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 0.2.4
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 or later).
44 The example PyQt applications have been tested with PyQt 3.15.
45
46 New in XSLTools 0.2 (Changes since XSLTools 0.1)
47 ------------------------------------------------
48
49 * Made a new XSLTools package and moved XSLOutput into it.
50 * Improved serialisation of transformation results so that output options
51 are observed (in some cases, at least).
52 * Fixed stylesheet and reference document paths so that libxslt should not
53 now become confused by ambiguous relative paths.
54 * Added expression parameters to XSLOutput.Processor so that in-document
55 data can be used to, for example, initialise multiple-choice field values.
56 * Added input/initialiser support so that input documents can be tidied or
57 initialised using information from the template.
58 * Added template:init for use with template:element in XSLForms to control
59 element initialisation where necessary.
60 * Added special high-level "macro" attributes (eg. template:attribute-field)
61 which should make templates easier to write and maintain.
62 * Added template:if to XSLForms, providing conditional output of annotated
63 elements.
64 * Added set_document to XSLForms.Fields.Form.
65 * Added prepare_parameters to the XSLFormsResource class in the
66 XSLForms.Resources.WebResources module.
67 * Added element-path, url-encode and choice XSLForms extension functions.
68 * Improved Unicode support in the XSLForms extension functions.
69 * Changed in-page requests to contain proper POST data.
70 * Fixed checkbox and radiobutton value detection in XSLForms.js.
71 * Updated the code to work with WebStack 1.0 changes and adopted the
72 new-style WebStack demonstration mechanism.
73 * Added XMLCalendar and XMLTable (to the XSLTools package).
74 * Added a dictionary (or word lookup) example application.
75 * Added a job candidate profile (or CV editor) example application.
76 * Added a template attribute reference and an XSLFormsResource guide to the
77 documentation.
78 * Added Debian package support (specifically Ubuntu package support).
79 * Added missing COPYING.txt file.
80 * Renamed the scripts to avoid naming issues in system-wide installations.
81 * Added a PyQt example based on the system configurator example, with the
82 form prepared in Qt Designer. This example runs in PyQt and in a Web
83 environment without any changes to the application code. In-page updates
84 are currently not implemented in the Web version, however.
85
86 Notes on In-Page Update Functionality
87 -------------------------------------
88
89 Special note #1: Konqueror seems in certain cases to remember replaced form
90 content (when replaceChild is used to replace regions of the page which
91 include form elements). This causes the browser to believe that more form
92 fields exist on the page than actually do so, and subsequent form submissions
93 thus include the values of such removed fields. A special hack is in place to
94 disable form fields by changing their names, thus causing Konqueror to not
95 associate such fields with the real, active fields; this hack does not seem to
96 cause problems for Mozilla. This needs some investigation to determine in
97 exactly which circumstances the problem arises.
98
99 Special note #2: Konqueror also seems to crash if asked to find elements using
100 an empty 'id' attribute string. This needs some investigation to see if it
101 really is the getElementById call that causes the crash.
102
103 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
104 the end of field values. Attempting to prune them before the request is sent
105 fails with a function like the following:
106
107 function fixValue(fieldValue) {
108 if (fieldValue.length == 0) {
109 return fieldValue;
110 } else if (fieldValue[fieldValue.length - 1] == '\0') {
111 return fieldValue.substr(0, fieldValue.length - 1);
112 } else {
113 return fieldValue;
114 }
115 }
116
117 This may be because it is the entire message that is terminated with the null
118 character, and that this happens only upon sending the message. Consequently,
119 some frameworks (notably mod_python) do not support in-page functionality when
120 used from Konqueror.
121
122 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
123 XMLHttpRequest in-page updates to function unless the URL used in the
124 requestUpdate JavaScript function is compatible with the URL at which the
125 browser finds the application. Currently, relative URLs are in use to avoid
126 this issue of compatibility, but should an absolute URL be deduced using the
127 WebStack API and then used, it may be possible that the values returned by
128 that API do not match the actual addresses entered into the address bar of the
129 browser.
130
131 To check the behaviour of the applications, it is possible to view the
132 document source of the pages served by applications and to verify that the
133 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
134 a relative link or involve a URL similar to that which appears in the
135 browser's address bar. In some environments, the use of 'localhost' addresses
136 often confuses the browser and server; one workaround is to use real host
137 names or addresses instead of 'localhost'.
138
139 Choosing an element-path:
140
141 When specifying the "context" of the in-page update, one must imagine which
142 element the template fragment should operate within. If the template:id
143 attribute marks a particular section, then the element-path should be a path
144 to the applicable context element for that section in the complete template
145 document. Note that if a template:element attribute appears on the same
146 element as the template:id attribute then the element-path should refer to the
147 element specified in the template:element attribute.
148
149 Choosing where to put template:attribute, template:id and id:
150
151 When specifying the extent of a template fragment, one must be sure not to put
152 the template:id attribute on the same element as a template:attribute
153 annotation; otherwise, the generated code will be improperly extracted as a
154 fragment producing two versions of the element - one for when the specified
155 attribute is present, and one for when it is not present. Generally,
156 template:id and id can be placed on the same node, however.
157
158 Stable element ordering and element-path:
159
160 Within the element-path, the numbering of the elements will start at 1.
161 Therefore it is vital to choose a region of the form data structure with the
162 element-path which is isolated from surrounding elements whose positions would
163 otherwise be dependent on a stable ordering of elements, and whose processing
164 would be disrupted if some new elements suddenly appeared claiming the same
165 positions in the document. For example:
166
167 <item value=""> .../item$1/value
168 <type value=""/> .../item$1/type$1/value
169 <comment value=""/> .../item$1/comment$2/value
170 </item>
171
172 In-page update...
173
174 <comment value=""/> .../item$1/comment$1/value
175
176 Notes on XSL
177 ------------
178
179 libxslt seems to be quite liberal on the definition of runtime parameters, in
180 that there is no apparent need to explicitly declare the corresponding global
181 variables in stylesheets. Whilst this is nice, we may eventually need to
182 detect such variables and add them in the preparation process.
183
184 Release Procedures
185 ------------------
186
187 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
188 attributes.
189 Change the version number and package filename/directory in the documentation.
190 Change code examples in the documentation if appropriate.
191 Update the release notes (see above).
192 Check the setup.py file and ensure that all package directories are mentioned.
193 Check the release information in the PKG-INFO file and in the package
194 changelog (and other files).
195 Tag, export.
196 Generate the API documentation.
197 Remove generated .pyc files: rm `find . -name "*.pyc"`
198 Archive, upload.
199 Upload the introductory documentation.
200 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
201
202 Generating the API Documentation
203 --------------------------------
204
205 In order to prepare the API documentation, it is necessary to generate some
206 Web pages from the Python source code. For this, the epydoc application must
207 be available on your system. Then, inside the distribution directory, run the
208 apidocs.sh tool script as follows:
209
210 ./tools/apidocs.sh
211
212 Some warnings may be generated by the script, but the result should be a new
213 apidocs directory within the distribution directory.
214
215 Making Packages
216 ---------------
217
218 To make Debian-based packages:
219
220 1. Create new package directories under packages if necessary.
221 2. Make a symbolic link in the distribution's root directory to keep the
222 Debian tools happy:
223
224 ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
225
226 3. Run the package builder:
227
228 dpkg-buildpackage -rfakeroot
229
230 4. Locate and tidy up the packages in the parent directory of the
231 distribution's root directory.