L2WLib.Combine 2.0.3

L2WLib.Combine

L2WLib.Combine is a lightweight, production-ready .NET utility library designed to simplify backend development by providing reusable components for database operations, encryption, HTTP requests, numeric conversions, and general utilities.

It is built for fast development, secure SQL handling, lightweight architecture, and NuGet distribution.

FEATURES

DATABASE UTILITY (DBUtility)

Provides ORM-like lightweight database handling.

• Generic mapping using reflection (ExecuteGenericList<T>)
• Insert / Update / Upsert support
• Fully parameterized SQL execution (SQL injection safe)
• DataTable / DataSet helpers
• Column metadata reader
• SQL identifier validation
• Reflection caching for performance

Example: var users = DBUtility.ExecuteGenericList<User>( connectionString, "SELECT * FROM Users", CommandType.Text );

Insert: var data = new List<DBData> { new DBData("Name", "John"), new DBData("Age", 25) };

long id = DBUtility.Insert(connectionString, "Users", data);

Update: DBUtility.Update(connectionString, "Users", data, conditions);

ENCRYPTION UTILITY (AES)

AES-256 encryption/decryption using PBKDF2.

• AES encryption/decryption
• Salt-based key generation
• Base64 output
• URL-safe encoding option

⚠️ Default key is for testing only.

Example: string encrypted = Encryption.Encrypt("Hello World"); string decrypted = Encryption.Decrypt(encrypted);

HTTP UTILITY

Singleton HttpClient based HTTP helper.

• Async GET requests
• Custom headers
• Timeout handling
• Prevents socket exhaustion

Example: string response = await HttpUtility.FetchFromWebAsync("https://api.example.com");

NUMERIC TO WORD CONVERTER

Converts numbers into words with currency support.

• INR, USD, EUR support
• Decimal handling
• Negative numbers
• Fully iterative logic

Example: string words = NumericToWord.ConvertNumericToWord("12345.50", CurrencyType.INR);

Output: One Thousand Two Hundred Thirty Four and Fifty Cents Rupees Only

GENERIC UTILITY

Common backend helper utilities.

• File operations
• URL builder
• OTP generator
• Card masking
• Enum helpers
• DataTable ↔ List conversion
• IST date/time utilities
• Number formatting (Indian system)

OTP Example: string otp = GenericUtility.GetOTP(6);

File Example: bool exists = GenericUtility.IsFileExist(path);

LEGACY FORMAT EXTENSIONS

Deprecated methods for backward compatibility.

• Phone formatting
• URL formatting
• Email validation
• Date parsing

⚠️ Use modern extension methods instead.

INSTALLATION

NuGet: Install-Package L2WLib.Combine

.NET CLI: dotnet add package L2WLib.Combine

USAGE

using L2WLib.Combine;

IMPORTANT NOTES

SECURITY:

• Never use default encryption key in production
• Validate all inputs
• Use parameterized queries only

PERFORMANCE:

• Reflection caching improves performance
• Singleton HttpClient avoids socket issues
• Iterative implementations used

LIMITATIONS

• Not a full ORM like Entity Framework
• No migrations or tracking
• Lightweight utility-focused only

ARCHITECTURE

• Lightweight modular design
• Secure SQL handling
• High-performance caching
• Reusable utilities
• Minimal dependencies

FUTURE IMPROVEMENTS

• Async DB operations
• Fluent query builder
• Retry policies
• Logging system
• Encryption key provider
• Performance profiling tools

SUMMARY

L2WLib.Combine is a compact, high-performance .NET utility library that simplifies database operations, encryption, HTTP communication, and general backend development with secure and reusable components.