Utility

DateTime extension

Convert DateTime object to formatted String. Usage

import 'core/utils/datetime_extension.dart'

final dateTime = DateTime.now();
final formattedDate = dateTime.dateFormat('dd-MM-yyyy');
print(formattedDate); // 30-09-2022

List of common Datetime pattern. For example if DateTime.now() = 30 Sep 2022 15:19:20

Pattern	Outputs
yyyy	2022
MM	09
dd	30
HH	15
mm	19
ss	20
MMM	Sep
EEE	Fri
dd-MM-yyyy	30-09-2022
dd MMM yyyy	30 Sep 2022
EEE, dd MMM yyyy	Fri, 30 Sep 2022
You can browse the full pattern list from here

Int to IDR formatter

Usage :

int price = 100000;
print(price.toIDR); // Rp. 100 000,-

Json Custom Parser

JsonSerializable is not able to convert data when the type is not match. Like example when we try to parse this data

{"price":"10000"}

and we have data model like this

import 'package:json_annotation/json_annotation.dart';
part '../../../gen/core/data/model/product.g.dart';

@JsonSerializable
class Product {
    
    @JsonKey(name: 'price')
    final int price;

    const User({required this.price});

    factory Product.fromJson(Map<String, dynamic> json) => _$ProductFromJson(json);
}

It will crash on runtime because the json data of price is string, not int. So we will use custom parser that we implements from JsonConverter class and add that custom parser to Product class

Use this class as annotation in your models. Example :

import 'package:json_annotation/json_annotation.dart';
import 'package:package_name/core/utils/json_custom_parser.dart'; // 1. Add this import
part '../../../gen/core/data/model/product.g.dart';

@JsonSerializable
@JsonStringToInt // 2. Add this custom annotation
class Product {
    
    @JsonKey(name: 'price')
    final int price;

    const User({required this.price});

    factory Product.fromJson(Map<String, dynamic> json) => _$ProductFromJson(json);
}

Here is list of available custom parser :

- JsonStringToInt

Parse potential nullable string to int, without this it will crash whenever we try to parse data like this {"price":"10000"}. When failed to parse data then it will return 0

- JsonStringToIntNullable

Same as JsonStringToInt but it will return null instead of 0 when parse failed

- JsonStringToDouble

Parse potential nullable string to double. Return 0 if data is null

- JsonStringToDoubleNullable

Same as JsonStringToDoubleNullable but it will return null instead of 0 when parse failed

- JsonIntToBool

Parse 1 as true and 0 as false

Media Service

Use this class to pick image from camera or gallery. Example usage :

// get MediaService instance from service locator
final mediaService = getIt<MediaService>();

AppButton(
    onClick: ()  {
        // method getImage return Future<File?>
        // AppImageSource.gallery -> open gallery to pick image
        // AppImageSource.camera -> open camera to pick image
        mediaService.getImage(context, AppImageSource.gallery)
                    .then((file) => print(file));
    }
)

Bloc Transformer

This starter is already include bloc_concurrency library that consist of 4 default transformer :

• concurrent : process event concurrently

• sequential : process event sequentially

• droppable : ignore any event added while an event is processing

• restartable : process only latest event and cancel previous event handler

Bonus :

• debounceSequential : delay process of any event. Usefull to delay user input like search feature

Example usage :

import 'package:name/core/utils/bloc_transformer.dart';

class SearchProduct extends Bloc<SearchEvent, SearchState> {
    SearchProduct() : super(SearchInitial()) {

        on<KeywordEnteredEvent>((event, emit) {
            debugPrint(event.searchKeyword);
        }, transformer: debounceSequential(const Duration(seconds: 1))); // delay user input for 1 sec
    
    }
}

Let Callback

Execute callback when value is not null. Usefull checking null value. Example usage :

import 'package:name/core/utils/let.dart';

void main(){
    String name?
    name?.let((it) => print(it)); // won't execute

    name = 'flutter';

    name?.let((it) => print(it)); // flutter
}

Password Strength

Find the password strength of given String.

• PasswordStrength.weak : <8 character

• PasswordStrength.medium : >= 8 character with number

• PasswordStrength.strong : >= 8 character with number and uppercase letter

• PasswordStrength.veryStrong : >= 8 character with number, uppercase, and special symbol

Example usage :

import 'package:name/core/utils/password_helper.dart';

String? newPassword = 'P@ssw0rd';

print(newPassword.passwordStrength); // PasswordStrength.veryStrong

Self Sign Cert

Bypass network error when there is invalid https certificate. Use this for debugging purpose only because it can risk our user to MITM attack, for example when we need to debug or intercept http request with third party tools like burpsuite or postman. Example usage :

import 'package:flutter/foundation.dart';
import 'core/utils/self_sign_cert.dart';

void main() {
    if (kDebugMode) {
        HttpOverrides.global = SelfSignCert();
    }
}

Email Validator

Check if email is valid. Example usage

import 'package:name/core/utils/string_extension.dart';

String? email = 'flutter.dev';
print(email.isValidEmail); // false

email = '[e-mail]';
print(email.isValidEmail); // true

Remove Html Tags

Remove all html tags. Example usage

import 'package:name/core/utils/string_extension.dart';

String? htmlString = '<p>Hello Mom</p>';
print(htmlString.removeHtmlTags); // Hello Mom

Asset Icon to Google Maps Marker Converter

Use this extension to convert existing marker icon assets (ex: assets/images/marker.png) to Uint8List. Usefull to convert asset icon to marker bitmap.

import 'package:name/core/utils/string_extension.dart';

void convert() async {
    String? icon = 'assets/images/marker.png'; // path to icon
    Uint8List markerBytes = await icon.uint8List; // conversion result, use this as marker icon for google map
}

Notification Service

Usage :

1. Initialize service.

void main() async {
    await NotificationService.setup();
}

1. Show notification

AppButton(
    onClick: () => NotificationService.showNotification(
        title: 'Notification Title',
        body: 'Notification Body',
    )
)

To replace default notification icon

• android : app/src/main/res/mipmap*/ic_launcher.png

• ios : coming soon