fos

Description:

fos

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));
}
}
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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);
}
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Auto converting Exceptions to Failures #
You can convert exceptions to failures using the Fos.toFailure(exception) method.
This method takes an exception as input and returns the corresponding failure if it is mapped in the errors . Here's how you can use it:
/// Dont forget to create yours custom exception and Failure
final errors = {
Custom1Exception(): Custom1Failure(),
Custom2Exception(): Custom2Failure(),
}
Fos.initErrors(error);
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*After
try {
final user = await someFunction();
return Fos.success(user);
} catch (e) {
return Fos.toFailure(e);
}
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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
}
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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
},
);
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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,
});
}
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** custom failure**
class MyCustomFailure extends Failure {
const MyCustomFailure({
super.message,
super.code,
});
}
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Initialization #
Before using FOS, you can initialize custom errors using the initErrors method:
dartCopy code
`Fos.initErrors({
Custom1Exception(): Custom1Failure(),
Custom2Exception(): Custom2Failure(),
});`
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or
Add errors to the existing errors.
static addErrors(Map<Object, Failure> errors) {
_errors.addAll({Custom2Exception(): Custom2Failure()});
}
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