/loggerhead/trunk

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335  USA

#

"""Support for Zope Page Templates using the simpletal library."""

import logging

import os

import pkg_resources

import re

import StringIO

from simpletal import simpleTAL, simpleTALES

_zpt_cache = {}

def zpt(tfile):

    tinstance = _zpt_cache.get(tfile)

    stat = os.stat(tfile)

    if tinstance is None or tinstance.stat != stat:

        text = open(tfile).read()

        text = re.sub(r'\s*\n\s*', '\n', text)

        text = re.sub(r'[ \t]+', ' ', text)

        tinstance = _zpt_cache[tfile] = TemplateWrapper(

            simpleTAL.compileXMLTemplate(text), tfile, stat)

    return tinstance

class TemplateWrapper(object):

    def __init__(self, template, filename, stat):

        self.template = template

        self.filename = filename

        self.stat = stat

    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()

    def expand_into(self, f, **info):

        context = simpleTALES.Context(allowPythonPath=1)

        for k, v in info.iteritems():

            context.addGlobal(k, v)

        self.template.expand(context, f, 'utf-8')

    @property

    def macros(self):

        return self.template.macros

def load_template(classname):

    """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, "pt"))

    return zpt(tfile)