# exceptions.py
# Copyright (C) 2006, 2007, 2008, 2009, 2010 Michael Bayer mike_mp@zzzcomputing.com
#
# This module is part of Mako and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""exception classes"""
import traceback, sys, re
from mako import util
class MakoException(Exception):
pass
class RuntimeException(MakoException):
pass
def _format_filepos(lineno, pos, filename):
if filename is None:
return " at line: %d char: %d" % (lineno, pos)
else:
return " in file '%s' at line: %d char: %d" % (filename, lineno, pos)
class CompileException(MakoException):
def __init__(self, message, source, lineno, pos, filename):
MakoException.__init__(self, message + _format_filepos(lineno, pos, filename))
self.lineno =lineno
self.pos = pos
self.filename = filename
self.source = source
class SyntaxException(MakoException):
def __init__(self, message, source, lineno, pos, filename):
MakoException.__init__(self, message + _format_filepos(lineno, pos, filename))
self.lineno =lineno
self.pos = pos
self.filename = filename
self.source = source
class UnsupportedError(MakoException):
"""raised when a retired feature is used."""
class TemplateLookupException(MakoException):
pass
class TopLevelLookupException(TemplateLookupException):
pass
class RichTraceback(object):
"""pulls the current exception from the sys traceback and extracts Mako-specific
template information.
Usage:
RichTraceback()
Properties:
error - the exception instance.
message - the exception error message as unicode
source - source code of the file where the error occured. if the error occured within a compiled template,
this is the template source.
lineno - line number where the error occured. if the error occured within a compiled template, the line number
is adjusted to that of the template source
records - a list of 8-tuples containing the original python traceback elements, plus the
filename, line number, source line, and full template source for the traceline mapped back to its originating source
template, if any for that traceline (else the fields are None).
reverse_records - the list of records in reverse
traceback - a list of 4-tuples, in the same format as a regular python traceback, with template-corresponding
traceback records replacing the originals
reverse_traceback - the traceback list in reverse
"""
def __init__(self, error=None, traceback=None):
self.source, self.lineno = "", 0
if error is None or traceback is None:
t, value, tback = sys.exc_info()
if error is None:
error = value or t
if traceback is None:
traceback = tback
self.error = error
self.records = self._init(traceback)
if isinstance(self.error, (CompileException, SyntaxException)):
import mako.template
self.source = self.error.source
self.lineno = self.error.lineno
self._has_source = True
self._init_message()
def _init_message(self):
"""Find a unicode representation of self.error"""
try:
self.message = unicode(self.error)
except UnicodeError:
try:
self.message = str(self.error)
except UnicodeEncodeError:
# Fallback to args as neither unicode nor
# str(Exception(u'\xe6')) work in Python < 2.6
self.message = self.error.args[0]
if not isinstance(self.message, unicode):
self.message = unicode(self.message, 'ascii', 'replace')
def _get_reformatted_records(self, records):
for rec in records:
if rec[6] is not None:
yield (rec[4], rec[5], rec[2], rec[6])
else:
yield tuple(rec[0:4])
@property
def traceback(self):
"""return a list of 4-tuple traceback records (i.e. normal python format)
with template-corresponding lines remapped to the originating template
"""
return list(self._get_reformatted_records(self.records))
@property
def reverse_records(self):
return reversed(self.records)
@property
def reverse_traceback(self):
"""return the same data as traceback, except in reverse order
"""
return list(self._get_reformatted_records(self.reverse_records))
def _init(self, trcback):
"""format a traceback from sys.exc_info() into 7-item tuples, containing
the regular four traceback tuple items, plus the original template
filename, the line number adjusted relative to the template source, and
code line from that line number of the template."""
import mako.template
mods = {}
rawrecords = traceback.extract_tb(trcback)
new_trcback = []
for filename, lineno, function, line in rawrecords:
try:
(line_map, template_lines) = mods[filename]
except KeyError:
try:
info = mako.template._get_module_info(filename)
module_source = info.code
template_source = info.source
template_filename = info.template_filename or filename
except KeyError:
# A normal .py file (not a Template)
if not util.py3k:
try:
fp = open(filename, 'rb')
encoding = util.parse_encoding(fp)
fp.close()
except IOError:
encoding = None
if encoding:
line = line.decode(encoding)
else:
line = line.decode('ascii', 'replace')
new_trcback.append((filename, lineno, function, line,
None, None, None, None))
continue
template_ln = module_ln = 1
line_map = {}
for line in module_source.split("\n"):
match = re.match(r'\s*# SOURCE LINE (\d+)', line)
if match:
template_ln = int(match.group(1))
else:
template_ln += 1
module_ln += 1
line_map[module_ln] = template_ln
template_lines = [line for line in template_source.split("\n")]
mods[filename] = (line_map, template_lines)
template_ln = line_map[lineno]
if template_ln <= len(template_lines):
template_line = template_lines[template_ln - 1]
else:
template_line = None
new_trcback.append((filename, lineno, function,
line, template_filename, template_ln,
template_line, template_source))
if not self.source:
for l in range(len(new_trcback)-1, 0, -1):
if new_trcback[l][5]:
self.source = new_trcback[l][7]
self.lineno = new_trcback[l][5]
break
else:
try:
# A normal .py file (not a Template)
fp = open(new_trcback[-1][0], 'rb')
encoding = util.parse_encoding(fp)
fp.seek(0)
self.source = fp.read()
fp.close()
if encoding:
self.source = self.source.decode(encoding)
except IOError:
self.source = ''
self.lineno = new_trcback[-1][1]
return new_trcback
def text_error_template(lookup=None):
"""provides a template that renders a stack trace in a similar format to the Python interpreter,
substituting source template filenames, line numbers and code for that of the originating
source template, as applicable."""
import mako.template
return mako.template.Template(r"""
<%page args="error=None, traceback=None"/>
<%!
from mako.exceptions import RichTraceback
%>\
<%
tback = RichTraceback(error=error, traceback=traceback)
%>\
Traceback (most recent call last):
% for (filename, lineno, function, line) in tback.traceback:
File "${filename}", line ${lineno}, in ${function or '?'}
${line | unicode.strip}
% endfor
${str(tback.error.__class__.__name__)}: ${tback.message}
""")
def html_error_template():
"""provides a template that renders a stack trace in an HTML format, providing an excerpt of
code as well as substituting source template filenames, line numbers and code
for that of the originating source template, as applicable.
the template's default encoding_errors value is 'htmlentityreplace'. the template has
two options:
with the full option disabled, only a section of an HTML document is returned.
with the css option disabled, the default stylesheet won't be included."""
import mako.template
return mako.template.Template(r"""
<%!
from mako.exceptions import RichTraceback
%>
<%page args="full=True, css=True, error=None, traceback=None"/>
% if full:
<html>
<head>
<title>Mako Runtime Error</title>
% endif
% if css:
<style>
body { font-family:verdana; margin:10px 30px 10px 30px;}
.stacktrace { margin:5px 5px 5px 5px; }
.highlight { padding:0px 10px 0px 10px; background-color:#9F9FDF; }
.nonhighlight { padding:0px; background-color:#DFDFDF; }
.sample { padding:10px; margin:10px 10px 10px 10px; font-family:monospace; }
.sampleline { padding:0px 10px 0px 10px; }
.sourceline { margin:5px 5px 10px 5px; font-family:monospace;}
.location { font-size:80%; }
</style>
% endif
% if full:
</head>
<body>
% endif
<h2>Error !</h2>
<%
tback = RichTraceback(error=error, traceback=traceback)
src = tback.source
line = tback.lineno
if src:
lines = src.split('\n')
else:
lines = None
%>
<h3>${str(tback.error.__class__.__name__)}: ${tback.message}</h3>
% if lines:
<div class="sample">
<div class="nonhighlight">
% for index in range(max(0, line-4),min(len(lines), line+5)):
% if index + 1 == line:
<div class="highlight">${index + 1} ${lines[index] | h}</div>
% else:
<div class="sampleline">${index + 1} ${lines[index] | h}</div>
% endif
% endfor
</div>
</div>
% endif
<div class="stacktrace">
% for (filename, lineno, function, line) in tback.reverse_traceback:
<div class="location">${filename}, line ${lineno}:</div>
<div class="sourceline">${line | h}</div>
% endfor
</div>
% if full:
</body>
</html>
% endif
""", output_encoding=sys.getdefaultencoding(), encoding_errors='htmlentityreplace')
|