What are some advanced usage patterns for decorators in TypeScript?

What are some advanced usage patterns for decorators in TypeScript?

In TypeScript, decorators can be used for various advanced patterns like logging, validation, and access control. Would you like examples?

Yes, please provide an example of a logging decorator.

Sure! Here's a simple logging decorator:

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

This decorator logs the method name and its arguments before executing the method.

How can I use this logging decorator in a class?

You can use the logging decorator like this:

class Example {
    @Log
    someMethod(arg1: string, arg2: number) {
        // method implementation
    }
}

Now, whenever someMethod is called, it will log the arguments.

Can decorators be used for dependency injection?

Absolutely! Decorators can be used to mark classes for dependency injection, allowing frameworks to manage instances automatically.