1 files changed, 40 insertions, 0 deletions
diff --git a/mobile/android/gen_from_jinja.py b/mobile/android/gen_from_jinja.py
new file mode 100644
index 0000000000..6c625226ee
--- /dev/null
+++ b/mobile/android/gen_from_jinja.py
@@ -0,0 +1,40 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+
+from jinja2 import Environment, FileSystemLoader, StrictUndefined
+
+
+def main(output_fd, input_filename, *args):
+    # FileSystemLoader requires the path to the directory containing templates,
+    # not the file name of the template itself. We hang onto the leaf name
+    # which will shortly be passed to Environment.get_template.
+    (path, leaf) = os.path.split(input_filename)
+
+    # Jinja's default value for undefined is too permissive and would allow
+    # omissions to slip into the generated output. We set undefined to
+    # StrictUndefined to force Jinja to raise an exception any time a required
+    # value is missing.
+    env = Environment(
+        loader=FileSystemLoader(path, encoding="utf-8"),
+        autoescape=True,
+        undefined=StrictUndefined,
+    )
+    tpl = env.get_template(leaf)
+
+    context = dict()
+
+    # args should all be key=value pairs that will be added to the context.
+    # Note that all values are *strings*, so the Jinja template may need to
+    # convert them to other types during processing.
+    # (As in Python, the empty string is falsy, so simple boolean checks are possible)
+    for arg in args:
+        (k, v) = arg.split("=", 1)
+        context[k] = v
+
+    # Now run the template and send its output directly to output_fd
+    tpl.stream(context).dump(output_fd, encoding="utf-8")