0) {
   142         return fieldValue;
   143     } else if (fieldValue[fieldValue.length - 1] == '\0') {
   144         return fieldValue.substr(0, fieldValue.length - 1);
   145     } else {
   146         return fieldValue;
   147     }
   148 }
   149 
   150 This may be because it is the entire message that is terminated with the null
   151 character, and that this happens only upon sending the message. Consequently,
   152 some frameworks (notably mod_python) do not support in-page functionality when
   153 used from Konqueror.
   154 
   155 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
   156 XMLHttpRequest in-page updates to function unless the URL used in the
   157 requestUpdate JavaScript function is compatible with the URL at which the
   158 browser finds the application. Currently, relative URLs are in use to avoid
   159 this issue of compatibility, but should an absolute URL be deduced using the
   160 WebStack API and then used, it may be possible that the values returned by
   161 that API do not match the actual addresses entered into the address bar of the
   162 browser.
   163 
   164 To check the behaviour of the applications, it is possible to view the
   165 document source of the pages served by applications and to verify that the
   166 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
   167 a relative link or involve a URL similar to that which appears in the
   168 browser's address bar. In some environments, the use of 'localhost' addresses
   169 often confuses the browser and server; one workaround is to use real host
   170 names or addresses instead of 'localhost'.
   171 
   172 Choosing an element-path:
   173 
   174 When specifying the "context" of the in-page update, one must imagine which
   175 element the template fragment should operate within. If the template:id
   176 attribute marks a particular section, then the element-path should be a path
   177 to the applicable context element for that section in the complete template
   178 document. Note that if a template:element attribute appears on the same
   179 element as the template:id attribute then the element-path should refer to the
   180 element specified in the template:element attribute.
   181 
   182 Choosing where to put template:attribute, template:id and id:
   183 
   184 When specifying the extent of a template fragment, one must be sure not to put
   185 the template:id attribute on the same element as a template:attribute
   186 annotation; otherwise, the generated code will be improperly extracted as a
   187 fragment producing two versions of the element - one for when the specified
   188 attribute is present, and one for when it is not present. Generally,
   189 template:id and id can be placed on the same node, however.
   190 
   191 Stable element ordering and element-path:
   192 
   193 Within the element-path, the numbering of the elements will start at 1.
   194 Therefore it is vital to choose a region of the form data structure with the
   195 element-path which is isolated from surrounding elements whose positions would
   196 otherwise be dependent on a stable ordering of elements, and whose processing
   197 would be disrupted if some new elements suddenly appeared claiming the same
   198 positions in the document. For example:
   199 
   200   <item value="">         .../item$1/value
   201     <type value=""/>      .../item$1/type$1/value
   202     <comment value=""/>   .../item$1/comment$2/value
   203   </item>
   204 
   205   In-page update...
   206 
   207   <comment value=""/>     .../item$1/comment$1/value
   208 
   209 Notes on XSL
   210 ------------
   211 
   212 libxslt seems to be quite liberal on the definition of runtime parameters, in
   213 that there is no apparent need to explicitly declare the corresponding global
   214 variables in stylesheets. Whilst this is nice, we may eventually need to
   215 detect such variables and add them in the preparation process.
   216 
   217 Release Procedures
   218 ------------------
   219 
   220 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
   221 attributes.
   222 Change the version number and package filename/directory in the documentation.
   223 Change code examples in the documentation if appropriate.
   224 Update the release notes (see above).
   225 Check the setup.py file and ensure that all package directories are mentioned.
   226 Check the release information in the PKG-INFO file and in the package
   227 changelog (and other files).
   228 Tag, export.
   229 Generate the API documentation.
   230 Remove generated .pyc files: rm `find . -name "*.pyc"`
   231 Archive, upload.
   232 Upload the introductory documentation.
   233 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
   234 
   235 Generating the API Documentation
   236 --------------------------------
   237 
   238 In order to prepare the API documentation, it is necessary to generate some
   239 Web pages from the Python source code. For this, the epydoc application must
   240 be available on your system. Then, inside the distribution directory, run the
   241 apidocs.sh tool script as follows:
   242 
   243 ./tools/apidocs.sh
   244 
   245 Some warnings may be generated by the script, but the result should be a new
   246 apidocs directory within the distribution directory.
   247 
   248 Making Packages
   249 ---------------
   250 
   251 To make Debian-based packages:
   252 
   253   1. Create new package directories under packages if necessary.
   254   2. Make a symbolic link in the distribution's root directory to keep the
   255      Debian tools happy:
   256 
   257      ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
   258 
   259   3. Run the package builder:
   260 
   261      dpkg-buildpackage -rfakeroot
   262 
   263   4. Locate and tidy up the packages in the parent directory of the
   264      distribution's root directory.