rewrite xml_to_text transform using lxml, so as to support other encoding than utf-8.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@39077 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/PortalTransforms/transforms/xml_to_text.py

-from Products.PortalTransforms.libtransforms.retransform import retransform
+from Products.PortalTransforms.interfaces import itransform
+from zope.interface import implements
+from lxml import etree
 
-class xml_to_text(retransform):
+class xml_to_text:
+    implements(itransform)
+
+    __name__ = 'xml_to_text'
     inputs  = ('text/xml', 'application/xml')
     output = 'text/plain'
 
+    def name(self):
+        return self.__name__
+
+    def convert(self, data, cache, **kw):
+        out = ''.join(etree.fromstring(data).itertext()).encode('utf-8')
+        cache.setData(out)
+        return cache
+
 def register():
-    return xml_to_text("xml_to_text",
-                       ('<[^>]*>', ' '),
-                       )
+    return xml_to_text()