def translate_exception(template, context, exc_type, exc_value, tb):
"""
Translate an exception and return the new traceback.
"""
# depending on the python version we have to skip some frames to
# step to get the frame of the current template. The frames before
# are the toolchain used to render that thing.
for x in xrange(RUNTIME_EXCEPTION_OFFSET):
tb = tb.tb_next
result_tb = prev_tb = None
initial_tb = tb
# translate all the jinja frames in this traceback
while tb is not None:
if tb.tb_frame.f_globals.get('__jinja_template__'):
debug_info = tb.tb_frame.f_globals['debug_info']
# the next thing we do is matching the current error line against the
# debugging table to get the correct source line. If we can't find the
# filename and line number we return the traceback object unaltered.
error_line = tb.tb_lineno
for code_line, tmpl_filename, tmpl_line in reversed(debug_info):
if code_line <= error_line:
source = tb.tb_frame.f_globals['template_source']
tb = fake_template_exception(exc_type, exc_value, tb,
tmpl_filename, tmpl_line,
source, context, prev_tb)[-1]
break
if result_tb is None:
result_tb = tb
prev_tb = tb
tb = tb.tb_next
# under some conditions we cannot translate any frame. in that
# situation just return the original traceback.
return (exc_type, exc_value, result_tb or intial_tb)
def wrapped(env, context, seq):
try:
return iter(reversed(seq)).next()
except StopIteration:
return env.undefined_singleton
def wrapped(env, context, seq):
try:
return iter(reversed(seq)).next()
except StopIteration:
return env.undefined_singleton