ext/inlinegettext.py

   1 # -*- coding: utf-8 -*-
   2 """
   3     Inline Gettext
   4     ~~~~~~~~~~~~~~
   5
   6     An example extension for Jinja2 that supports inline gettext calls.
   7     Requires the i18n extension to be loaded.
   8
   9     :copyright: (c) 2009 by the Jinja Team.
  10     :license: BSD.
  11 """
  12 import re
  13 from jinja2.ext import Extension
  14 from jinja2.lexer import Token, count_newlines
  15 from jinja2.exceptions import TemplateSyntaxError
  16
  17
  18 _outside_re = re.compile(r'\\?(gettext|_)\(')
  19 _inside_re = re.compile(r'\\?[()]')
  20
  21
  22 class InlineGettext(Extension):
  23     """This extension implements support for inline gettext blocks::
  24
  25         <h1>_(Welcome)</h1>
  26         <p>_(This is a paragraph)</p>
  27
  28     Requires the i18n extension to be loaded and configured.
  29     """
  30
  31     def filter_stream(self, stream):
  32         paren_stack = 0
  33
  34         for token in stream:
  35             if token.type is not 'data':
  36                 yield token
  37                 continue
  38
  39             pos = 0
  40             lineno = token.lineno
  41
  42             while 1:
  43                 if not paren_stack:
  44                     match = _outside_re.search(token.value, pos)
  45                 else:
  46                     match = _inside_re.search(token.value, pos)
  47                 if match is None:
  48                     break
  49                 new_pos = match.start()
  50                 if new_pos > pos:
  51                     preval = token.value[pos:new_pos]
  52                     yield Token(lineno, 'data', preval)
  53                     lineno += count_newlines(preval)
  54                 gtok = match.group()
  55                 if gtok[0] == '\\':
  56                     yield Token(lineno, 'data', gtok[1:])
  57                 elif not paren_stack:
  58                     yield Token(lineno, 'block_begin', None)
  59                     yield Token(lineno, 'name', 'trans')
  60                     yield Token(lineno, 'block_end', None)
  61                     paren_stack = 1
  62                 else:
  63                     if gtok == '(' or paren_stack > 1:
  64                         yield Token(lineno, 'data', gtok)
  65                     paren_stack += gtok == ')' and -1 or 1
  66                     if not paren_stack:
  67                         yield Token(lineno, 'block_begin', None)
  68                         yield Token(lineno, 'name', 'endtrans')
  69                         yield Token(lineno, 'block_end', None)
  70                 pos = match.end()
  71
  72             if pos < len(token.value):
  73                 yield Token(lineno, 'data', token.value[pos:])
  74
  75         if paren_stack:
  76             raise TemplateSyntaxError('unclosed gettext expression',
  77                                       token.lineno, stream.name,
  78                                       stream.filename)