custom_retrieve_field_properties, thanks Guyris, issue 710

VERSION

@@ -1 +1 @@
-Version 1.99.7 (2012-03-28 21:01:13) dev
+Version 1.99.7 (2012-03-28 21:37:42) dev

gluon/dal.py

@@ -7517,6 +7517,7 @@ class Field(Expression):
         compute=None,
         custom_store=None,
         custom_retrieve=None,
+        custom_retrieve_fileproperties=None,
         custom_delete=None,
         ):
         self.db = None
@@ -7562,6 +7563,7 @@ class Field(Expression):
         self.isattachment = True
         self.custom_store = custom_store
         self.custom_retrieve = custom_retrieve
+        self.custom_retrieve_fileproperties = custom_retrieve_fileproperties
         self.custom_delete = custom_delete
         if self.label is None:
             self.label = fieldname.replace('_',' ').title()
@@ -7624,14 +7626,11 @@ class Field(Expression):
                 raise http.HTTP(404)
         if self.authorize and not self.authorize(row):
             raise http.HTTP(403)
-        try:
-            m = regex_content.match(name)
-            if not m or not self.isattachment:
-                raise TypeError, 'Can\'t retrieve %s' % name
-            filename = base64.b16decode(m.group('name'), True)
-            filename = regex_cleanup_fn.sub('_', filename)
-        except (TypeError, AttributeError):
-            filename = name
+        m = regex_content.match(name)
+        if not m or not self.isattachment:
+            raise TypeError, 'Can\'t retrieve %s' % name
+        fileproperties = self.retrieve_fileproperties(name,path)
+        filename = fileproperties['filename']
         if isinstance(self.uploadfield, str):  # ## if file is in DB
             return (filename, cStringIO.StringIO(row[self.uploadfield] or ''))
         elif isinstance(self.uploadfield,Field):
@@ -7639,6 +7638,25 @@ class Field(Expression):
             query = self.uploadfield == name
             data = self.uploadfield.table(query)[blob_uploadfield_name]
             return (filename, cStringIO.StringIO(data))
+        else:
+            # ## if file is on filesystem
+            return (filename, open(os.path.join(fileproperties['path'], name), 'rb'))
+
+    def retrieve_fileproperties(self, name, path=None):
+        if self.custom_retrieve_fileproperties:
+            return self.custom_retrieve_fileproperties(name, path)
+        try:
+            m = regex_content.match(name)
+            if not m or not self.isattachment:
+                raise TypeError, 'Can\'t retrieve %s fileproperties' % name
+            filename = base64.b16decode(m.group('name'), True)
+            filename = regex_cleanup_fn.sub('_', filename)
+        except (TypeError, AttributeError):
+            filename = name
+        if isinstance(self.uploadfield, str):  # ## if file is in DB
+            return dict(path=None,filename=filename)
+        elif isinstance(self.uploadfield,Field):
+            return dict(path=None,filename=filename)
         else:
             # ## if file is on filesystem
             if path:
@@ -7652,7 +7670,8 @@ class Field(Expression):
                 f = m.group('field')
                 u = m.group('uuidkey')
                 path = os.path.join(path,"%s.%s" % (t,f),u[:2])
-            return (filename, open(os.path.join(path, name), 'rb'))
+            return dict(path=path,filename=filename)
+        
 
     def formatter(self, value):
         if value is None or not self.requires: