XUniqueList - A Dart/Flutter Package for Managing Unique Lists

XUniqueList is a utility package that ensures uniqueness in your lists based on a custom condition you define. It's perfect for managing collections of objects that must adhere to specific uniqueness rules.

Platform Support

Android	IOS	Web	MacOS	Linux	Windows
✅	✅	✅	✅	✅	✅

📜 Table of Contents

• ✨ Features
• 🚀 Getting Started
• 📝 Usage
• 🧩 Methods
• 🔜 Next Steps
• 📄 License

✨ Features

• 🆕 Unique List Management: Add, insert, or remove items while ensuring no duplicates based on a custom condition.
• 🚀 Fast Operations: Optimized operations for adding, removing, and filtering items.
• 🔄 Replace & Modify: Replace items by condition or unique value.
• 🔍 Check for Existence: Quickly check if an item exists based on the uniqueness condition.
• 📦 Unmodifiable and Modifiable Access: Retrieve unmodifiable and modifiable versions of the list as needed.

🚀 Getting Started

To start using XUniqueList, you need to add the following dependency to your pubspec.yaml file:

dependencies:
  x_unique_list: ^1.0.7

flutter pub get

dart pub get

📝 Usage

Here’s an example of using XUniqueList with a custom uniqueCondition based on the id field of a User class:

import 'package:x_unique_list/x_unique_list.dart';

class User {
  final int id;
  final String name;

  User(this.id, this.name);

  @override
  String toString() => 'User(id: $id, name: $name)';

  // Override equality operator to compare both id and name
  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
          (other is User && id == other.id && name == other.name);

  @override
  int get hashCode => Object.hash(id, name);
}

void main() {
  // Define a unique condition (in this case, users are unique by their ID)
  final uniqueUsers = XUniqueList<User>((user) => user.id);

  // Add users
  uniqueUsers.add(User(1, 'Ahmad'));
  uniqueUsers.add(User(2, 'Nour'));

  // Attempt to add a duplicate user (will not be added)
  uniqueUsers.add(User(1, 'Ahmad')); // This won't be added as ID 1 already exists

  // Retrieve unmodifiable list of users
  print(uniqueUsers.items); // [User(id: 1, name: Ahmad), User(id: 2, name: Nour)]

  // Remove a user - ⚠️ NOTE: This may not work as expected
  // ⚠️ Won't work unless you override `==` and `hashCode` for User
  uniqueUsers.remove(User(2, 'Nour'));

  // Explanation:
  // The `remove` method uses the `==` operator to check if the items match.
  // By default, Dart compares objects by their memory reference, not by the fields inside the object.
  // To make this work, you need to either manually override the `==` operator and `hashCode`
  // for your model (as shown above), or use third-party libraries like `equatable`, `freezed`, etc.

  // As an alternative, you can use `removeOneWhere` to remove an item by a condition
  uniqueUsers.removeOneWhere((user) => user.id == 2); // Works even without `==` override

  // Check if list contains a user
  // ⚠️ Important Note on `contains` Method
  // 
  // The `contains` method in `XUniqueList` relies on the `uniqueCondition` you define.
  // In the example above, the `uniqueCondition` is based on the `id` field of the `User` class.
  //
  // This means that when you check for the existence of an item using `contains`,
  // it only considers the value provided by the `uniqueCondition` function, not the entire object.
  //
  // For instance:
  bool exists = uniqueUsers.contains(User(1, 'Ahmad'));
  print(exists); // true
  // Even though the name 'Ahmad' is different from any existing user, the contains method returns true
  // because the id field (which is the unique condition) matches the ID of an existing user (ID = 1).

  // To check for existence or remove items based on different criteria (such as the name),
  // you can use the removeOneWhere method, which allows for more complex condition-based logic.
}

🧩 Methods

The XUniqueList class provides various methods for managing unique lists. Here is a comprehensive overview of all the methods available:

List<T> get unmodifiableItems;

• Description: Retrieve items as an unmodifiable list.

List<T> get items;

• Description: Retrieve items as a modifiable list.

T operator [](int index);

• Description: The object at the given [index] in the list.

bool add(T item);

• Description: Add a single item.

int addAll(List<T> newItems);

• Description: Add multiple items.
• Returns: The number of items that were successfully added.

bool insert(int index, T item);

• Description: Insert an item at the specified index.
• Returns: True if the item was inserted successfully, false if the item already exists.

int insertAll(int index, Iterable<T> newItems);

• Description: Insert multiple items at the specified index.
• Returns: The number of items that were successfully inserted.

bool remove(T item);

• Description: Remove a single item.

bool removeOneWhere(bool Function(T item) test);

• Description: Remove a single item based on a condition.
• Returns: True if an item was removed, false otherwise.

void removeWhere(bool Function(T item) test);

• Description: Remove items based on a condition.

bool replaceOne(T newItem);

• Description: Replace an existing item with a new item based on unique condition.

bool replaceOneWhere(T newItem, bool Function(T item) test);

• Description: Replace item that matches a condition with a new item.

void sort([int Function(T a, T b)? compare]);

• Description: Sort the list in place using the provided [compare] function. If no [compare] function is provided, the list is sorted in natural order.

List<T> where(bool Function(T item) test);

• Description: Method to filter items based on a condition.

T? firstWhere(bool Function(T item) test);

• Description: Retrieve a single item based on a condition.

int indexWhere(bool Function(T item) test, [int start = 0]);

• Description: Returns the index of the first item that satisfies the provided [test] function.
• Returns: -1 if no such item is found.

int indexOf(T item, [int start = 0]);

• Description: Returns the index of the first occurrence of [item] in the list.
• Returns: -1 if the item is not found.

bool contains(T item);

• Description: Check if the list contains an item based on the unique condition.

int get length;

• Description: Get the length of the list.

bool get isEmpty;

• Description: Check if the list is empty.

bool get isNotEmpty;

• Description: Check if the list is not empty.

void clear();

• Description: Clear all items from the list and set.

🔜 Next Steps

Adding Helper Methods

In future updates, we plan to introduce additional helper methods to further enhance the functionality of the XUniqueList class.

📄 License

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