GTD Helper

A comprehensive Flutter utility package providing a wide range of helper functions, extensions, and UI components to streamline development.

Features

Error Handling

• GtdError: Comprehensive error handling with different error types and detailed error information.
• GtdErrorConstant: Predefined error constants for standardized error handling.

Logging

• Logger: Flexible logging system with different severity levels (VERBOSE, DEBUG, INFO, WARN, ERROR, WTF).
• Colored console output for better readability.
• Configurable log level filtering.

State Management

• AppBlocObserver: BLoC pattern observer for monitoring state changes, errors, and lifecycle events.

Caching

• AppSharedPreferences: Simplified interface for SharedPreferences with type-specific getters and setters.
• CacheHelper: Advanced caching utilities with JSON object serialization/deserialization.

Resource Loading

• GtdResourceLoader: Utilities for loading string resources from assets and packages.
• Support for loading content from specific packages with custom paths.

Utility Functions

• GlobalFunctions:
  • HMAC SHA256 encryption and verification
  • Positional utilities for UI widgets
  • JSON parsing and serialization

Result Pattern

• Result<S, E>: Implementation of the Result pattern for handling success/error responses.
• Unit: Utility class representing a void or empty response.

UI Components

• GtdButton: Customizable button with various states and appearances.
• GtdPresentViewHelper: Helper for presenting modal views.
• GtdStickyHeader: Sticky header implementation for lists.
• GtdHtmlView: HTML content rendering.
• GtdExpansionView: Customizable expansion panel.
• GtdGradientIcon: Icon with gradient color.
• GtdDashBorder: Border with customizable dash patterns.
• GtdLunarCalendar: Calendar with lunar date support and customizable colors.

Extensions

UI Extensions

• BuildContextExtension: Convenient extensions for BuildContext.
• ColorsExtension: Color manipulation (darken, lighten, avg).
• MaterialStateExtension: Utilities for MaterialState properties.
• ImageExtension: Image handling utilities.

Data Type Extensions

• StringExtension: String manipulation and validation.
• DateTimeExtension: Date formatting, comparison, and manipulation.
• NumberExtension: Number formatting and conversion.
• IterableExtension: Collection utilities.

Navigation Extensions

• GoRouterExtension: Simplified navigation with GoRouter.

List View Extensions

• LoadMoreListExtension: Infinite scrolling list implementation.
• GtdPagingScrollPhysics: Custom scroll physics for paged lists.

Network Utilities

• GtdJsonParser: Safe JSON parsing with error handling.
• HttpService: HTTP client with standardized request/response handling.

Usage

Error Handling

try {
  // Some operation
} catch (e) {
  final error = GtdError.custom("Custom error message");
  Logger.e(error.message);
}

Logging

// Set log level
Logger.setLogLevel(Logger.INFO);

// Log messages
Logger.v("Verbose message");
Logger.d("Debug message");
Logger.i("Info message");
Logger.w("Warning message");
Logger.e("Error message");

Resource Loading

// Load string from asset
final content = await GtdResourceLoader.loadContentFromResource(
  pathResource: "assets/text/terms.txt"
);

// Load string from package
final htmlContent = await GtdResourceLoader.loadFromPackage(
  packageName: "my_package",
  filePath: "assets/templates/template.html"
);

Caching

// Initialize cache
await AppSharedPreferences.init();

// Save and retrieve data
AppSharedPreferences.putString("key", "value");
final value = AppSharedPreferences.getString("key");

UI Components

Lunar Calendar

GtdLunarCalendar(
  startDate: DateTime.now(),
  mainColor: Colors.blue,
  accentColor: Colors.orange,
  lunarDateMode: GtdLunarDateMode.range,
  bottomBuilder: (context, {startDate, endDate, resetSink}) {
    // Build bottom UI
  },
)

Gradient Icon

GtdGradientIcon(
  Icons.star,
  24.0,
  LinearGradient(
    colors: [Colors.red, Colors.amber],
    begin: Alignment.topLeft,
    end: Alignment.bottomRight,
  ),
)

Extensions

// String extensions
final isValidEmail = "user@example.com".isValidEmail();
final maskedText = "1234567890".maskString(2, 2);

// DateTime extensions
final formattedDate = DateTime.now().localDate("dd/MM/yyyy");
final tomorrow = DateTime.now().addDay(1);

// Color extensions
final darkerColor = Colors.blue.darken(20);
final lighterColor = Colors.red.lighten(30);

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  gtd_helper: ^1.0.6

Requirements

• Flutter: >=3.13.0
• Dart: >=3.3.3 <4.0.0

Additional Information

For more examples, check the example project.