- Sliver extensions
Why Method Extensions? When you’re using someone else’s API or when you implement a library that’s widely used, it’s often impractical or impossible to change the API. But you might still want to add some functionality.
let me know if you want something specific or you found a bug at bar.idan@gmail.com
- Go to
pubspec.yaml - add a dart_extensions and replace
[version]with the latest version:
dependencies:
dart_extensions: ^[version]- click the packages get button or flutter pub get
Very common way to calculate size in percentage is using the MediaQuery like so:
MediaQuery.of(context).size.width * 0.1Flatten a nested Map into a single level map
response.flatJson({
'key1': {'keyA': 'valueI'},
'key2': {'keyB': 'valueII'},
'key3': {
'a': {
'b': {'c': 2}
}
}
});
The result you can also specify max depth, its the maximum number of nested objects to flatten.// { // ‘key1.keyA’: ‘valueI’, // ‘key2.keyB’: ‘valueII’, // ‘key3.a.b.c’: 2 // };
Instead of the boilerplate we can use this awesome extension and get the same results.
Wrap your Application with:
ResponsiveApp(
builder: (BuildContext context, Orientation orientation, DeviceType deviceType) {
return YourAppWidget()
)AnimatedList(
key: chatListKey,
reverse: true,
padding: EdgeInsets.only(top: 10.textSizeResponsive),
shrinkWrap: true,Also the text should be responsive, no problem
Text(
'Note added by ${message.from ?? ''}',
style: avanirBook.copyWith(fontSize: 8.responsiveText),
),Returns true if at least one element matches the given predicate.
final users = [User(22, "Kasey"), User(23, "Jadn")];
users.any((u) => u.name == 'Kasey') // trueGroups the elements in values by the value returned by key.
final users = [User(22, "Kasey"), User(23, "Jadn"), User(22, "Rene"), User(32, "Aden")];
users.groupBy((u) => u.age); Sort the users by age:
{
22: [User:22, Kasey, User:22, Rene],
23: [User:23, Jadn],
32: [User:32, Aden]
}Sorts elements in the array in-place according to natural sort order of the value returned by specified selector function.
final users = [User(22, "Kasey"), User(16, "Roni"), User(23, "Jadn")];
users.sortBy((u) => u.age) /// [User(16, "Roni"), [User(22, "Kasey"), User(23, "Jadn")]Returns the first element matching the given predicate, or null if element wasn’t found.
final users = [User(22, "Kasey"), User(23, "Jadn"), User(22, "Rene"), User(32, "Aden")];
users.find((u) => u.name == "Rene") // User(22, "Rene")Splits the Iterable into chunks of the specified size
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10].chunks(3)) result
([1, 2, 3], [4, 5, 6], [7, 8, 9], [10])Returns a list containing only elements matching the given predicate, the return type will be List,
unlike the where operator that return Iterator, also it filters null.
final users = [User(22, "Kasey"), User(23, "Jadn"), User(22, "Rene"), User(32, "Aden")];
final filtered = users.filter((u) => u.name == "Kasey"); // [User(22, "Kasey")] <- Type List<User>
final listWithNull = [null, User(23, "Jadn"), User(22, "Rene"), User(32, "Aden")];
final filtered = listWithNull.filter((u) => u.name == "Jadn"); // [User(23, "Jadn")]Returns a set containing all elements that are contained by both this set and the specified collection.
Set.from([1, 2, 3, 4]).intersect(Set.from([3, 4, 5, 6]) // 1,2,3,4,5,6Returns a list containing only not the elements matching the given predicate, the return type will be List,
unlike the where operator that return Iterator, also it filters null.
final users = [User(22, "Kasey"), User(23, "Jadn"), User(22, "Rene"), User(32, "Aden")];
final filtered = users.filterNot((u) => u.name == "Kasey"); // [User(23, "Jadn"), User(22, "Rene"), User(32, "Aden")] <- Type List<User>
final listWithNull = [null, User(23, "Jadn"), User(22, "Rene"), User(32, "Aden")];
final filtered = listWithNull.filterNot((u) => u.name == "Jadn"); // [User(22, "Rene"), User(32, "Aden")]Returns a list containing first [n] elements.
[1, 2, 3, 4].takeOnly(1) // [1]Returns a list containing all elements except first [n] elements.
[1, 2, 3, 4].drop(1) // [2, 3, 4]Performs the given action on each element on iterable, providing sequential index with the element.
["red","green","blue"].forEachIndexed((item, index) {
print("$item, $index");
}); // 0: red // 1: green // 2: blue``` Returns a new list with all elements sorted according to descending natural sort order.
var list = [1,2,3,4,5];
final descendingList = list.sortedDescending();
print(descendingList); // [5, 4, 3, 2, 1]Return a number of the existing elements by a specific predicate
final users = [User(33, "Miki"), User(45, "Anna"), User(19, "Amit")];
final aboveAgeTwenty = users.count((user) => user.age > 20);
print(aboveAgeTwenty); // 2Creates a Map instance in which the keys and values are computed from the iterable.
final users = [User(33, "Miki"), User(45, "Anna"), User(19, "Amit")];
users.associate((k) => k.name, (e) => e.age) // 'Miki': 33, 'Anna': 45, 'Amit': 19}Return a list concatenates the output of the current list and multiple iterables.
final listOfLists = [
[5, 6, 7],
[8, 9, 10]
];
[1, 2, 3, 4].concatWithMultipleList(listOfLists);
// [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]Returns a list containing only the elements from given collection having distinct keys.
// example 1
final users = ["Zack", "Ian", "Ronit"];
users.distinctBy((u) => u.toLowerCase().startsWith("z")); // Zack
// example 2
final users = [User(11, 'idan'), User(12, 'ronit'), User(11, 'asaf')];
final dist = users.distinctBy((u) => u.age);
dist.forEach((u) => print(u.age)); // 11, 12Zip is used to combine multiple iterables into a single list that contains the combination of them two.
final soldThisMonth = [Motorcycle(2020, 'BMW R1200GS'), Motorcycle(1967, 'Honda GoldWing')];
final soldLastMonth = [Motorcycle(2014, 'Honda Transalp'), Motorcycle(2019, 'Ducati Multistrada')];
final sales = soldThisMonth.zip(soldLastMonth).toList();
print(sales); // [
[brand: BMW R1200GS year: 2020, brand: Honda Transalp year: 2014], // first pair from this month and last
[brand: Honda GoldWing year: 1967, brand: Ducati Multistrada year: 2019] // second pair from last month
]See iterable.dart for more examples.
Are you not tired from typing MediaQuery.of(context).size... to get height or width? here’s a cool extension
context.mq // returns the MediaQuery context isLandscape // returns if Orientation is landscapecontext.sizePx // returns same as MediaQuery.of(context).sizecontext.widthPx // returns same as MediaQuery.of(context).size.widthcontext.heightPx // returns same as MediaQuery.of(context).heightfinal text = Text('hello')
.bold()
.fontSize(25)
.italic(); final someWidgetList = [
Text('hello'),
Text('world'),
].toColumnWidget(); // toRowWidget(), toStackWidget()So now we can just add round corners, shadows, align, and added gestures to our Widgets without the crazy water-fall effect. awesome!
That’s just the tip of the iceberg, expect to see very cool stuff soon.
class Home extends StatefulWidget {
@override
_HomeState createState() => _HomeState();
}
class _HomeState extends State<Home> {
@override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
child: Stack(
children: <Widget>[
Container(
height: 100,
width: 100,
) .withRoundCorners(backgroundColor: Colors.grey)
.withShadow()
.alignAtCenter()
.toCenter()
.withTooltip('just a tooltip')
.paddingOnly(left: 10)
.paddingAll(20)
.onTap(() => print('tap'))
.onLongPress(() => print('long press'))
],
),
),
);
}
}We can navigate from every widget by calling these methods
navigateTo(route: MaterialPageRoute(builder: (c) => Login()));
navigateByRouteName(Routes.home, );
final result = navigateBack();Sends an HTTP GET request with the given headers to the given URL
final json = await "https://jsonplaceholder.typicode.com/posts".httpGet();result:
[
{
"userId": 1,
"id": 1,
"title": "sunt aut facere",
"body": "quia et suscipit"
},
{
"userId": 1,
"id": 2,
"title": "qui est esse",
"body": "dolor beatae ea dolores neque"
},
]usage with then:
"https://jsonplaceholder.typicode.com/posts".httpGet().then((result) {
print(result);
}).catchError((e) => print(e));Sends an HTTP POST request with the given headers and body to the given URL which can be a [Uri] or a [String].
String json = '{"title": "Hello", "body": "body text", "userId": 1}';
final json = await "https://jsonplaceholder.typicode.com/posts".httpPost(json);for more examples (put, delete) See http.dart
Returns a sequence of integer, starting from the current number until the [end] number. [step] is optional, it will step number if given
for(final num in 1.until(10)) {
numbers.add(num);
}result
[1, 2, 3, 4, 5, 6, 7, 8, 9]with step:
for(final num in 1.until(10, step: 2)) {
numbers.add(num);
}result
[1, 3, 5, 7, 9]Returns true if this string is any of these values: “true”, “yes”, “1”, or if the string is a number and greater than 0, false if less than 1. This is also case insensitive.
'true'.asBool // true
'True'.asBool // true
'false'.asBool // false
'False'.asBool // false
'yes'.asBool // true
'YES'.asBool // true
'no'.asBool // false
'NO'.asBool // falseReturns a new string in which a specified string is inserted at a specified index position in this instance.
'test'.insert(1, 't') // 'ttest'
'123456890'.insert(6, '7') // '1234567890'
'dart cool'.insert(4, ' is') // 'dart is cool'Indicates whether a specified string is null, empty, or consists only of white-space characters.
'test'.isNullOrWhiteSpace // false
' '.isNullOrWhiteSpace, // true
null.isNullOrWhiteSpace, // true
' te st '.isNullOrWhiteSpace // falseReplace part of string after the first occurrence of given delimiter.
print("myemail@".replaceAfter("@", "gmail.com")); // myemail@gmail.com Replace part of string before the first occurrence of given delimiter.
print('@domain.com'.replaceBefore('@', "name")); // "name@domain.com"Returns true if at least one element matches the given predicate
'test'.anyChar((c) => c == 't'); // true;
'test'.anyChar((c) => c == 'd'); // false;If the string is empty perform an action.
"".ifEmpty(() => print("do any action here")); // do any action hereParses the string as an integer or returns null if it is not a number.
var number = '12345'.toDoubleOrNull(); // 12345
var notANumber = '123-45'.toDoubleOrNull(); // null Limit the string to a maximum length, taking from the end of the string.
var longString = "0123456789";
var noMoreThanThree = longString.limitFromEnd(3); // "789"Limit the string to a maximum length, taking from the start of the string.
var longString = "0123456789";
var noMoreThanThree = longString.limitFromStart(3); // "012"Return the min if this number is smaller then minimum Return the max if this number is bigger the the maximum Return this number if it’s between the range
1.inRangeOf(0, 3) // 1 number in range so will return the number
2.inRangeOf(3, 4) // 3 number is smaller then the range so will return min
5.inRangeOf(3, 4) // 4 number is bigger then the range so will return maxTooltipalgincentercontainerpaddingnavigationContextTextList<Widget>Icon
httpGethttpPosthttpPuthttpDelete
sortBytoMutableSetintersectgroupByfindfilterfilterNotisEmptyOrNullchunksziphalftakeOnlydropfirstHalfsecondHalfswapgetRandomfirstOrNullfirstOrNullWherefirstOrDefaultlastOrNulllastOrDefaultforEachIndexedsortedDescendingcontainsAllcountdistinctBysubtractconcatWithSingleListconcatWithMultipleListassociate
until
validateEmailremoveSurroundingisNullOrEmptyreplaceAfterreplaceBeforeorEmptyifEmptylastIndexprintThisequalsIgnoreCasetoDoubleOrNulltoIntOrNullanyCharremoveAllWhiteSpaceisNotBlanktoCharArrayinsertisNullOrWhiteSpaceasBool
toMillisecondstoSecondstoMinutestoHourstoDaysisTodayaddOrRemoveYearsaddOrRemoveMonthaddOrRemoveDayaddOrRemoveMinutesaddOrRemoveSecondsstartOfDaystartOfMonthstartOfYearoperator to add datesoperator to subtract datestomorrowyesterdayminmaxisLeapYearlimitFromEndlimitFromStart
inRangeOfabsoluteisEvenisOddisPositiveisNegativetenthfourththirdhalfdoubledtripledquadrupledsquaredasBool
If you have read up till here, then 🎉🎉🎉. There are couple of ways in which you can contribute to
the growing community of dart_extensions.dart.
- Propose any feature, enhancement
- Report a bug
- Fix a bug
- Participate in a discussion and help in decision making
- Write and improve some documentation. Documentation is super critical and its importance cannot be overstated!
- Send in a Pull Request 🙂
 Idan Ayalon 💻 📖 👀 |
 Xamantra 💻 📖 👀 |
Copyright 2020 Idan Ayalon
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.
https://github.com/droididan/dart_extensions
