Added FilterMessages transform (removes system messages below the verbosity threshold)

git-svn-id: http://svn.code.sf.net/p/docutils/code/trunk@1811 929543f6-e4f2-0310-98a6-ba3bd3dd1d04

4 files changed, 33 insertions, 2 deletions

diff --git a/docutils/HISTORY.txt b/docutils/HISTORY.txt
index bf35db11d..7fd37c1bc 100644
--- a/docutils/HISTORY.txt
+++ b/docutils/HISTORY.txt
@@ -186,6 +186,11 @@ Changes Since 0.3
 * docutils/parsers/rst/languages/ru.py: Added to project; Russian
   mappings by Roman Suzi.
 
+* docutils/transforms/universal.py:
+
+  - Added FilterMessages transform (removes system messages below the
+    verbosity threshold).
+
 * docutils/writers/html4css1.py:
 
   - Fixed unicode handling of attribute values (bug 760673).
diff --git a/docutils/docs/ref/transforms.txt b/docutils/docs/ref/transforms.txt
index 4c5fe135a..fa866487c 100644
--- a/docutils/docs/ref/transforms.txt
+++ b/docutils/docs/ref/transforms.txt
@@ -71,7 +71,9 @@ universal.FinalChecks           Transformer                   840
 
 universal.Messages              Transformer                   860
 
-universal.TestMessages          DocutilsTestSupport           890
+universal.FilterMessages        Transformer                   870
+
+universal.TestMessages          DocutilsTestSupport           880
 
 misc.CallBack                   n/a                           990
 ==============================  ============================  ========
diff --git a/docutils/docutils/transforms/__init__.py b/docutils/docutils/transforms/__init__.py
index 24cc4771f..aa3e1b525 100644
--- a/docutils/docutils/transforms/__init__.py
+++ b/docutils/docutils/transforms/__init__.py
@@ -76,7 +76,8 @@ class Transformer(TransformSpec):
 
     default_transforms = (universal.Decorations,
                           universal.FinalChecks,
-                          universal.Messages)
+                          universal.Messages,
+                          universal.FilterMessages)
     """These transforms are applied to all document trees."""
 
     def __init__(self, document):
diff --git a/docutils/docutils/transforms/universal.py b/docutils/docutils/transforms/universal.py
index 4523304f2..e7d1f150c 100644
--- a/docutils/docutils/transforms/universal.py
+++ b/docutils/docutils/transforms/universal.py
@@ -111,6 +111,29 @@ class Messages(Transform):
             self.document += section
 
 
+class FilterMessages(Transform):
+
+    """
+    Remove system messages below verbosity threshold.
+    """
+
+    default_priority = 870
+
+    def apply(self):
+        visitor = SystemMessageFilterVisitor(self.document)
+        self.document.walk(visitor)
+
+
+class SystemMessageFilterVisitor(nodes.SparseNodeVisitor):
+
+    def unknown_visit(self, node):
+        pass
+
+    def visit_system_message(self, node):
+        if node['level'] < self.document.reporter['writer'].report_level:
+            node.parent.remove(node)
+
+
 class TestMessages(Transform):
 
     """