DF - Type
Dart & Flutter Packages by DevCetra.com & contributors.
Summary
A package designed to simplify and enhance interactions with Dart types. It provides tools for converting between types, checking type properties, and managing synchronous and asynchronous operations. For a full feature set, please refer to the API reference.
Quickstart
enum Alphabet { A, B, C }
void main() async {
print('Convert a String to an enum:\n');
print(Alphabet.values.valueOf('A') == Alphabet.A); // true
print(Alphabet.values.valueOf('a') == Alphabet.A); // true
print(Alphabet.values.valueOf('b')); // Alphabet.B
print(Alphabet.values.valueOf('qwerty') == null); // true
print('\n*** Check if a type is nullable:\n');
print(isNullable<String>()); // false
print(isNullable<String?>()); // true
print(isNullable<Null>()); // true
print('\n*** Check if a type a subtype of another::\n');
print(isSubtype<int, num>()); // true
print(isSubtype<num, int>()); // false
print(isSubtype<Future<int>, Future<dynamic>>()); // true
print(isSubtype<Future<dynamic>, Future<int>>()); // false
print(isSubtype<int Function(int), Function>()); // true
print(isSubtype<Function, int Function(int)>()); // false
print('\n*** Check if a type can be compared by value:\n');
print(isEquatable<double>()); // true
print(isEquatable<Null>()); // true
print(isEquatable<Map<dynamic, dynamic>>()); // false
print(isEquatable<Equatable>()); // true
print('\n*** Only let a value be of a certain type, or return null:\n');
print(letAsOrNull<String>(DateTime.now())); // null
print(letAsOrNull<DateTime>(DateTime.now())); // returns the value
print(letAsOrNull<DateTime?>(DateTime.now())); // returns the value
print(letAsOrNull<DateTime?>(null)); // null
print('\n*** Lazy-convert types to an int or return null:\n');
final int? i = letIntOrNull('55');
print(i); // 55
print('\n*** Lazy-convert maps from one type to another or return null:\n');
final Map<String, int>? m = letMapOrNull<String, int>({55: '56'});
print(m); // {55, 56}
print('\n*** Lazy-convert lists or return null:\n');
print(letListOrNull<int>('1, 2, 3, 4')); // [1, 2, 3, 4]
print(letListOrNull<int>('[1, 2, 3, 4]')); // [1, 2, 3, 4]
print(letListOrNull<int>([1, 2, 3, 4])); // [1, 2, 3, 4]
print(letListOrNull<int>(1)); // [1]
print('\n*** Lazy-convert to double or return null:\n');
print(letOrNull<double>('123')); // 123.0
print('\n*** Convert a String to a Duration:\n');
final Duration duration = const ConvertStringToDuration('11:11:00.00').toDuration();
print(duration); // 11:11:00.000000
print('\n*** Use thenOr with FutureOr:\n');
print(1.thenOr((prev) => prev + 1)); // 2
FutureOr<double> pi = 3.14159;
final doublePi = pi.thenOr((prev) => prev * 2);
print(doublePi); // 6.2832
FutureOr<double> e = Future.value(2.71828);
final doubleE = e.thenOr((prev) => prev * 2);
print(doubleE); // Instance of 'Future<double>'
print(await doubleE); // 5.43656
print('\n*** Manage Futures or values via FutureOrController:\n');
final a1 = Future.value(1);
final a2 = 2;
final a3 = Future.value(3);
final foc1 = FutureOrController<dynamic>([(_) => a1, (_) => a2, (_) => a3]);
final f1 = foc1.completeWithAll();
print(f1 is Future); // true
print(await f1); // [1, 2, 3]
final b1 = 1;
final b2 = 2;
final b3 = 2;
final foc2 = FutureOrController<dynamic>([(_) => b1, (_) => b2, (_) => b3]);
final f2 = foc2.completeWithAll();
print(f2 is Future); // false
print(f2); // [1, 2, 3]
print('\n*** CompleterOr works with async or sync values:\n');
final completer1 = CompleterOr<int>();
completer1.complete(1);
final c1 = completer1.futureOr;
print(c1 is Future); // false
final completer2 = CompleterOr<int>();
completer2.complete(Future.value(1));
final c2 = completer2.futureOr;
print(c2 is Future); // true
// The ExecutionQueue guarantees that functions will execute in the same
// order as they are added:
print('\n*** Test function queue:\n');
final executionQueue = ExecutionQueue();
executionQueue.add((prev) async {
print('Previous: $prev');
print('Function 1 running');
await Future<void>.delayed(const Duration(seconds: 3));
print('Function 1 completed');
return 1;
});
executionQueue.add((prev) async {
print('Previous: $prev');
await Future<void>.delayed(const Duration(seconds: 2));
print('Function 2 completed');
return 2;
});
executionQueue.add((prev) async {
print('Previous: $prev');
await Future<void>.delayed(const Duration(seconds: 1));
print('Function 3 completed');
return 3;
});
await executionQueue.add((prev) async {
print('Previous: $prev');
await Future<void>.delayed(const Duration(seconds: 1));
print('Function 3 completed');
});
// Prints:
// Function 1 running
// Function 1 completed
// Function 2 running
// Function 2 completed
// Function 3 running
// Function 3 completed
print(executionQueue.add((_) => 'Hello').runtimeType); // String
print(executionQueue.add((prev) => '$prev World!')); // Hello World!
}
Installation
Use this package as a dependency by adding it to your pubspec.yaml file (see here).
Contributing and Discussions
This is an open-source project, and we warmly welcome contributions from everyone, regardless of experience level. Whether you're a seasoned developer or just starting out, contributing to this project is a fantastic way to learn, share your knowledge, and make a meaningful impact on the community.
Ways you can contribute:
- Buy me a coffee: If you'd like to support the project financially, consider buying me a coffee. Your support helps cover the costs of development and keeps the project growing.
- Share your ideas: Every perspective matters, and your ideas can spark innovation.
- Report bugs: Help us identify and fix issues to make the project more robust.
- Suggest improvements or new features: Your ideas can help shape the future of the project.
- Help clarify documentation: Good documentation is key to accessibility. You can make it easier for others to get started by improving or expanding our documentation.
- Write articles: Share your knowledge by writing tutorials, guides, or blog posts about your experiences with the project. It's a great way to contribute and help others learn.
No matter how you choose to contribute, your involvement is greatly appreciated and valued!
Chief Maintainer:
📧 Email Robert Mollentze at robmllze@gmail.com
Dontations:
If you're enjoying this package and find it valuable, consider showing your appreciation with a small donation. Every bit helps in supporting future development. You can donate here:
https://www.buymeacoffee.com/robmllze
License
This project is released under the MIT License. See LICENSE for more information.
Libraries
- df_type
- A package designed to simplify and enhance interactions with Dart types.