Made match mostly new template patterns

src/libs/event_system.py

@@ -0,0 +1,54 @@
+# Python imports
+from collections import defaultdict
+
+# Lib imports
+
+# Application imports
+from .singleton import Singleton
+
+
+
+class EventSystem(Singleton):
+    """ Create event system. """
+
+    def __init__(self):
+        self.subscribers = defaultdict(list)
+
+
+    def subscribe(self, event_type, fn):
+        self.subscribers[event_type].append(fn)
+
+    def unsubscribe(self, event_type, fn):
+        self.subscribers[event_type].remove(fn)
+
+    def unsubscribe_all(self, event_type):
+        self.subscribers.pop(event_type, None)
+
+    def emit(self, event_type, data = None):
+        if event_type in self.subscribers:
+            for fn in self.subscribers[event_type]:
+                if data:
+                    if hasattr(data, '__iter__') and not type(data) is str:
+                        fn(*data)
+                    else:
+                        fn(data)
+                else:
+                    fn()
+
+    def emit_and_await(self, event_type, data = None):
+        """ NOTE: Should be used when signal has only one listener and vis-a-vis """
+        if event_type in self.subscribers:
+            response = None
+            for fn in self.subscribers[event_type]:
+                if data:
+                    if hasattr(data, '__iter__') and not type(data) is str:
+                        response = fn(*data)
+                    else:
+                        response = fn(data)
+                else:
+                    response = fn()
+
+                if not response in (None, ''):
+                    break
+
+            return response