tchigher / dartx

Superpowers for Dart. Collection of useful static extension methods.

If you miss an extension, please open an issue or pull request

Resources:

• Documentation
• Pub Package
• GitHub Repository

On this page you can find some of the extensions. Take a look at the docs to see all of them.

Getting started 🎉

Add the following to you pubspec.yaml and replace [version] with the latest version:

dependencies:
  dartx: ^[version]

After you import the library, you can use the extensions.

import 'package:dartx/dartx.dart';

var slice = [1, 2, 3, 4, 5].slice(1, -2); // [2, 3]

Iterable

slice()

Returns elements at indices between start (inclusive) and end (inclusive).

var list = [0, 1, 2, 3, 4, 5];
var last = list.slice(-1); // [5]
var lastHalf = list.slice(3); // [3, 4, 5]
var allButFirstAndLast = list.slice(1, -2); // [1, 2, 3, 4]

sortedBy() & thenBy()

Sort lists by multiple properties.

var dogs = [
  Dog(name: "Tom", age: 3),
  Dog(name: "Charlie", age: 7),
  Dog(name: "Bark", age: 1),
  Dog(name: "Cookie", age: 4),
  Dog(name: "Charlie", age: 2),
];

var sorted = dogs
    .sortedBy((dog) => dog.name)
    .thenByDescending((dog) => dog.age);
// Bark, Cookie, Charlie (7), Charlie (2), Tom

distinctBy()

Get distinct elements from a list.

var list = ['this', 'is', 'a', 'test'];
var distinctByLength = list.distinctBy((it) => it.length); // ['this', 'is', 'a']

flatten()

Get a new lazy Iterable of all elements from all collections in a collection.

var nestedList = [[1, 2, 3], [4, 5, 6]];
var flattened = nestedList.flatten(); // [1, 2, 3, 4, 5, 6]

String

chars

Get a list of single character strings from a string. Supports emojis.

var chars = 'family👨‍👨‍👧‍👦'.chars; // ['f', 'a', 'm', 'i', 'l', 'y', '👨‍👨‍👧‍👦']

isBlank()

Returns true if this string is empty or consists solely of whitespace characters.

var notBlank = '   .'.isBlank; // false
var blank = '  '.isBlank; // true

toIntOrNull()

Parses the string as an ineger or returns null if it is not a number.

var number = '12345'.toIntOrNull(); // 12345
var notANumber = '123-45'.toIntOrNull(); // null

Function

invoke()

Executes a function. This is very useful for null checks.

var func = (String value) {
  print(value);
}

func?.invoke('hello world');

partial(), partial2() ...

Applies some of the required arguments to a function and returns a function which takes the remaining arguments.

void greet(String firstName, String lastName) {
  print('Hi $firstName $lastName!');
}

var greetStark = greet.partial('Stark');
greetStark('Sansa'); // Hi Sansa Stark!
greetStark('Tony'); // Hi Tony Stark!

File

name

Get the name and extension of a file.

var file = File('some/path/testFile.dart');
print(file.name); // testFile.dart
print(file.nameWithoutExtension); // testFile

appendText()

Append text to a file.

await File('someFile.json').appendText('{test: true}');

isWithin()

Checks if a file is inside a directory.

var dir = Directory('some/path');
File('some/path/file.dart').isWithin(dir); // true

License

Copyright 2019 Simon Leier

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.