sz_core 1.0.4

SZ Core Package

SZ Core

A lightweight Flutter package that provides reusable widgets, responsive sizing, utility methods, dialogs, navigation helpers, and a simple API caller to speed up Flutter application development.

Features

• ✅ Responsive UI scaling (.w, .h, .r, .sp)
• ✅ Base Activity & Fragment architecture
• ✅ Built-in API caller (GET & POST)
• ✅ Toasts, dialogs & pickers
• ✅ Navigation helper
• ✅ Phone, Website & WhatsApp launcher
• ✅ Keyboard helper
• ✅ Date & Time formatting
• ✅ Random Dark Color generator
• ✅ Hex Color extension

---

Included Classes

• SZCore
• SZActivity
• SZFragment
• SZApiCaller
• SZApiSetting
• SZShow
• SZText
• SZButton
• SZIconButton
• SZTextField

---

Installation

Add the package to your pubspec.yaml.

dependencies:
  sz_core: ^1.0.0

Then run

flutter pub get

---

Import

import 'package:sz_core/sz_core.dart';

---

Initialization

Initialize SZCore before runApp().

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await SZCore.init();

  runApp(const MyApp());
}

With Base URL

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await SZCore.init(
    baseURL: "https://example.com/api/",
  );

  runApp(const MyApp());
}

Custom API Settings

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  SZApiSetting.init(
    "https://example.com/api/",
    keyStatus: "status",
    keyMessage: "message",
    keyData: "data",
    keyInternet: "internet", 
    defaultHeader: {
      "Authorization": "Bearer TOKEN"
    }
  );

  await SZCore.init();

  runApp(const MyApp());
}

You can update custom setting directly from anywhere like

SZApiSetting.defaultHeader = {
   "Authorization": "Bearer UPDATED TOKEN"
};

---

Responsive Size

SZCore.init() automatically calculates the screen scale.

Use the extensions anywhere.

Container(
  width: 120.w,
  height: 60.h,
  padding: EdgeInsets.all(12.r),
  child: SZText(
    "Hello",
    fontSize: 16.sp,
  ),
)

Extension	Description
.w	Width scaling
.h	Height scaling
.r	Radius scaling
.sp	Responsive font size

---

SZActivity

Replace State with SZActivity.

Replace build() with buildContent().

class HomeActivity extends StatefulWidget {
  const HomeActivity({super.key});

  @override
  State<HomeActivity> createState() => _HomeActivityState();
}

class _HomeActivityState extends SZActivity<HomeActivity> {

  @override
  Widget buildContent(BuildContext context) {
    return const SizedBox();
  }
}

Available Methods

showDialog("Loading...");
hideDialog();

open(const SecondActivity());

onResume();

onPaused();

---

SZFragment

Replace State with SZFragment.

Replace build() with buildContent().

class HomeFragment extends StatefulWidget {
  const HomeFragment({super.key});

  @override
  State<HomeFragment> createState() => _HomeFragmentState();
}

class _HomeFragmentState extends SZFragment<HomeFragment> {

  @override
  Widget buildContent(BuildContext context) {
    return const SizedBox();
  }
}

Available Methods

showDialog("Loading...");
hideDialog();

open(const SecondActivity());

onResume();

onPaused();

---

SZCore

Open Activity

await SZCore.open(
  context,
  const HomeActivity(),
);

---

Hide Keyboard

SZCore.hideKeyboard(context);

---

Screen Size

final size = await SZCore.getScreenSize();

print(size.width);
print(size.height);

---

Date Formatting

Server format

SZCore.formattedDate(DateTime.now());

Output

2026-07-07

Display format

SZCore.formattedDate(
  DateTime.now(),
  server: false,
);

Output

7 Jul 2026

---

Time Formatting

Server

SZCore.formattedTime(DateTime.now());

Output

14:30

Display

SZCore.formattedTime(
  DateTime.now(),
  server: false,
);

Output

2:30 PM

---

Random Dark Color

Color color = SZCore.getRandomDarkColor();

---

Debug Log

SZCore.printLog("Hello");

Prints only in Debug mode.

---

Open Phone Dialer

SZCore.openCall("9876543210");

---

Open Website

SZCore.openWebsite(
  "https://flutter.dev",
);

---

Open WhatsApp

SZCore.openWhatsApp(
  "919876543210",
  message: "Hello",
);

---

Hex Color Extension

Color color = "#2196F3".toColor();

---

SZShow

Toast

SZShow.toast("Saved Successfully");

Custom

SZShow.toast(
  "Error",
  bg: Colors.red,
  color: Colors.white,
  size: 14,
);

---

Dialog

SZShow.dialog(
  context,
  "Success",
  "Data Saved Successfully",
);

Two Buttons

SZShow.dialog(
  context,
  "Delete",
  "Delete this record?",
  btn1: "Yes",
  btn2: "No",
  b1Click: () {

  },
  b2Click: () {

  },
);

Custom Widget

SZShow.dialog(
  context,
  "",
  "",
  buildContent: (setState) {
    return const Text("Custom Widget");
  },
);

---

Date Picker

SPair date = await SZShow.dateSelect(
  context,
  null,
);

---

Time Picker

SPair time = await SZShow.timeSelect(
  context,
  null,
);

---

Year Picker

int year = await SZShow.yearSelect(
  context,
  2025,
);

---

SZApiCaller

Supports both GET and POST requests.

GET Request

SZApiCaller(
  context,
  this,
  1,
  null,
  "Loading...",
  "users",
).then((response, key) {

});

---

POST Request

SZApiCaller(
  context,
  this,
  2,
  jsonEncode(data),
  "Please wait...",
  "login",
).then((response, key) {

});

PUT,PATCH,DELETE Request

You can use below enum

enum SZMethod { get, post, delete, put, patch }

SZApiCaller(
  context,
  this,
  2,
  jsonEncode(data),
  "Please wait...",
  "login",
  method = SZMethod.put
).then((response, key) {

});

---

Custom Header

SZApiCaller(
  context,
  this,
  1,
  null,
  null,
  "users",
  customHeader: {
    "Authorization": "Bearer TOKEN"
  },
).then((response, key) {

});

---

Logout Callback

SZCore.logoutCallback = () {
  // Navigate to Login Screen
};

If the API response contains "session expire", the callback is automatically invoked.

---

Requirements

• Flutter SDK >= 3.0.0

---

Contributing

Contributions, issues, and feature requests are welcome.

---

License

This project is licensed under the MIT License. See the LICENSE file for details.