ifupdown2/ifupdown/template.py

   1 #!/usr/bin/python
   2 #
   3 # Copyright 2014 Cumulus Networks, Inc. All rights reserved.
   4 # Author: Roopa Prabhu, roopa@cumulusnetworks.com
   5 #
   6 # template --
   7 #    helper class to render templates
   8 #
   9
  10 import logging
  11 import traceback
  12 from utils import *
  13
  14 class templateEngine():
  15     """ provides template rendering methods """
  16
  17     def __init__(self, template_engine, template_lookuppath=None):
  18         self.logger = logging.getLogger('ifupdown.' +
  19                     self.__class__.__name__)
  20         self.tclass = None
  21         self.tclassargs = {}
  22         self.render = self._render_default
  23         if template_engine == 'mako':
  24             try:
  25                 self.tclass = utils.importName('mako.template', 'Template')
  26             except Exception, e:
  27                 self.logger.warn('unable to load template engine %s (%s)'
  28                         %(template_engine, str(e)))
  29                 pass
  30             if template_lookuppath:
  31                 try:
  32                     self.logger.debug('setting template lookuppath to %s'
  33                             %template_lookuppath)
  34                     lc = utils.importName('mako.lookup', 'TemplateLookup')
  35                     self.tclassargs['lookup'] = lc(
  36                                 directories=template_lookuppath.split(':'))
  37                 except Exception, e:
  38                     self.logger.warn('unable to set template lookup path' +
  39                                 ' %s (%s)' %(template_lookuppath, str(e)))
  40                     pass
  41             self.render = self._render_mako
  42         else:
  43             self.logger.info('skip template processing.., ' +
  44                     'template engine not found')
  45
  46     def _render_default(self, textdata):
  47         return textdata
  48
  49     def _render_mako(self, textdata):
  50         """ render textdata passed as argument using mako
  51
  52         Returns rendered textdata """
  53
  54         if not self.tclass:
  55             return textdata
  56         self.logger.info('template processing on interfaces file ...')
  57         t = self.tclass(text=textdata, output_encoding='utf-8',
  58                      lookup=self.tclassargs.get('lookup'))
  59         return t.render()