csharpessentials-json

name	csharpessentials-json
description	Use when configuring System.Text.Json for ASP.NET Core — JsonOptions.Default with camelCase/no-nulls/no-cycles, ConditionalStringEnumConverter for [StringEnum] enums, MultiFormatDateTimeConverter for flexible date parsing, and PolymorphicJsonConverterFactory for $type discriminator.

CSharpEssentials.Json

Pre-configured System.Text.Json options and converters for common ASP.NET Core patterns.

Installation

dotnet add package CSharpEssentials.Json

Namespace

using CSharpEssentials.Json;

---

JsonOptions.Default

Pre-configured profile: camelCase property names, ignore null values, handle circular references.

// In ASP.NET Core
builder.Services.AddControllers()
    .AddJsonOptions(o => o.JsonSerializerOptions.ApplyDefaults());

// Standalone serialization
var json = JsonSerializer.Serialize(obj, JsonOptions.Default);
var obj  = JsonSerializer.Deserialize<MyType>(json, JsonOptions.Default);

---

ConditionalStringEnumConverter

Serializes enums marked with [StringEnum] (from CSharpEssentials.Enums) as strings, and all other enums as integers.

// In setup
options.Converters.Add(new ConditionalStringEnumConverter());

// [StringEnum] enum → "Shipped" in JSON
// Regular enum     → 2 in JSON

---

MultiFormatDateTimeConverter

Deserializes DateTime / DateTimeOffset from multiple input formats (ISO 8601, custom patterns). Useful when consuming third-party APIs with inconsistent date formats.

options.Converters.Add(new MultiFormatDateTimeConverter());

---

PolymorphicJsonConverterFactory

Enables polymorphic deserialization using a $type discriminator field.

options.Converters.Add(new PolymorphicJsonConverterFactory());

// JSON: { "$type": "Circle", "radius": 5 }
// Deserializes to Circle : Shape

---

Best Practices

• Call ApplyDefaults() in one place — do not configure JsonSerializerOptions in multiple locations
• ConditionalStringEnumConverter requires enums to be decorated with [StringEnum] from CSharpEssentials.Enums
• PolymorphicJsonConverterFactory requires the discriminator field to be named $type