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: any
After you import the library, you can use the extensions.
import 'package:dartx/dartx.dart';
final slice = [1, 2, 3, 4, 5].slice(1, -2); // [2, 3, 4]
Returns elements at indices between start
(inclusive) and end
(inclusive).
final list = [0, 1, 2, 3, 4, 5];
final last = list.slice(-1); // [5]
final lastHalf = list.slice(3); // [3, 4, 5]
final allButFirstAndLast = list.slice(1, -2); // [1, 2, 3, 4]
Sort lists by multiple properties.
final 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),
];
final sorted = dogs
.sortedBy((dog) => dog.name)
.thenByDescending((dog) => dog.age);
// Bark, Cookie, Charlie (7), Charlie (2), Tom
Get distinct elements from a list.
final list = ['this', 'is', 'a', 'test'];
final distinctByLength = list.distinctBy((it) => it.length); // ['this', 'is', 'a']
Get a new lazy Iterable
of all elements from all collections in a collection.
final nestedList = [[1, 2, 3], [4, 5, 6]];
final flattened = nestedList.flatten(); // [1, 2, 3, 4, 5, 6]
Chunk entries 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.
Builds new string by populating newly created StringBuffer
using provided builderAction
and then converting it to String
.
final word = buildString((sb) {
for (var i = 0; i < 10; i++) {
sb.write(i);
}
});
// 0123456789
Returns an ordinal number of String
type for any integer
final a = 1.ordinal(); // 1st
final b = 108.ordinal(); // 108th
Returns a copy of the string having its first letter uppercased, or the original string, if it's empty or already starts with an upper case letter.
final word = 'abcd'.capitalize(); // Abcd
final anotherWord = 'Abcd'.capitalize(); // Abcd
Returns a copy of the string having its first letter lowercased, or the original string, if it's empty or already starts with a lower case letter.
final word = 'abcd'.decapitalize(); // abcd
final anotherWord = 'Abcd'.decapitalize(); // abcd
Returns true
if the string is ASCII encoded.
final isAscii = 'abc123 !,.~'.isAscii; // true
final isNotAscii = 'Β§3'.isAscii; // false
Returns true
if this string is empty or consists solely of whitespace characters.
final notBlank = ' .'.isBlank; // false
final blank = ' '.isBlank; // true
Returns true
if the string can be parsed as a double.
final a = ''.isDouble; // false
final b = 'a'.isDouble; // false
final c = '1'.isDouble; // true
final d = '1.0'.isDouble; // true
final e = '123456789.987654321'.isDouble; // true
final f = '1,000'.isDouble; // false
Returns true
if the string can be parsed as an integer.
final a = ''.isInt; // false
final b = 'a'.isInt; // false
final c = '1'.isInt; // true
final d = '1.0'.isInt; // false
final e = '1,000'.isInt; // false
Returns true
if the string is Latin 1 encoded.
final isLatin1 = 'Β§ΓΓΌ'.isLatin1; // true
final isNotLatin1 = 'Ε'.isLatin1; // false
Returns true
if the entire string is lower case.
final a = 'abc'.isLowerCase; // true
final b = 'abC'.isLowerCase; // false
final c = ' '.isLowerCase; // true
final d = ''.isLowerCase; // false
Returns true
if this string is not empty and contains characters except whitespace characters.
final blank = ' '.isNotBlank; // false
final notBlank = ' .'.isNotBlank; // true
Returns true
if the String is either null
or empty.
final isNull = null.isNullOrEmpty; // true
final isEmpty = ''.isNullOrEmpty; // true
final isBlank = ' '.isNullOrEmpty; // false
final isLineBreak = '\n'.isNullOrEmpty; // false
Returns true
if the String is neither null
nor empty.
final isNull = null.isNullOrEmpty; // true
final isEmpty = ''.isNullOrEmpty; // true
final isBlank = ' '.isNullOrEmpty; // false
final isLineBreak = '\n'.isNullOrEmpty; // false
Returns true
if the String is either null
or blank.
final isNull = null.isNullOrBlank; // true
final isEmpty = ''.isNullOrBlank; // true
final isBlank = ' '.isNullOrBlank; // true
final isLineBreak = '\n'.isNullOrBlank; // true
final isFoo = ' foo '.isNullOrBlank; // false
Returns true
if the String is neither null
nor blank.
final isNull = null.isNullOrBlank; // true
final isEmpty = ''.isNullOrBlank; // true
final isBlank = ' '.isNullOrBlank; // true
final isLineBreak = '\n'.isNullOrBlank; // true
final isFoo = ' foo '.isNullOrBlank; // true
Returns true
if the entire string is upper case.
final a = 'ABC'.isUpperCase; // true
final b = 'ABc'.isUpperCase; // false
final c = ' '.isUpperCase; // true
final d = ''.isUpperCase; // false
Calculates the MD5 digest and returns the value as a string of hexadecimal digits.
final a = 'abc'.md5; // 900150983cd24fb0d6963f7d28e17f72
final b = 'ΰ΄βο€Ππ¨βπ¨βπ§βπ¦'.md5; // c7834eff7c967101cfb65b8f6d15ad46
Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme.
const originalUrl = 'Hello Ladies + Gentlemen, a signed OAuth request!';
final encodedUrl = originalUrl.urlEncode;
// 'Hello%20Ladies%20+%20Gentlemen,%20a%20signed%20OAuth%20request!'
Decodes an application/x-www-form-urlencoded string using a specific encoding scheme.
const encodedUrl = 'Hello%20Ladies%20+%20Gentlemen,%20a%20signed%20OAuth%20request!';
final decodedUrl = encodingUrl.urlDecode;
// 'Hello Ladies + Gentlemen, a signed OAuth request!'
Remove a prefix, a suffix, or both from a given string:
final name = 'James Bond'.removePrefix('James '); // Bond
final milliseconds = '100ms'.removeSuffix('ms'); // 100
final text = '<p>Some HTML</p>'
.removeSurrounding(prefix: '<p>', suffix: '</p>'); // Some HTML
Returns a new string with characters in reversed order.
final emptyString = ''.reversed; // ''
final reversed = 'abcπ€'.reversed; // 'π€cba'
Returns a new substring containing all characters including indices [start] and [end].
If [end] is omitted, it is being set to lastIndex
.
final sliceOne = 'awesomeString'.slice(0,6)); // awesome
final sliceTwo = 'awesomeString'.slice(7)); // String
Parses the string as a double
and returns the result or null
if the String is not a valid representation of a number.
final numOne = '1'.toDoubleOrNull(); // 1.0
final numTwo = '1.2'.toDoubleOrNull(); // 1.2
final blank = ''.toDoubleOrNull(); // null
Parses the string as an integer and returns the result. The radix (base) thereby defaults to 10. Throws a FormatException
if parsing fails.
final a = '1'.toInt(); // 1
final b = '100'.toInt(radix: 2); // 4
final c = '100'.toInt(radix: 16); // 256
final d = '1.0'.toInt(); // throws FormatException
Parses the string as an integer or returns null
if it is not a number.
final number = '12345'.toIntOrNull(); // 12345
final notANumber = '123-45'.toIntOrNull(); // null
Converts String to UTF-8 encoding.
final emptyString = ''.toUtf8(); // []
final hi = 'hi'.toUtf8(); // [104, 105]
final emoji = 'π'.toUtf8(); // [240, 159, 152, 132]
Converts String to UTF-16 encoding.
final emptyString = ''.toUtf16(); // []
final hi = 'hi'.toUtf16(); // [104, 105]
final emoji = 'π'.toUtf16(); // [55357, 56836]
Returns the string if it is not null
, or the empty string otherwise.
String? nullableStr;
final str = nullableStr.orEmpty(); // ''
Returns true
if this char sequence matches the given regular expression.
print('as'.matches(RegExp('^.s\$'))) // true
print('mst'.matches(RegExp('^.s\$'))) // false
Dartx exports @jogboms great β° 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 β° time.dart for more information and examples.
Ensures that this value lies in the specified range.
final numberInRange = 123.coerceIn(0, 1000); // 123
final numberOutOfRange = -123.coerceIn(0, 1000); // 0
Converts this value to binary form.
Converts this value to character
final character = 97.toChar(); // a
Creates a range between two ints (upwards, downwards and with custom steps)
// upwards with default step size 1
for (final i in 1.rangeTo(5)) {
print(i); // 1, 2, 3, 4, 5
}
// downwards with custom step
for (final i in 10.rangeTo(2).step(2)) {
print(i); // 10, 8, 6, 4, 2
}
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!');
}
final greetStark = greet.partial('Stark');
greetStark('Sansa'); // Hi Sansa Stark!
greetStark('Tony'); // Hi Tony Stark!
Get the name and extension of a file.
final 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.
final dir = Directory('some/path');
File('some/path/file.dart').isWithin(dir); // true
References a file within a Directory
Directory androidDir = Directory('flutter-app/android');
File manifestFile = androidDir.file("app/src/main/AndroidManifest.xml");
References a directory within a Directory
Directory androidDir = Directory('flutter-app/android');
Directory mainSrc = androidDir.directory("app/src/main");
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.