Examples Overview

This section provides various usage examples for Apq.Cfg.

Default Levels

Each configuration source has a default level. If not specified, the default level is used:

Source Type	Default Level
Json, Ini, Xml, Yaml, Toml	0
Redis, Database	100
Consul, Etcd, Nacos, Apollo, Zookeeper	200
Vault	300
.env, EnvironmentVariables	400

Example Categories

Basic Examples

• Basic Examples - Basic configuration reading and type conversion
• Multi-Source - Combining multiple configuration sources

Integration Examples

• DI Integration - ASP.NET Core integration
• Dynamic Reload - Configuration hot reload

Advanced Examples

• Complex Scenarios - Enterprise application configuration
• Encryption & Masking - Configuration encryption and masking

Quick Examples

Simplest Usage

using Apq.Cfg;

var cfg = new CfgBuilder()
    .AddJsonFile("config.json")  // Uses default level 0
    .Build();

var appName = cfg["App:Name"];
Console.WriteLine($"App Name: {appName}");

Multi-Source

var cfg = new CfgBuilder()
    .AddJsonFile("config.json")                        // Uses default level 0
    .AddYamlFile("config.yaml", level: 10, optional: true)
    .AddEnvironmentVariables(prefix: "APP_")       // Uses default level 400
    .Build();

Strongly-Typed Binding

public class DatabaseConfig
{
    public string Host { get; set; } = "";
    public int Port { get; set; } = 5432;
}

var dbSection = cfg.GetSection("Database");
var dbConfig = new DatabaseConfig
{
    Host = dbSection["Host"] ?? "localhost",
    Port = dbSection.GetValue<int>("Port")
};
Console.WriteLine($"Database: {dbConfig.Host}:{dbConfig.Port}");

Dependency Injection

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddApqCfg(cfg => cfg
    .AddJsonFile("config.json")                        // Uses default level 0
    .AddEnvironmentVariables(prefix: "APP_"));    // Uses default level 400

builder.Services.ConfigureApqCfg<DatabaseConfig>("Database");

Dynamic Reload

var cfg = new CfgBuilder()
    .AddJsonFile("config.json", reloadOnChange: true)  // Uses default level 0
    .Build();

cfg.ConfigChanges.Subscribe(e =>
{
    Console.WriteLine("Configuration updated!");
    foreach (var (key, change) in e.Changes)
    {
        Console.WriteLine($"  [{change.Type}] {key}");
    }
});

Encryption & Masking

using Apq.Cfg.Crypto;

var cfg = new CfgBuilder()
    .AddJsonFile("config.json")            // Uses default level 0
    .AddAesGcmEncryptionFromEnv()      // Read key from environment variable
    .AddSensitiveMasking()             // Add masking support
    .Build();

// Encrypted value in config: { "Database": { "Password": "{ENC}base64..." } }
// Auto-decrypt on read
var password = cfg["Database:Password"];

// Use masked value for logging
Console.WriteLine($"Password: {cfg.GetMasked("Database:Password")}");
// Output: Password: myS***ord

Writable Configuration

var cfg = new CfgBuilder()
    .AddJsonFile("config.json", writeable: true, isPrimaryWriter: true)  // Uses default level 0
    .Build();

// Modify configuration
cfg.SetValue("App:Name", "NewName");
cfg.SetValue("Database:Port", "5433");

// Save to file
await cfg.SaveAsync();

Run Sample Project

The repository includes complete sample code:

cd Samples/Apq.Cfg.Samples
dotnet run

Next Steps

Choose an example to learn more:

• Basic Examples
• Multi-Source
• DI Integration