🔧 Adding

Decorator Pattern

Author: raj713335

05 Structural Design Patterns/04 Decorator Design Pattern.py

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+# Define common Interface
+
+from abc import ABC, abstractmethod
+
+
+class Notifier(ABC):
+    @abstractmethod
+    def send(self, message: str):
+        ...
+
+
+# Implement the concreate Component (Basic Email Notification)
+
+class EmailNotifier(Notifier):
+    def send(self, message: str):
+        print(f"Sending EMAIL with message: {message}")
+
+
+# Create the Base Decorator
+
+class NotifierDecorator(Notifier):
+    def __init__(self, wrapper: Notifier):
+        self._wrapper = wrapper
+
+    def send(self, message: str):
+        self._wrapper.send(message)
+
+
+# Create Concreate Decorator (SMS, Slack, Facebook)
+
+class SMSNotifier(NotifierDecorator):
+    def send(self, message: str):
+        super().send(message)
+        self.send_sms(message)
+
+    def send_sms(self, message: str):
+        print(f"Sending SMS with message: {message}")
+
+
+class FacebookNotifier(NotifierDecorator):
+    def send(self, message: str):
+        super().send(message)
+        self.send_facebook(message)
+
+    def send_facebook(self, message: str):
+        print(f"Sending Facebook with message: {message}")
+
+
+class SlackNotifier(NotifierDecorator):
+    def send(self, message: str):
+        super().send(message)
+        self.send_slack(message)
+
+    def send_slack(self, message: str):
+        print(f"Sending Slack with message: {message}")
+
+
+# Client Code (Runtime composition with Decorators)
+
+if __name__ == "__main__":
+    # Basic notifier (email only)
+    notifier = EmailNotifier()
+
+    # wrap with SMS and Slack decorators
+    notifier = SMSNotifier(notifier)
+    notifier = SlackNotifier(notifier)
+    notifier = FacebookNotifier(notifier)
+
+    # Client Sends one message - it flows through all decorators
+    notifier.send("Alert: Server CPU usage exceeded 90% threshold")
+
+
+# Addition of numbers using a decorators
+
+def sumx(func):
+    def wrapper(*args, **kwargs):
+        result = sum(args)
+        return func(result, **kwargs)
+    return wrapper
+
+@sumx
+def sum_numbers(result):
+    return f"Sum of numbers is: {result}"
+
+print(sum_numbers(1, 3, 4, 8, 9))