How do I implement decorators in TypeScript?

Can you explain how to implement decorators in TypeScript?

Sure! Decorators in TypeScript are special functions that can modify classes, methods, or properties. They are prefixed with the @ symbol.

What are some common use cases for decorators?

Common use cases include logging, access control, and validation. For example, you can create a logging decorator to log method calls.

How do I create a simple method decorator?

You can create a method decorator by defining a function that takes the target, property key, and descriptor as parameters. Then, you can modify the descriptor as needed.

Can you show me a code example?

Absolutely! Here's a simple example:

function Log(target: any, propertyKey: string, descriptor: PropertyDescriptor) {
    const originalMethod = descriptor.value;
    descriptor.value = function(...args: any[]) {
        console.log(`Calling ${propertyKey} with args: ${args}`);
        return originalMethod.apply(this, args);
    };
}

class Example {
    @Log
    sayHello(name: string) {
        return `Hello, ${name}!`;
    }
}