From 21f839c7292f7f6f24c03dadc9c1a1b0c282aafe Mon Sep 17 00:00:00 2001
From: Narayan Desai <desai@mcs.anl.gov>
Date: Fri, 9 Nov 2007 02:16:44 +0000
Subject: SGenshi improvements from Sebastien Barthelemy (sorry, bad locale)
 and improved error handling

git-svn-id: https://svn.mcs.anl.gov/repos/bcfg/trunk/bcfg2@3944 ce84e21b-d406-0410-9b95-82705330c041
---
 src/lib/Server/Plugins/SGenshi.py | 50 ++++++++++++++++++++++++++++++++-------
 1 file changed, 41 insertions(+), 9 deletions(-)

(limited to 'src/lib/Server/Plugins/SGenshi.py')

diff --git a/src/lib/Server/Plugins/SGenshi.py b/src/lib/Server/Plugins/SGenshi.py
index 11731ef78..76d1dd6bf 100644
--- a/src/lib/Server/Plugins/SGenshi.py
+++ b/src/lib/Server/Plugins/SGenshi.py
@@ -1,37 +1,69 @@
 '''This module implements a templating generator based on Genshi'''
 __revision__ = '$Revision$'
 
-import genshi.template
 import Bcfg2.Server.Plugin
 import lxml.etree, logging
 
 logger = logging.getLogger('Bcfg2.Plugins.SGenshi')
 
+try:
+    import genshi.template, genshi.core, genshi.template.base
+except:
+    logger.error("Failed to load Genshi; disabling SGenshi")
+    raise 
+
+def removecomment(stream):
+    """A genshi filter that removes comments from the stream."""
+    for kind, data, pos in stream:
+        if kind is genshi.core.COMMENT:
+            continue
+        yield kind, data, pos
+
 class TemplateFile(Bcfg2.Server.Plugin.FileBacked):
+    '''Genshi template file object'''
     loader = genshi.template.TemplateLoader(auto_reload=True,
                                             max_cache_size=64)
     def HandleEvent(self, _=None):
-        self.template = self.loader.load(self.name,
-                                         cls=genshi.template.MarkupTemplate)
+        '''Process FAM/GAMIN event'''
+        try:
+            self.template = self.loader.load(self.name,
+                                             cls=genshi.template.MarkupTemplate)
+        except genshi.template.base.TemplateSyntaxError, e:
+            logger.error("SGenshi: Parse failure due to %s" % (e))
         
     def GetValue(self, metadata):
-        stream = self.template.generate(metadata=metadata)
+        '''Build actual structure contents'''
+        if not hasattr(self, 'template'):
+            logger.error("Template data for %s could not be loaded" % self.name)
+            raise Bcfg2.Server.Plugin.PluginExecutionError
+        stream = self.template.generate(metadata=metadata).filter(removecomment)
         data = stream.render('xml')
         return lxml.etree.XML(data)
 
 class SGenshi(Bcfg2.Server.Plugin.Plugin,
               Bcfg2.Server.Plugin.XMLDirectoryBacked):
+    '''SGenshi is a structure plugin that provides direct plugin access to templated structures'''
     __child__ = TemplateFile
     __name__ = 'SGenshi'
     __version__ = '$Id$'
 
     def __init__(self, core, datastore):
         Bcfg2.Server.Plugin.Plugin.__init__(self, core, datastore)
-        Bcfg2.Server.Plugin.XMLDirectoryBacked.__init__(self,
-                                                        self.data,
-                                                        self.core.fam)
+        try:
+            Bcfg2.Server.Plugin.XMLDirectoryBacked.__init__(self,
+                                                            self.data,
+                                                            self.core.fam)
+        except:
+            logger.error("Failed to load SGenshi repository; disabling SGenshi")
+            raise Bcfg2.Server.Plugin.PluginInitError
         
     def BuildStructures(self, metadata):
-        return [entry.GetValue(metadata) \
-                for entry in self.entries.values()]
+        '''Build SGenshi structures'''
+        ret = []
+        for entry in self.entries.values():
+            try:
+                ret.append(entry.GetValue(metadata))
+            except Bcfg2.Server.Plugin.PluginExecutionError:
+                logger.error("SGenshi: Failed to template file %s" % entry.name)
+        return ret
             
-- 
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