--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/views/dotgraphview.py	Tue Aug 10 16:10:28 2010 +0200
@@ -0,0 +1,80 @@
+# copyright 2003-2010 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of CubicWeb.
+#
+# CubicWeb is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
+"""some basic stuff to build dot generated graph images"""
+
+__docformat__ = "restructuredtext en"
+_ = unicode
+
+import tempfile
+import os
+
+from logilab.mtconverter import xml_escape
+from logilab.common.graph import GraphGenerator, DotBackend
+
+from cubicweb.view import EntityView
+from cubicweb.utils import make_uid
+
+class DotGraphView(EntityView):
+    __abstract__ = True
+
+    def cell_call(self, row, col):
+        entity = self.cw_rset.get_entity(row, col)
+        visitor = self.build_visitor(entity)
+        prophdlr = self.build_dotpropshandler()
+        graphname = 'dotgraph%s' % str(entity.eid)
+        generator = GraphGenerator(DotBackend(graphname, None,
+                                              ratio='compress', size='30,10'))
+        # map file
+        pmap, mapfile = tempfile.mkstemp(".map", graphname)
+        os.close(pmap)
+        # image file
+        fd, tmpfile = tempfile.mkstemp('.png')
+        os.close(fd)
+        generator.generate(visitor, prophdlr, tmpfile, mapfile)
+        filekeyid = make_uid()
+        self._cw.session.data[filekeyid] = tmpfile
+        self.w(u'<img src="%s" alt="%s" usemap="#%s" />' % (
+            xml_escape(entity.absolute_url(vid='tmppng', tmpfile=filekeyid)),
+            xml_escape(self._cw._('Data connection graph for %s') % entity.name),
+            graphname))
+        stream = open(mapfile, 'r').read()
+        stream = stream.decode(self._cw.encoding)
+        self.w(stream)
+        os.unlink(mapfile)
+
+    def build_visitor(self, entity):
+        raise NotImplementedError
+
+    def build_dotpropshandler(self):
+        return DotGraphPropsHandler(self._cw)
+
+
+class DotPropsHandler(object):
+    def __init__(self, req):
+        self._ = req._
+
+    def node_properties(self, entity):
+        """return default DOT drawing options for a state or transition"""
+        return {'label': entity.printable_value('name'),
+                'href': entity.absolute_url(),
+                'fontname': 'Courier', 'fontsize': 10, 'shape':'box',
+                 }
+
+    def edge_properties(self, transition, fromstate, tostate):
+        return {'label': '', 'dir': 'forward',
+                'color': 'black', 'style': 'filled'}