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