Changes between Version 2 and Version 3 of TracDev/Proposals/AdvancedNotification/INotificationFormatter

Timestamp:

Oct 12, 2013, 12:29:01 AM (11 years ago)

Author:

Peter Suter

Comment:

Raise question of how to get at all supported styles.

TracDev/Proposals/AdvancedNotification/INotificationFormatter

@@ -39 +39 @@
     def styles(self, transport, realm):
         if transport == 'sms' and realm == 'ticket':
-            yield 'text/plain and short'
+            yield 'text/plain'
 
     def format(self, transport, style, event):
@@ -64 +64 @@
    * DONE Dropped the `alternative_style_for()` method. (The distributor can select fallbacks without this.)
    * DONE Dropped the `realm` parameter to the `format()` method. (Use `event.realm` instead.)
+
+== Open questions
+
+=== Enumerate all styles?
+Maybe `styles()` should be changed to enumerate the supported style / transport / realm combinations as tuples:
+{{{#!python
+    def styles(self):
+        yield ('text/plain', 'sms', 'ticket')
+}}}
+
+Advantage: This would give access to the list of all supported styles, without guessing the supported realms. For example a preferences panel could then create a ''preferred style'' selection UI, listing all supported styles.
+
+Disadvantage: Formatters could not implement catch-all fallbacks that e.g. claim to support all transports. But all current Announcer formatters do just this.
+
+Possible solutions:
+* ''Do not allow'' formatters to support all transports. Is that actually even feasible? The formatter interface even states that it must be explicitly designed to work with a specific distributor.
+* ''Require'' all formatters to support all transports. Remove the transports parameter. This would prevent using different formatters for different transports. (At least the return type of `format()` could then probably be defined to some standardized type.)
+* ''Allow'' formatters to return `None` or `'*'` to support all transports.
+* Define the interface with ''two methods''. One method with parameters as before; another method without parameters must list all supported styles for any transport or realm.
+* Define the interface with one method, with ''optional parameters''. If the parameters are `None` the method must list all supported styles for any transport or realm.
+
+Similary, could some formatters want to support all realms?
+
+The chosen solution should be simple and easy to implement correctly by plugin authors.