Add <warnfilter> section, which allows you to configure Python warning filters...

Add <warnfilter> section, which allows you to configure Python warning filters in zope.conf.  Useful for suppressing the USELESS DeprecationWarnings that emanate from TALGenerator wrt i18n.

lib/python/Zope/Startup/zopeschema.xml

@@ -198,6 +198,42 @@
 
   <!-- schema begins  -->
 
+  <multisection type="warnfilter" attribute="warnfilters" name="*"
+                dataype="zLOG.warn_filter_handler">
+    <!-- from zLOG -->
+    <description>
+    A multisection which allows a user to set up a Python "warning" filter.
+    The following keys are valid within a warnfilter section:
+
+      action:  one of the following strings:
+
+           "error"   turn matching warnings into exceptions
+           "ignore"  never print matching warnings
+           "always"  always print matching warnings
+           "default" print the first occurrence of matching warnings
+                     for each location where the warning is issued
+           "module"  print the first occurrence of matching warnings
+                     for each module where the warning is issued
+           "once"    print only the first occurrence of matching
+                     warnings, regardless of location
+
+      message:  a string containing a regular expression that the
+                warning message must match (the match is compiled to
+                always be case-insensitive)
+
+      category: a Python dotted-path classname (must be a subclass of
+                Warning) of which the warning category must be a subclass in
+                order to match
+
+      module:   a string containing a regular expression that the
+                module name must match (the match is compiled to be
+                case-sensitive)
+
+      lineno:   an integer that the line number where the warning
+                occurred must match, or 0 to match all line numbers
+    </description>
+  </multisection>
+
   <section type="environment" attribute="environment" name="*">
     <description>
      A section which allows a user to define arbitrary key-value pairs for

lib/python/zLOG/component.xml

@@ -58,4 +58,12 @@
      <multisection type="zLOG.loghandler" attribute="handlers" name="*"/>
   </sectiontype>
 
+  <sectiontype name="warnfilter" datatype=".warning_filter_handler">
+      <key name="action" datatype=".warn_action" default="default"/>
+      <key name="message" default=""/>
+      <key name="category" datatype=".warning_subclass" default="Warning"/>
+      <key name="module" default=""/>
+      <key name="lineno" datatype="integer" default="0"/>
+  </sectiontype>
+
 </component>

lib/python/zLOG/datatypes.py

@@ -238,3 +238,50 @@ class EventLogFactory(Factory):
             if handler_level < lowest:
                 lowest = factory.getLevel()
         return lowest
+
+def importable_name(name):
+    try:
+        components = name.split('.')
+        start = components[0]
+        g = globals()
+        package = __import__(start, g, g)
+        modulenames = [start]
+        for component in components[1:]:
+            modulenames.append(component)
+            try:
+                package = getattr(package, component)
+            except AttributeError:
+                n = '.'.join(modulenames)
+                package = __import__(n, g, g, component)
+        return package
+    except ImportError:
+        raise ValueError, (
+            'The object named by "%s" could not be imported' %  name )
+
+def warning_subclass(val):
+    ob = importable_name(val) # will fail in course
+    try:
+        if not issubclass(ob, Warning):
+            raise ValueError, (
+                'warning category "%s" must be a Warning subclass' % val)
+    except TypeError:
+            raise ValueError, (
+                'warning category "%s" must be a Warning subclass' % val)
+        
+    return ob
+
+def warn_action(val):
+    OK = ("error", "ignore", "always", "default", "module", "once")
+    if val not in OK:
+        raise ValueError, "warning action %s not one of %s" % (val, OK)
+    return val
+
+def warning_filter_handler(section):
+    import warnings
+    # add the warning filter
+    warnings.filterwarnings(section.action, section.message, section.category,
+                            section.module, section.lineno, 1)
+    return section
+
+
+

skel/etc/zope.conf.in

@@ -680,6 +680,51 @@ instancehome $INSTANCE
 #   </nteventlog-handler>
 # </logger>
 
+# Directive: warnfilter
+#
+# Description:
+#     A section that allows you to define a warning filter.
+#     The following keys are valid within a warnfilter section:
+#
+#      action:  one of the following strings:
+#
+#           "error"   turn matching warnings into exceptions
+#           "ignore"  never print matching warnings
+#           "always"  always print matching warnings
+#           "default" print the first occurrence of matching warnings
+#                     for each location where the warning is issued
+#           "module"  print the first occurrence of matching warnings
+#                     for each module where the warning is issued
+#           "once"    print only the first occurrence of matching
+#                     warnings, regardless of location
+#
+#      message:  a string containing a regular expression that the
+#                warning message must match (the match is compiled to
+#                always be case-insensitive)
+#
+#      category: a Python dotted-path classname (must be a subclass of
+#                Warning) of which the warning category must be a subclass in
+#                order to match
+#
+#      module:   a string containing a regular expression that the
+#                module name must match (the match is compiled to be
+#                case-sensitive)
+#
+#      lineno:   an integer that the line number where the warning
+#                occurred must match, or 0 to match all line numbers
+#
+#     All keys within a warnfilter section are optional.  More than
+#     one warnfilter section may be specified.
+#
+# Default: unset
+#
+# Example:
+#
+#    <warnfilter>
+#       action ignore
+#       category exceptions.DeprecationWarning
+#    </warnfilter>
+
 
 # Directive: max-listen-sockets
 #