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 0.2.3
40 libxml2 Tested with 2.6.17
41 libxslt Tested with 1.1.12
42
43 The example Web applications require WebStack (release 1.0 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 XSLForms.Resources.XSLFormsResource.
66 * Added element-path and url-encode XSLForms extension functions.
67 * Improved Unicode support in the XSLForms extension functions.
68 * Changed in-page requests to contain proper POST data.
69 * Updated the code to work with WebStack 1.0 changes and adopted the
70 new-style WebStack demonstration mechanism.
71 * Added XMLCalendar and XMLTable (to the XSLTools package).
72 * Added a dictionary (or word lookup) example application.
73 * Added a job candidate profile (or CV editor) example application.
74 * Added a template attribute reference and an XSLFormsResource guide to the
75 documentation.
76 * Added Debian package support (specifically Ubuntu package support).
77 * Added missing COPYING.txt file.
78 * Renamed the scripts to avoid naming issues in system-wide installations.
79 * Added a PyQt example based on the system configurator example, with the
80 form prepared in Qt Designer. This example runs in PyQt and in a Web
81 environment without any changes to the application code. In-page updates
82 are currently not implemented in the Web version, however.
83
84 Notes on In-Page Update Functionality
85 -------------------------------------
86
87 Special note #1: Konqueror seems in certain cases to remember replaced form
88 content (when replaceChild is used to replace regions of the page which
89 include form elements). This causes the browser to believe that more form
90 fields exist on the page than actually do so, and subsequent form submissions
91 thus include the values of such removed fields. A special hack is in place to
92 disable form fields by changing their names, thus causing Konqueror to not
93 associate such fields with the real, active fields; this hack does not seem to
94 cause problems for Mozilla. This needs some investigation to determine in
95 exactly which circumstances the problem arises.
96
97 Special note #2: Konqueror also seems to crash if asked to find elements using
98 an empty 'id' attribute string. This needs some investigation to see if it
99 really is the getElementById call that causes the crash.
100
101 Special note #3: Konqueror's XMLHttpRequest seems to append null characters to
102 the end of field values. Attempting to prune them before the request is sent
103 fails with a function like the following:
104
105 function fixValue(fieldValue) {
106 if (fieldValue.length == 0) {
107 return fieldValue;
108 } else if (fieldValue[fieldValue.length - 1] == '\0') {
109 return fieldValue.substr(0, fieldValue.length - 1);
110 } else {
111 return fieldValue;
112 }
113 }
114
115 This may be because it is the entire message that is terminated with the null
116 character, and that this happens only upon sending the message. Consequently,
117 some frameworks (notably mod_python) do not support in-page functionality when
118 used from Konqueror.
119
120 Various browsers (eg. Mozilla/Firefox, Konqueror) will not allow the
121 XMLHttpRequest in-page updates to function unless the URL used in the
122 requestUpdate JavaScript function is compatible with the URL at which the
123 browser finds the application. Currently, relative URLs are in use to avoid
124 this issue of compatibility, but should an absolute URL be deduced using the
125 WebStack API and then used, it may be possible that the values returned by
126 that API do not match the actual addresses entered into the address bar of the
127 browser.
128
129 To check the behaviour of the applications, it is possible to view the
130 document source of the pages served by applications and to verify that the
131 URLs mentioned in the JavaScript function calls (to 'requestUpdate') either be
132 a relative link or involve a URL similar to that which appears in the
133 browser's address bar. In some environments, the use of 'localhost' addresses
134 often confuses the browser and server; one workaround is to use real host
135 names or addresses instead of 'localhost'.
136
137 Choosing an element-path:
138
139 When specifying the "context" of the in-page update, one must imagine which
140 element the template fragment should operate within. If the template:id
141 attribute marks a particular section, then the element-path should be a path
142 to the applicable context element for that section in the complete template
143 document. Note that if a template:element attribute appears on the same
144 element as the template:id attribute then the element-path should refer to the
145 element specified in the template:element attribute.
146
147 Choosing where to put template:attribute, template:id and id:
148
149 When specifying the extent of a template fragment, one must be sure not to put
150 the template:id attribute on the same element as a template:attribute
151 annotation; otherwise, the generated code will be improperly extracted as a
152 fragment producing two versions of the element - one for when the specified
153 attribute is present, and one for when it is not present. Generally,
154 template:id and id can be placed on the same node, however.
155
156 Stable element ordering and element-path:
157
158 Within the element-path, the numbering of the elements will start at 1.
159 Therefore it is vital to choose a region of the form data structure with the
160 element-path which is isolated from surrounding elements whose positions would
161 otherwise be dependent on a stable ordering of elements, and whose processing
162 would be disrupted if some new elements suddenly appeared claiming the same
163 positions in the document. For example:
164
165 <item value=""> .../item$1/value
166 <type value=""/> .../item$1/type$1/value
167 <comment value=""/> .../item$1/comment$2/value
168 </item>
169
170 In-page update...
171
172 <comment value=""/> .../item$1/comment$1/value
173
174 Notes on XSL
175 ------------
176
177 libxslt seems to be quite liberal on the definition of runtime parameters, in
178 that there is no apparent need to explicitly declare the corresponding global
179 variables in stylesheets. Whilst this is nice, we may eventually need to
180 detect such variables and add them in the preparation process.
181
182 Release Procedures
183 ------------------
184
185 Update the XSLTools/__init__.py and XSLForms/__init__.py __version__
186 attributes.
187 Change the version number and package filename/directory in the documentation.
188 Change code examples in the documentation if appropriate.
189 Update the release notes (see above).
190 Check the setup.py file and ensure that all package directories are mentioned.
191 Check the release information in the PKG-INFO file and in the package
192 changelog (and other files).
193 Tag, export.
194 Generate the API documentation.
195 Remove generated .pyc files: rm `find . -name "*.pyc"`
196 Archive, upload.
197 Upload the introductory documentation.
198 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
199
200 Generating the API Documentation
201 --------------------------------
202
203 In order to prepare the API documentation, it is necessary to generate some
204 Web pages from the Python source code. For this, the epydoc application must
205 be available on your system. Then, inside the distribution directory, run the
206 apidocs.sh tool script as follows:
207
208 ./tools/apidocs.sh
209
210 Some warnings may be generated by the script, but the result should be a new
211 apidocs directory within the distribution directory.
212
213 Making Packages
214 ---------------
215
216 To make Debian-based packages:
217
218 1. Create new package directories under packages if necessary.
219 2. Make a symbolic link in the distribution's root directory to keep the
220 Debian tools happy:
221
222 ln -s packages/ubuntu-hoary/python2.4-xsltools/debian/
223
224 3. Run the package builder:
225
226 dpkg-buildpackage -rfakeroot
227
228 4. Locate and tidy up the packages in the parent directory of the
229 distribution's root directory.