Refactored the updates routing

Routing for updates (updates containing messages are processed by a
specific hook, updates with callbacks by another...) is now fully
customizable.

This allows for more modularity, as well to add processing logic for
more updates kinds easily.

Author: Pietro Albini

botogram/bot.py

@@ -21,6 +21,7 @@
 from . import frozenbot
 from . import shared
 from . import tasks
+from . import messages
 
 
 class Bot(frozenbot.FrozenBot):
@@ -63,6 +64,10 @@ def __init__(self, api_connection):
         # Setup the scheduler
         self._scheduler = tasks.Scheduler()
 
+        # Initialize the list of update processors
+        self._update_processors = {}
+        self.register_update_processor("message", messages.process_message)
+
         self._bot_id = str(uuid.uuid4())
 
         self.use(defaults.DefaultComponent())
@@ -191,6 +196,14 @@ def run(self, workers=2):
         inst = runner.BotogramRunner(self, workers=workers)
         inst.run()
 
+    def register_update_processor(self, kind, processor):
+        """Register a new update processor"""
+        if kind in self._update_processors:
+            raise NameError("An update processor for \"%s\" updates is "
+                            "already registered" % kind)
+
+        self._update_processors[kind] = processor
+
     def freeze(self):
         """Return a frozen instance of the bot"""
         chains = components.merge_chains(self._main_component,
@@ -202,7 +215,8 @@ def freeze(self):
                                    self.lang, self.itself, self._commands_re,
                                    self._commands, chains, self._scheduler,
                                    self._main_component._component_id,
-                                   self._bot_id, self._shared_memory)
+                                   self._bot_id, self._shared_memory,
+                                   self._update_processors)
 
     @property
     def lang(self):

botogram/frozenbot.py

@@ -23,7 +23,7 @@ class FrozenBot:
     def __init__(self, api, about, owner, hide_commands, before_help,
                  after_help, process_backlog, lang, itself, commands_re,
                  commands, chains, scheduler, main_component_id, bot_id,
-                 shared_memory):
+                 shared_memory, update_processors):
         # This attribute should be added with the default setattr, because is
         # needed by the custom setattr
         object.__setattr__(self, "_frozen", False)
@@ -43,6 +43,7 @@ def __init__(self, api, about, owner, hide_commands, before_help,
         self._shared_memory = shared_memory
         self._scheduler = scheduler
         self._chains = chains
+        self._update_processors = update_processors
         self._commands = {name: command.for_bot(self)
                           for name, command in commands.items()}
 
@@ -65,7 +66,7 @@ def __reduce__(self):
             self.before_help, self.after_help, self.process_backlog,
             self.lang, self.itself, self._commands_re, self._commands,
             self._chains, self._scheduler, self._main_component_id,
-            self._bot_id, self._shared_memory,
+            self._bot_id, self._shared_memory, self._update_processors,
         )
         return restore, args
 
@@ -171,21 +172,13 @@ def process(self, update):
         update.set_api(self.api)  # Be sure to use the correct API object
 
         try:
-            for hook in self._chains["messages"]:
-                # Get the correct name of the hook
-                name = hook.name
-                self.logger.debug("Processing update #%s with the %s hook..." %
-                                  (update.update_id, name))
-
-                result = hook.call(self, update)
-                if result is True:
-                    self.logger.debug("Update #%s was just processed by the "
-                                      "%s hook." % (update.update_id, name))
-                    return True
-
-            self.logger.debug("No hook actually processed the #%s update." %
-                              update.update_id)
+            for kind, processor in self._update_processors.items():
+                # Call the processor of the right kind
+                if getattr(update, kind) is None:
+                    continue
 
+                processor(self, self._chains, update)
+                break
         except api_module.ChatUnavailableError as e:
             # Do some sane logging
             self.logger.warning("Chat %s is not available to your bot:" %
@@ -199,8 +192,6 @@ def process(self, update):
                                   e.chat_id))
                 hook.call(self, e.chat_id, e.reason)
 
-        return False
-
     def scheduled_tasks(self, current_time=None, wrap=True):
         """Return a list of tasks scheduled for now"""
         # This provides a better API for the users of the method
@@ -215,6 +206,10 @@ def process():
             return [wrapper(job) for job in tasks]
         return list(tasks)
 
+    def register_update_processor(self, kind, processor):
+        """Register a new update processor"""
+        raise FrozenBotError("Can't register new update processors at runtime")
+
     # This helper manages the translation
 
     def _(self, message, **args):

botogram/messages.py

@@ -0,0 +1,23 @@
+"""
+    botogram.messages
+    Logic for processing messages sent to your bot
+
+    Copyright (c) 2016 Pietro Albini <[email protected]>
+    Released under the MIT license
+"""
+
+
+def process_message(bot, chains, update):
+    """Process a message sent to the bot"""
+    for hook in chains["messages"]:
+        bot.logger.debug("Processing update #%s with the hook %s..." %
+                         (update.update_id, hook.name))
+
+        result = hook.call(bot, update)
+        if result is True:
+            bot.logger.debug("Update #%s was just processed by the %s hook." %
+                             (update.update_id, hook.name))
+            return
+
+    bot.logger.debug("No hook actually processed the #%s update." %
+                     update.update_id)