Marcin Jahn | Dev Notebook
  • Home
  • Programming
  • Technologies
  • Projects
  • About
  • Home
  • Programming
  • Technologies
  • Projects
  • About
  • An icon of the Core section Core
    • Programs Execution
    • Stack and Heap
    • Asynchronous Programming
      • Overview
      • Event Queues
      • Fibers
      • Stackless Coroutines
  • An icon of the .NET section .NET
    • HTTPClient
    • Async
      • How Async Works
      • TAP Tips
    • Equality
    • Comparisons
    • Enumerables
    • Unit Tests
    • Generic Host
    • Logging
    • Configuration
    • Records
    • Nullability
    • Garbage Collector
    • IL and Allocations
    • gRPC
    • Source Generators
    • Platform Invoke
    • ASP.NET Core
      • Overview
      • Middleware
      • Razor Pages
      • Routing in Razor Pages
      • Web APIs
      • Filters
      • Identity
      • Validation
      • Tips
    • Entity Framework Core
      • Overview
      • Testing
      • Tips
  • An icon of the Angular section Angular
    • Overview
    • Components
    • Directives
    • Services and DI
    • Routing
    • Observables (RxJS)
    • Forms
    • Pipes
    • HTTP
    • Modules
    • NgRx
    • Angular Universal
    • Tips
    • Standalone Components
  • An icon of the JavaScript section JavaScript
    • OOP
    • JavaScript - The Weird Parts
    • JS Functions
    • ES Modules
    • Node.js
    • Axios Tips
    • TypeScript
      • TypeScript Environment Setup
      • TypeScript Tips
    • React
      • React Routing
      • MobX
    • Advanced Vue.js Features
  • An icon of the Rust section Rust
    • Overview
    • Cargo
    • Basics
    • Ownership
    • Structures
    • Enums
    • Organization
    • Collections
    • Error Handling
    • Generics
    • Traits
    • Lifetimes
    • Closures
    • Raw Pointers
    • Smart Pointers
    • Concurrency
    • Testing
    • Tips
  • An icon of the C/C++ section C/C++
    • Compilation
    • Structures
    • OOP in C
    • Pointers
    • Strings
    • Dynamic Memory
    • argc and argv Visualization
  • An icon of the GTK section GTK
    • Overview
    • GObject
    • GJS
  • An icon of the CSS section CSS
    • Responsive Design
    • CSS Tips
    • CSS Pixel
  • An icon of the Unity section Unity
    • Unity
  • An icon of the Functional Programming section Functional Programming
    • Fundamentals of Functional Programming
    • .NET Functional Features
    • Signatures
    • Function Composition
    • Error Handling
    • Partial Application
    • Modularity
    • Category Theory
      • Overview
      • Monoid
      • Other Magmas
      • Functors
  • An icon of the Algorithms section Algorithms
    • Big O Notation
    • Array
    • Linked List
    • Queue
    • Hash Table and Set
    • Tree
    • Sorting
    • Searching
  • An icon of the Architecture section Architecture
    • What is architecture?
    • Domain-Driven Design
    • ASP.NET Core Projects
  • An icon of the Core section Core
    • Programs Execution
    • Stack and Heap
    • Asynchronous Programming
      • Overview
      • Event Queues
      • Fibers
      • Stackless Coroutines
  • An icon of the .NET section .NET
    • HTTPClient
    • Async
      • How Async Works
      • TAP Tips
    • Equality
    • Comparisons
    • Enumerables
    • Unit Tests
    • Generic Host
    • Logging
    • Configuration
    • Records
    • Nullability
    • Garbage Collector
    • IL and Allocations
    • gRPC
    • Source Generators
    • Platform Invoke
    • ASP.NET Core
      • Overview
      • Middleware
      • Razor Pages
      • Routing in Razor Pages
      • Web APIs
      • Filters
      • Identity
      • Validation
      • Tips
    • Entity Framework Core
      • Overview
      • Testing
      • Tips
  • An icon of the Angular section Angular
    • Overview
    • Components
    • Directives
    • Services and DI
    • Routing
    • Observables (RxJS)
    • Forms
    • Pipes
    • HTTP
    • Modules
    • NgRx
    • Angular Universal
    • Tips
    • Standalone Components
  • An icon of the JavaScript section JavaScript
    • OOP
    • JavaScript - The Weird Parts
    • JS Functions
    • ES Modules
    • Node.js
    • Axios Tips
    • TypeScript
      • TypeScript Environment Setup
      • TypeScript Tips
    • React
      • React Routing
      • MobX
    • Advanced Vue.js Features
  • An icon of the Rust section Rust
    • Overview
    • Cargo
    • Basics
    • Ownership
    • Structures
    • Enums
    • Organization
    • Collections
    • Error Handling
    • Generics
    • Traits
    • Lifetimes
    • Closures
    • Raw Pointers
    • Smart Pointers
    • Concurrency
    • Testing
    • Tips
  • An icon of the C/C++ section C/C++
    • Compilation
    • Structures
    • OOP in C
    • Pointers
    • Strings
    • Dynamic Memory
    • argc and argv Visualization
  • An icon of the GTK section GTK
    • Overview
    • GObject
    • GJS
  • An icon of the CSS section CSS
    • Responsive Design
    • CSS Tips
    • CSS Pixel
  • An icon of the Unity section Unity
    • Unity
  • An icon of the Functional Programming section Functional Programming
    • Fundamentals of Functional Programming
    • .NET Functional Features
    • Signatures
    • Function Composition
    • Error Handling
    • Partial Application
    • Modularity
    • Category Theory
      • Overview
      • Monoid
      • Other Magmas
      • Functors
  • An icon of the Algorithms section Algorithms
    • Big O Notation
    • Array
    • Linked List
    • Queue
    • Hash Table and Set
    • Tree
    • Sorting
    • Searching
  • An icon of the Architecture section Architecture
    • What is architecture?
    • Domain-Driven Design
    • ASP.NET Core Projects

.NET Configuration

The configuration system depends on configuration providers - the sources of configuration data.

Options

services.Configure<MyOptions>(Configuration.GetSection("MyOptions"));

The IOptions<T> instance is registered as a singleton.

Reloading

To support configuration providers that can be reloaded during runtime, we can inject IOptionsSnapshot<T> instead of IOptions<T>.

The class/record for our options needs to have properties that:

  • are public
  • have getters
  • have setters (or non-null value if complex type)
  • are not indexers

IEnumerable

An IEnumerable<T> property that is initialized cannot be bound to. That’s becasue IEnumerable<T> does not have the Add method.

Lambda

We are able to customize Options in runtime:

services.Configure<MyOptions>(Configuration.GetSection("MyOptions"));
services.Configure<MyOptions>(options =>
{
options.Mode = Modes.Mode1;
});

The configuration system executes both operations. First, the IConfiguration is read and then Mode property is overwritten.

Without Options

Nuget packages:

  • Microsoft.Extensions.Configuration;
  • Microsoft.Extensions.Configuration.Files.Json
  • Microsoft.Extensions.Configuration.Binder

Building

private static AppConfiguration GetConfiguration()
{
var rawConfig = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("appsettings.json")
.Build();
return ConfigurationBinder.Get<AppConfiguration>(rawConfig);
}

References

  • Options pattern guidance for .NET library authors (MSDN)
←  Logging
Records  →
© 2023 Marcin Jahn | Dev Notebook | All Rights Reserved. | Built with Astro.