mobile/android/gen_from_jinja.py

   1 # -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
   2 # vim: set filetype=python:
   3 # This Source Code Form is subject to the terms of the Mozilla Public
   4 # License, v. 2.0. If a copy of the MPL was not distributed with this
   5 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   6
   7 import os
   8
   9 from jinja2 import Environment, FileSystemLoader, StrictUndefined
  10
  11
  12 def main(output_fd, input_filename, *args):
  13     # FileSystemLoader requires the path to the directory containing templates,
  14     # not the file name of the template itself. We hang onto the leaf name
  15     # which will shortly be passed to Environment.get_template.
  16     (path, leaf) = os.path.split(input_filename)
  17
  18     # Jinja's default value for undefined is too permissive and would allow
  19     # omissions to slip into the generated output. We set undefined to
  20     # StrictUndefined to force Jinja to raise an exception any time a required
  21     # value is missing.
  22     env = Environment(
  23         loader=FileSystemLoader(path, encoding="utf-8"),
  24         autoescape=True,
  25         undefined=StrictUndefined,
  26     )
  27     tpl = env.get_template(leaf)
  28
  29     context = dict()
  30
  31     # args should all be key=value pairs that will be added to the context.
  32     # Note that all values are *strings*, so the Jinja template may need to
  33     # convert them to other types during processing.
  34     # (As in Python, the empty string is falsy, so simple boolean checks are possible)
  35     for arg in args:
  36         (k, v) = arg.split("=", 1)
  37         context[k] = v
  38
  39     # Now run the template and send its output directly to output_fd
  40     tpl.stream(context).dump(output_fd, encoding="utf-8")