Merged shane-better-tracebacks-branch. The changes are explained in h…

…ttp://dev.zope.org/Wikis/DevSite/Proposals/BetterTracebacks

ExceptionFormatter.py

@@ -0,0 +1,253 @@
+##############################################################################
+#
+# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
+# All Rights Reserved.
+# 
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+# 
+##############################################################################
+"""An exception formatter that shows traceback supplements and traceback info,
+optionally in HTML.
+
+$Id: ExceptionFormatter.py,v 1.2 2002/04/03 20:43:59 shane Exp $
+"""
+
+import sys
+import cgi
+
+
+DEBUG_EXCEPTION_FORMATTER = 1
+
+
+class TextExceptionFormatter:
+
+    line_sep = '\n'
+    show_revisions = 0
+
+    def __init__(self, limit=None):
+        self.limit = limit
+
+    def escape(self, s):
+        return s
+
+    def getPrefix(self):
+        return 'Traceback (innermost last):'
+
+    def getLimit(self):
+        limit = self.limit
+        if limit is None:
+            limit = getattr(sys, 'tracebacklimit', None)
+        return limit
+
+    def getRevision(self, globals):
+        if not self.show_revisions:
+            return None
+        revision = globals.get('__revision__', None)
+        if revision is None:
+            # Incorrect but commonly used spelling
+            revision = globals.get('__version__', None)
+
+        if revision is not None:
+            try:
+                revision = str(revision).strip()
+            except:
+                revision = '???'
+        return revision
+
+    def formatSupplementLine(self, line):
+        return '   - %s' % line
+
+    def formatObject(self, object):
+        return [self.formatSupplementLine(repr(object))]
+
+    def formatSourceURL(self, url):
+        return [self.formatSupplementLine('URL: %s' % url)]
+
+    def formatSupplement(self, supplement, tb):
+        result = []
+        fmtLine = self.formatSupplementLine
+
+        object = getattr(supplement, 'object', None)
+        if object is not None:
+            result.extend(self.formatObject(object))
+
+        url = getattr(supplement, 'source_url', None)
+        if url is not None:
+            result.extend(self.formatSourceURL(url))
+
+        line = getattr(supplement, 'line', 0)
+        if line == -1:
+            line = tb.tb_lineno
+        col = getattr(supplement, 'column', -1)
+        if line:
+            if col is not None and col >= 0:
+                result.append(fmtLine('Line %s, Column %s' % (
+                    line, col)))
+            else:
+                result.append(fmtLine('Line %s' % line))
+        elif col is not None and col >= 0:
+            result.append(fmtLine('Column %s' % col))
+
+        expr = getattr(supplement, 'expression', None)
+        if expr:
+            result.append(fmtLine('Expression: %s' % expr))
+
+        warnings = getattr(supplement, 'warnings', None)
+        if warnings:
+            for warning in warnings:
+                result.append(fmtLine('Warning: %s' % warning))
+
+        extra = self.formatExtraInfo(supplement)
+        if extra:
+            result.append(extra)
+        return result
+
+    def formatExtraInfo(self, supplement):
+        getInfo = getattr(supplement, 'getInfo', None)
+        if getInfo is not None:
+            extra = getInfo()
+            if extra:
+                return extra
+        return None        
+
+    def formatTracebackInfo(self, tbi):
+        return self.formatSupplementLine('__traceback_info__: %s' % tbi)
+
+    def formatLine(self, tb):
+        f = tb.tb_frame
+        lineno = tb.tb_lineno
+        co = f.f_code
+        filename = co.co_filename
+        name = co.co_name
+        locals = f.f_locals
+        globals = f.f_globals
+        modname = globals.get('__name__', filename)
+
+        s = '  Module %s, line %d' % (modname, lineno)
+
+        revision = self.getRevision(globals)
+        if revision:
+            s = s + ', rev. %s' % revision
+
+        s = s + ', in %s' % name
+
+        result = []
+        result.append(self.escape(s))
+
+        # Output a traceback supplement, if any.
+        if locals.has_key('__traceback_supplement__'):
+            # Use the supplement defined in the function.
+            tbs = locals['__traceback_supplement__']
+        elif globals.has_key('__traceback_supplement__'):
+            # Use the supplement defined in the module.
+            # This is used by Scripts (Python).
+            tbs = globals['__traceback_supplement__']
+        else:
+            tbs = None
+        if tbs is not None:
+            factory = tbs[0]
+            args = tbs[1:]
+            try:
+                supp = factory(*args)
+                result.extend(self.formatSupplement(supp, tb))
+            except:
+                if DEBUG_EXCEPTION_FORMATTER:
+                    import traceback
+                    traceback.print_exc()
+                # else just swallow the exception.
+
+        try:
+            tbi = locals.get('__traceback_info__', None)
+            if tbi is not None:
+                result.append(self.formatTracebackInfo(tbi))
+        except:
+            pass
+
+        return self.line_sep.join(result)
+
+    def formatExceptionOnly(self, etype, value):
+        import traceback
+        return self.line_sep.join(
+            traceback.format_exception_only(etype, value))
+
+    def formatLastLine(self, exc_line):
+        return self.escape(exc_line)
+
+    def formatException(self, etype, value, tb, limit=None):
+        # The next line provides a way to detect recursion.
+        __exception_formatter__ = 1
+        result = [self.getPrefix() + '\n']
+        if limit is None:
+            limit = self.getLimit()
+        n = 0
+        while tb is not None and (limit is None or n < limit):
+            if tb.tb_frame.f_locals.get('__exception_formatter__'):
+                # Stop recursion.
+                result.append('(Recursive formatException() stopped)\n')
+                break
+            line = self.formatLine(tb)
+            result.append(line + '\n')
+            tb = tb.tb_next
+            n = n + 1
+        exc_line = self.formatExceptionOnly(etype, value)
+        result.append(self.formatLastLine(exc_line))
+        return result
+
+
+
+class HTMLExceptionFormatter (TextExceptionFormatter):
+
+    line_sep = '<br />\r\n'
+
+    def escape(self, s):
+        return cgi.escape(s)
+
+    def getPrefix(self):
+        return '<p>Traceback (innermost last):\r\n<ul>'
+
+    def formatSupplementLine(self, line):
+        return '<b>%s</b>' % self.escape(str(line))
+
+    def formatTracebackInfo(self, tbi):
+        s = self.escape(str(tbi))
+        s = s.replace('\n', self.line_sep)
+        return '__traceback_info__: %s' % s
+
+    def formatLine(self, tb):
+        line = TextExceptionFormatter.formatLine(self, tb)
+        return '<li>%s</li>' % line
+
+    def formatLastLine(self, exc_line):
+        return '</ul>%s</p>' % self.escape(exc_line)
+
+    def formatExtraInfo(self, supplement):
+        getInfo = getattr(supplement, 'getInfo', None)
+        if getInfo is not None:
+            extra = getInfo(1)
+            if extra:
+                return extra
+        return None        
+
+
+
+limit = 200
+
+if hasattr(sys, 'tracebacklimit'):
+    limit = min(limit, sys.tracebacklimit)
+
+text_formatter = TextExceptionFormatter(limit)
+html_formatter = HTMLExceptionFormatter(limit)
+
+
+def format_exception(t, v, tb, limit=None, as_html=0):
+    if as_html:
+        fmt = html_formatter
+    else:
+        fmt = text_formatter
+    return fmt.formatException(t, v, tb, limit=limit)
+

ITracebackSupplement.py

@@ -0,0 +1,92 @@
+##############################################################################
+#
+# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
+# All Rights Reserved.
+# 
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+# 
+##############################################################################
+"""ITracebackSupplement interface definition.
+
+$Id: ITracebackSupplement.py,v 1.2 2002/04/03 20:44:00 shane Exp $
+"""
+
+
+from Interface import Interface
+from Interface.Attribute import Attribute
+
+class ITracebackSupplement(Interface):
+    """Provides valuable information to supplement an exception traceback.
+
+    The interface is geared toward providing meaningful feedback when
+    exceptions occur in user code written in mini-languages like
+    Zope page templates and restricted Python scripts.
+    """
+
+    source_url = Attribute(
+        'source_url',
+        """Optional.  Set to URL of the script where the exception occurred.
+
+        Normally this generates a URL in the traceback that the user
+        can visit to manage the object.  Set to None if unknown or
+        not available.
+        """
+        )
+
+    object = Attribute(
+        'object',
+        """Optional.  Set to the script or template where the exception
+        occurred.
+
+        Set to None if unknown or not available.
+        """
+        )
+
+    line = Attribute(
+        'line',
+        """Optional.  Set to the line number (>=1) where the exception
+        occurred.
+
+        Set to 0 or None if the line number is unknown.
+        """
+        )
+
+    column = Attribute(
+        'column',
+        """Optional.  Set to the column offset (>=0) where the exception
+        occurred.
+
+        Set to None if the column number is unknown.
+        """
+        )
+
+    expression = Attribute(
+        'expression',
+        """Optional.  Set to the expression that was being evaluated.
+
+        Set to None if not available or not applicable.
+        """
+        )
+
+    warnings = Attribute(
+        'warnings',
+        """Optional.  Set to a sequence of warning messages.
+
+        Set to None if not available, not applicable, or if the exception
+        itself provides enough information.
+        """
+        )
+
+
+    def getInfo(as_html=0):
+        """Optional.  Returns a string containing any other useful info.
+
+        If as_html is set, the implementation must HTML-quote the result
+        (normally using cgi.escape()).  Returns None to provide no
+        extra info.
+        """

tests/__init__.py

@@ -0,0 +1 @@
+"""Package for zExceptions tests"""