fos 0.0.4

handling error

FOS (Failure or Success) - Dart Package

FOS is a Dart package designed to help you handle errors and successes in your applications in a structured and manageable way. It provides a mechanism for encapsulating both failures and successes, making error handling cleaner and more consistent across your codebase.

Features

• ** ✅ Structured Error Handling**: FOS provides a structured way to handle errors and successes, making your code more readable and maintainable.
• ** ✅ Custom Error Handling**: You can define custom error types and map them to specific exceptions or error conditions in your application.
• ** ✅ Consistent API**: FOS ensures a consistent API for handling both failures and successes, simplifying error management across your codebase.

Usage

Handling Failures

To return a failure, use the Fos.failure(MyFailure()) factory method:

Success<UserEntity> findUser({String? params}) async {  
   try {  
     final user = await someFunction();
     return Fos.success(user);  
   }  on SerializationException {  
	 return Fos.failure(SerializationFailure(message:"xxxx"));  
   } on ServerException {
     return Fos.failure(ServerFailure(message: "xxxx",code: 500));  
   }
}

Handling Successes

To return a success, use the Fos.success(MyObject) factory method:

try {
  final user = await someFunction();
  return Fos.success(user);
} catch (e) {
  return Fos.toFailure(e);
}

Checking Result Status

You can check whether the result is a failure or success using the isFailure and isSuccess properties:

final result = await someFunction();
if (result.isFailure) {
  // Handle failure
} else {
  // Handle success
}

Handling Results

You can handle both failure and success using the on method:

final result = await someFunction();
result.on(
  (failure) {
    // Handle failure
  },
  (success) {
    // Handle success
  },
);

Custom Errors

You can define custom error types by extending the Failure , Exceptions class and providing your own implementation:

custom exception

 class MyCustomException extends Exceptions {  
	  const ServerException({  
	     super.message,  
		 super.error,  
	  });  
 }

** custom failure**

  class MyCustomFailure extends Failure {  
	      const MyCustomFailure({  
		        super.message,  
		        super.code,  
	       });  
  }

Initialization

Before using FOS, you can initialize custom errors using the initErrors method:

dartCopy code

`Fos.initErrors({
  Custom1Exception(): Custom1Failure(),
  Custom2Exception(): Custom2Failure(),
});`

or Add errors to the existing errors.

static addErrors(Map<Object, Failure> errors) {  
  _errors.addAll({Custom2Exception(): Custom2Failure()});  
}