Improvements in XmlMarshaller: any Python variable may be the root of a structure to marshall.

shared/xml_parser.py

@@ -17,7 +17,7 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,USA.
 
 # ------------------------------------------------------------------------------
-import xml.sax, difflib
+import xml.sax, difflib, types
 from xml.sax.handler import ContentHandler, ErrorHandler
 from xml.sax.xmlreader import InputSource
 from appy.shared import UnicodeBuffer
@@ -401,6 +401,15 @@ class XmlMarshaller:
             self.dumpString(res, value)
         elif isinstance(value, bool):
             res.write(self.trueFalse[value])
+        elif self.isAnObject(value):
+            if hasattr(value, 'absolute_url'):
+                res.write(value.absolute_url())
+            else:
+                res.write(value)
+            # We could dump the entire object content, too. Maybe we could add a
+            # parameter to the marshaller to know how to marshall objects
+            # (produce an ID, an URL, include the entire tag but we need to take
+            # care of circular references,...)
         else:
             res.write(value)
 
@@ -434,21 +443,38 @@ class XmlMarshaller:
         self.dumpValue(res, fieldValue, fieldType)
         res.write('</'); res.write(fieldName); res.write('>')
 
+    def isAnObject(self, instance):
+        '''Returns True if p_instance is a class instance, False if it is a
+           basic type, or tuple, sequence, etc.'''
+        iType = type(instance)
+        if iType == types.InstanceType:
+            return True
+        elif iType.__name__ == 'ImplicitAcquirerWrapper':
+            # This is the case with Archetype instances
+            return True
+        return False
+
     def marshall(self, instance, objectType='popo'):
         '''Returns in a UnicodeBuffer the XML version of p_instance. If
            p_instance corresponds to a Plain Old Python Object, specify 'popo'
            for p_objectType. If p_instance corresponds to an Archetypes object
            (Zope/Plone), specify 'archetype' for p_objectType. if p_instance is
-           a Appy object, specify "appy" as p_objectType.'''
+           a Appy object, specify "appy" as p_objectType. If p_instance is not
+           an instance at all, but another Python data structure or basic type,
+           p_objectType is ignored.'''
+        # Call the XmlMarshaller constructor if it hasn't been called yet.
         if not hasattr(self, 'cdata'):
-            # The constructor has not been called. Do it now.
             XmlMarshaller.__init__(self)
+        # Create the buffer where the XML result will be dumped.
         res = UnicodeBuffer()
-        # Dump the XML prologue and root element
+        # Dump the XML prologue
+        res.write(self.xmlPrologue)
+        if self.isAnObject(instance):
+            # Determine object ID
             if objectType in ('archetype', 'appy'):
                 objectId = instance.UID() # ID in DB
-        else: objectId = str(id(instance)) # ID in RAM
+            else:
-        res.write(self.xmlPrologue)
+                objectId = str(id(instance)) # ID in RAM
             res.write('<'); res.write(self.rootElementName)
             res.write(' type="object" id="');res.write(objectId);res.write('">')
             # Dump the object ID and the value of the fields that must be dumped
@@ -460,8 +486,8 @@ class XmlMarshaller:
                     elif self.fieldsToMarshall == 'all':
                         mustDump = True
                     else:
-                    if (type(self.fieldsToMarshall) in self.sequenceTypes) and \
+                        if (type(self.fieldsToMarshall) in self.sequenceTypes) \
-                       (fieldName in self.fieldsToMarshall):
+                           and (fieldName in self.fieldsToMarshall):
                             mustDump = True
                     if mustDump:
                         self.dumpField(res, fieldName, fieldValue)
@@ -478,8 +504,8 @@ class XmlMarshaller:
                     elif self.fieldsToMarshall == 'all_with_metadata':
                         mustDump = True
                     else:
-                    if (type(self.fieldsToMarshall) in self.sequenceTypes) and \
+                        if (type(self.fieldsToMarshall) in self.sequenceTypes) \
-                       (field.getName() in self.fieldsToMarshall):
+                           and (field.getName() in self.fieldsToMarshall):
                             mustDump = True
                     if mustDump:
                         fieldType = 'basic'
@@ -497,12 +523,15 @@ class XmlMarshaller:
                         history = instance.workflow_history[wfInfo[0].id]
                         for event in history:
                             res.write('<event type="object">')
-                        for k, v in event.iteritems(): self.dumpField(res, k, v)
+                            for k, v in event.iteritems():
+                                self.dumpField(res, k, v)
                             res.write('</event>')
                     res.write('</history>')
             self.marshallSpecificElements(instance, res)
-        # Return the result
             res.write('</'); res.write(self.rootElementName); res.write('>')
+        else:
+            self.dumpField(res, self.rootElementName, instance)
+        # Return the result
         res = res.getValue()
         if not self.dumpUnicode:
             res = res.encode('utf-8')