Using TAL outside Zope with path expressions
Hi, I'm trying to use TAL (from Zope 2.7.0) outside the Zope context (== standalone program). I have cooked a small test case to illustrate where I got stuck. The problems are the following: 1) I could not use path expressions inside TAL repeat loops, something like "tal:content='itervar/someattr'" fails. - Apparently DummyEngine does not parses nor handles path expression inside evaluatePathOrVar(expr). It just checks if it belongs to self.locals or sefl.globals How does it work inside Zope ? Does it use a different Engine ? I failed to locate this in the Zope code, any pointers ? 2) I could not find how Zope handles 'repeat/itervar/odd' and simmilar constructions upon the repeat var. This also fails when I use TAL outside Zope. 3) I found some 'z:...' instead of 'tal:...' constructions inside the test cases. They are equivalent ? Is this documented somewhere ? TIA, Rod Senra rodsenra at gpr.com.br <code> from TAL.HTMLTALParser import HTMLTALParser from TAL.TALInterpreter import TALInterpreter from TAL.TALGenerator import TALGenerator from TAL.DummyEngine import DummyEngine context = { 'some_list':[{'href':'http://localhost','content':'bar1'}, {'href':'http://localhost','content':'bar2'}] } # This template works fine! templateOk = """" <html><body><ul> <li tal:repeat="foo some_list"> <a tal:attributes="href python:foo['href']" tal:content="python:foo['content']"> </a> </li> </ul></body></html> """ # This template below fails templateBug = """" <html><body><ul> <li tal:repeat="foo some_list"> <a tal:attributes="href foo/href" tal:content="foo/content"> </a> </li> </ul></body></html> """ def generateFile(template,context={},macros={}): eng = DummyEngine(macros) eng.locals.update(context) gen = TALGenerator(expressionCompiler=eng) parser = HTMLTALParser(gen) parser.parseString(template) program, macros = parser.getCode() stream = StringIO() interp = TALInterpreter(program, macros, eng, stream) interp() return stream.getvalue().strip() print generateFile(templateOk,context) print generateFile(templateBug,context) </code> --------------------------------------------------------------- <output> <html><body><ul> <li> <a href="http://localhost">bar1</a> </li> <li> <a href="http://localhost">bar2</a> </li> </ul></body></html> ... TAL.TALDefs.TALESError: unknown variable: 'foo/href' </output>
On Thu, 22 Jul 2004 18:26:19 -0300, Rodrigo Dias Arruda Senra <rodsenra@gpr.com.br> wrote:
I'm trying to use TAL (from Zope 2.7.0) outside the Zope context (== standalone program).
Cool!
I have cooked a small test case to illustrate where I got stuck. The problems are the following:
1) I could not use path expressions inside TAL repeat loops, something like "tal:content='itervar/someattr'" fails. - Apparently DummyEngine does not parses nor handles path expression inside evaluatePathOrVar(expr). It just checks if it belongs to self.locals or sefl.globals How does it work inside Zope ? Does it use a different Engine ? I failed to locate this in the Zope code, any pointers ?
DummyEngine is really only to support testing; it's not intended for general use. The engine used for page templates in Zope 2 is in Products.PageTemplates.TALES.
2) I could not find how Zope handles 'repeat/itervar/odd' and simmilar constructions upon the repeat var. This also fails when I use TAL outside Zope.
This should work once you switch engines.
3) I found some 'z:...' instead of 'tal:...' constructions inside the test cases. They are equivalent ? Is this documented somewhere ?
The namespace prefixes can be anything you want them to be[, XML style. The pre-defined namespace prefixes of tal:, metal:, and i18n: are only provided in HTML mode, but can be augmented using additional namespace declarations: <html xmlns:z="http://xml.zope.org/namespaces/tal"> The "z:" prefix is now equivalent to "tal:" </html> I urge you to consider using the Zope 3 implementation of page templates, which has a better separation of the components involved, and more documentation on how they work together. It's also the first to get maintenance attention these days. You may be particularly interested in the documentation in the zope.pagetemplate package. -Fred -- Fred L. Drake, Jr. <fdrake at gmail.com> Zope Corporation
On Fri, 23 Jul 2004 17:57:52 -0400 Fred Drake <fdrake@gmail.com> wrote:
I urge you to consider using the Zope 3 implementation of page templates, which has a better separation of the components involved, and more documentation on how they work together.
Indeed. Excelent advice. Thank you Fred, for your complete, precise and prompt response! For documentation's sake, I have transcripted my test case here. Therefore, Z3 newbies (like myself) can find this when looking for: 'using Zope Page Templates outside Zope context'. best regards, Rod Senra rsenra at acm.org ------------------------------------------------------------------ <source filename="test_ptZ3.py"> # This code was tested with Zope X3-3.0.0b1 from zope.pagetemplate.pagetemplate import PageTemplate context={'some_list':[{'href':'http://localhost','content':'bar1'}, {'href':'http://localhost','content':'bar2'}]} template1 = """" <html><body><ul> <li tal:repeat="foo some_list"> <a tal:attributes="href python:foo['href']" tal:content="python:foo['content']"> </a> </li> <li tal:repeat="foo some_list"> <a tal:attributes="href foo/href" tal:content="foo/content"> </a> </li> </ul></body></html> """ def generateFile(template,context): pt = PageTemplate() pt.write(template) return pt.pt_render(namespace=context) print generateFile(template1,context) </source>
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Fred Drake -
Rodrigo Dias Arruda Senra