~loggerhead-team/loggerhead/trunk-rich

"TurboGears support for Zope Page Templates"

import StringIO

import logging

import pkg_resources

#from zope.pagetemplate.pagetemplatefile import PageTemplateFile

from simpletal import simpleTAL, simpleTALES

log = logging.getLogger("turbogears.zptsupport")

_zpt_cache = {}

def zpt(tfile):

    tinstance = _zpt_cache.get(tfile)

    if tinstance is None:

        tinstance = _zpt_cache[tfile] = TemplateWrapper(

            simpleTAL.compileXMLTemplate(open(tfile)), tfile)

    return tinstance

class TemplateWrapper(object):

    def __init__(self, template, filename):

        self.template = template

        self.filename = filename

    def expand(self, **info):

        context = simpleTALES.Context(allowPythonPath=1)

        for k, v in info.iteritems():

            context.addGlobal(k, v)

        s = StringIO.StringIO()

        self.template.expandInline(context, s)

        return s.getvalue()

    @property

    def macros(self):

        return self.template.macros

## class TGPageTemplateFile(PageTemplateFile):

##     def pt_getContext(self, args=(), options={}, **ignored):

##         namespace = super(TGPageTemplateFile, self).pt_getContext(

##             args, options, **ignored)

##         namespace.update(options)

##         return namespace

class TurboZpt(object):

    extension = "pt"

    def __init__(self, extra_vars_func=None):

        self.get_extra_vars = extra_vars_func

    def load_template(self, classname, loadingSite=False):

        """Searches for a template along the Python path.

        Template files must end in ".pt" and be in legitimate packages.

        Templates are automatically checked for changes and reloaded as

        neccessary.

        """

        divider = classname.rfind(".")

        if divider > -1:

            package = classname[0:divider]

            basename = classname[divider+1:]

        else:

            raise ValueError, "All templates must be in a package"

        tfile = pkg_resources.resource_filename(

            package, "%s.%s" % (basename, self.extension))

        return zpt(tfile)

    def render(self, info, format="html", fragment=False, template=None):

        """Renders data in the desired format.

        @param info: the data / context itself

        @type info: dict

        @para format: "html"

        @type format: "string"

        @para template: name of the template to use

        @type template: string

        """

        tinstance = self.load_template(template)

        log.debug("Applying template %s" % (tinstance.filename))

        data = dict()

        if self.get_extra_vars:

            data.update(self.get_extra_vars())

        data.update(info)

        return tinstance.expand(**data).encode('utf-8')