Refactor command implementation boilerplate into Command class

solvable/src/event_handler_main.py

@@ -1,3 +1,5 @@
+from re import match
+
 from tornado.ioloop import IOLoop
 
 from tfw.components import WebideEventHandler, TerminadoEventHandler, ProcessManagingEventHandler, BashMonitor
@@ -13,28 +15,53 @@ def cenator(history):
     MessageSender().send('JOHN CENA', 'You\'ve executed "{}"'.format(history[-1]))
 
 
-def selectdir(history):
-    try:
-        cmd = history[-1].split()
-        if cmd[0] == 'selectdir':
-            TFWServerConnector().send_to_eventhandler('webide',
-                                                      {'data': {'command': 'selectdir',
-                                                                'directory': cmd[1]}})
-    except IndexError:
-        LOG.exception('Selectdir failed!')
+class Commands:
+    def __init__(self):
+        self.command_impls = {self._parse_command_name(fun): getattr(self, fun) for fun in dir(self)
+                              if callable(getattr(self, fun))
+                              and self._is_command_implementation(fun)}
 
+    @staticmethod
+    def _is_command_implementation(method_name):
+        return bool(Commands._match_command_regex(method_name))
 
-def toggle_next(history):
-    toggle_next.button_state = not toggle_next.button_state
-    try:
-        cmd = history[-1].split()
-        if cmd[0] == 'togglenext':
-            TFWServerConnector().send('messagecontrol',
-                                      {'data': {'command': 'showbutton',
-                                                'next_visibility': toggle_next.button_state}})
-    except IndexError:
-        LOG.exception('Togglenext failed!')
-toggle_next.button_state = False
+    @staticmethod
+    def _parse_command_name(method_name):
+        try:
+            return Commands._match_command_regex(method_name).groups()[0]
+        except AttributeError:
+            return ''
+
+    @staticmethod
+    def _match_command_regex(string):
+        command_impl_regex = r'^_command_impl_(.+)$'
+        return match(command_impl_regex, string)
+
+    def callback(self, history):
+        parts = history[-1].split()
+        command = parts[0]
+        if command in self.command_impls.keys():
+            try:
+                self.command_impls[command](*parts[1:])
+            except IndexError:
+                LOG.debug('Command "%s" failed!', command)
+
+    def _command_impl_selectdir(self, *args):
+        TFWServerConnector().send_to_eventhandler('webide',
+                                                  {'data': {'command': 'selectdir',
+                                                            'directory': args[0]}})
+
+    def _command_impl_trigger(self, *args):
+        TFWServerConnector().send('selectdir_needs_no_key',
+                                  {'trigger': args[0]})
+
+    def _command_impl_togglenext(self, *args):
+        if not hasattr(self, 'togglenext_visible'):
+            self.togglenext_visible = True
+        TFWServerConnector().send('messagecontrol',
+                                  {'data': {'command': 'showbutton',
+                                            'next_visibility': self.togglenext_visible}})
+        self.togglenext_visible = not self.togglenext_visible
 
 
 if __name__ == '__main__':
@@ -43,8 +70,8 @@ if __name__ == '__main__':
                              directory=TFWENV.WEBIDE_WD, exclude=['*.pyc'])
     terminado = TerminadoEventHandler(key='shell', monitor=BashMonitor(TFWENV.HISTFILE))
     terminado.historymonitor.subscribe_callback(cenator)
-    terminado.historymonitor.subscribe_callback(selectdir)
-    terminado.historymonitor.subscribe_callback(toggle_next)
+    commands = Commands()
+    terminado.historymonitor.subscribe_callback(commands.callback)
     processmanager = ProcessManagingEventHandler(key='processmanager', dirmonitor=ide.monitor)
 
     eventhandlers = {ide, terminado, processmanager}