# mako/exceptions.py
# Copyright 2006-2025 the Mako authors and contributors <see AUTHORS file>
#
# This module is part of Mako and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""exception classes"""
import sys
import traceback
from mako import compat
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 NameConflictError(MakoException):
"""raised when a reserved word is used inappropriately"""
class TemplateLookupException(MakoException):
pass
class TopLevelLookupException(TemplateLookupException):
pass
class RichTraceback:
"""Pull the current exception from the ``sys`` traceback and extracts
Mako-specific template information.
See the usage examples in :ref:`handling_exceptions`.
"""
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)):
self.source = self.error.source
self.lineno = self.error.lineno
self._has_source = True
self._init_message()
@property
def errorname(self):
return compat.exception_name(self.error)
def _init_message(self):
"""Find a unicode representation of self.error"""
try:
self.message = str(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, str):
self.message = str(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:
if not line:
line = ""
try:
(line_map, template_lines, template_filename) = 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 info.template_uri or filename
)
except KeyError:
# A normal .py file (not a Template)
new_trcback.append(
(
filename,
lineno,
function,
line,
None,
None,
None,
None,
)
)
continue
template_ln = 1
mtm = mako.template.ModuleInfo
source_map = mtm.get_module_source_metadata(
module_source, full_line_map=True
)
line_map = source_map["full_line_map"]
template_lines = [
line_ for line_ in template_source.split("\n")
]
mods[filename] = (line_map, template_lines, template_filename)
template_ln = line_map[lineno - 1]
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:
if new_trcback:
try:
# A normal .py file (not a Template)
with open(new_trcback[-1][0], "rb") as fp:
encoding = util.parse_encoding(fp)
if not encoding:
encoding = "utf-8"
fp.seek(0)
self.source = fp.read()
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 | trim}
% endfor
${tback.errorname}: ${tback.message}
"""
)
def _install_pygments():
global syntax_highlight, pygments_html_formatter
from mako.ext.pygmentplugin import syntax_highlight # noqa
from mako.ext.pygmentplugin import pygments_html_formatter # noqa
def _install_fallback():
global syntax_highlight, pygments_html_formatter
from mako.filters import html_escape
pygments_html_formatter = None
def syntax_highlight(filename="", language=None):
return html_escape
def _install_highlighting():
try:
_install_pygments()
except ImportError:
_install_fallback()
_install_highlighting()
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, syntax_highlight,\
pygments_html_formatter
%>
<%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%; }
.highlight { white-space:pre; }
.sampleline { white-space:pre; }
% if pygments_html_formatter:
${pygments_html_formatter.get_style_defs()}
.linenos { min-width: 2.5em; text-align: right; }
pre { margin: 0; }
.syntax-highlighted { padding: 0 10px; }
.syntax-highlightedtable { border-spacing: 1px; }
.nonhighlight { border-top: 1px solid #DFDFDF;
border-bottom: 1px solid #DFDFDF; }
.stacktrace .nonhighlight { margin: 5px 15px 10px; }
.sourceline { margin: 0 0; font-family:monospace; }
.code { background-color: #F8F8F8; width: 100%; }
.error .code { background-color: #FFBDBD; }
.error .syntax-highlighted { background-color: #FFBDBD; }
% endif
</style>
% endif
% if full:
</head>
<body>
% endif
<h2>Error !</h2>
<%
tback = RichTraceback(error=error, traceback=traceback)
src = tback.source
line = tback.lineno
if src:
lines = src.split('\n')
else:
lines = None
%>
<h3>${tback.errorname}: ${tback.message|h}</h3>
% if lines:
<div class="sample">
<div class="nonhighlight">
% for index in range(max(0, line-4),min(len(lines), line+5)):
<%
if pygments_html_formatter:
pygments_html_formatter.linenostart = index + 1
%>
% if index + 1 == line:
<%
if pygments_html_formatter:
old_cssclass = pygments_html_formatter.cssclass
pygments_html_formatter.cssclass = 'error ' + old_cssclass
%>
${lines[index] | syntax_highlight(language='mako')}
<%
if pygments_html_formatter:
pygments_html_formatter.cssclass = old_cssclass
%>
% else:
${lines[index] | syntax_highlight(language='mako')}
% endif
% endfor
</div>
</div>
% endif
<div class="stacktrace">
% for (filename, lineno, function, line) in tback.reverse_traceback:
<div class="location">${filename}, line ${lineno}:</div>
<div class="nonhighlight">
<%
if pygments_html_formatter:
pygments_html_formatter.linenostart = lineno
%>
<div class="sourceline">${line | syntax_highlight(filename)}</div>
</div>
% endfor
</div>
% if full:
</body>
</html>
% endif
""",
output_encoding=sys.getdefaultencoding(),
encoding_errors="htmlentityreplace",
)
