If you miss an extension, please open an issue or pull request
On this page you can find some of the extensions. Take a look at the docs to see all of them.
Add the following to your pubspec.yaml
:
dependencies:
dartx:
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, 4]
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]
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
Get distinct elements from a list.
var list = ['this', 'is', 'a', 'test'];
var distinctByLength = list.distinctBy((it) => it.length); // ['this', 'is', 'a']
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]
Chunk entries as long as long as two elements match a predicate:
final list = [1, 2, 4, 9, 10, 11, 12, 15, 16, 19, 20, 21];
final increasingSubSequences = list.chunkWhile((a, b) => a + 1 == b);
// increasingSubSequences = [[1, 2], [4], [9], [10, 11, 12], [15, 16], [19, 20, 21]]
splitWhen
is the opposite of chunkWhile
that starts a new chunk every time
the predicate didn't match.
Get a list of single character strings from a string. Supports emojis.
var chars = 'family๐จโ๐จโ๐งโ๐ฆ'.chars; // ['f', 'a', 'm', 'i', 'l', 'y', '๐จโ๐จโ๐งโ๐ฆ']
Returns true
if this string is empty or consists solely of whitespace characters.
var notBlank = ' .'.isBlank; // false
var blank = ' '.isBlank; // true
Parses the string as an integer or returns null
if it is not a number.
var number = '12345'.toIntOrNull(); // 12345
var notANumber = '123-45'.toIntOrNull(); // null
Remove a prefix, a suffix, or both from a given string:
var name = 'James Bond'.removePrefix('James '); // Bond
var milliseconds = '100ms'.removeSuffix('ms'); // 100
var text = '<p>Some HTML</p>'
.removeSurrounding(prefix: '<p>', suffix: '</p>'); // Some HTML
Dartx exports @jogboms great โฐ time.dart package so you can do the following:
int secondsInADay = 1.days.inSeconds;
Duration totalTime = [12.5.seconds, 101.milliseconds, 2.5.minutes].sum();
DateTime oneWeekLater = DateTime.now() + 1.week;
Check out โฐ time.dart for more information and examples.
Ensures that this value lies in the specified range.
var numberInRange = 123.coerceIn(0, 1000); // 123
var numberOutOfRange = -123.coerceIn(0, 1000); // 0
Converts this value to binary form.
Creates a range between two ints (upwards, downwards and with custom steps)
// upwards with default step size 1
for (var i in 1.rangeTo(5)) {
print(i); // 1, 2, 3, 4, 5
}
// downwards with custom step
for (var i in 10.rangeTo(2).step(2)) {
print(i); // 10, 8, 6, 4, 2
}
Use call()
instead. This is very useful for null
checks.
var func = (String value) {
print(value);
}
func?.call('hello world');
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!
Get the name and extension of a file.
var file = File('some/path/testFile.dart');
print(file.name); // testFile.dart
print(file.nameWithoutExtension); // testFile
Append text to a file.
await File('someFile.json').appendText('{test: true}');
Checks if a file is inside a directory.
var dir = Directory('some/path');
File('some/path/file.dart').isWithin(dir); // true
Checks if a Directory
contains a FileSystemEntity
. This can be a File
or a Directory
.
Use the recursive
argument to include the subdirectories.
final File someFile = File('someFile.txt');
final Directory someDir = Directory('some/dir');
final Directory parentDir = Directory('parent/dir');
parentDir.contains(someFile);
parentDir.contains(someDir);
parentDir.contains(someFile, recursive: true);
parentDir.contains(someDir, recursive: true);
This is the async
method, which returns a Future<bool>
.
Same as .contains(FileSystemEntity entity, {bool recursive = false})
but synchronous. Returns a bool
.
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.