Universal.CodeGeneration.CSharp 1.3.0

Universal.CodeGeneration.CSharp

A library for generating C# source code from various specifications, specializing in strongly-typed HTTP clients and URI builders.

Classes

HttpServiceClientGenerator

Generates complete, strongly-typed HTTP service client code from API specifications (such as OpenAPI/Swagger). It handles the generation of methods, request/response models, enums, and hierarchical resource navigation.

// Parse the OpenAPI JSON
string json = File.ReadAllText("openapi.json");
var spec = HttpServiceClientGenerator.ApiSpecification.FromOpenApi(json);

// Configure generation options
var options = new HttpServiceClientGenerator.Options
{
    BaseClass = HttpServiceClientGenerator.BaseClientType.JsonHttpServiceClient,
    GenerateModelClasses = true,
    UseHierarchicalResources = true,
    JsonSerializer = HttpServiceClientGenerator.JsonSerializerType.SystemTextJson
};

// Generate the code
var generator = new HttpServiceClientGenerator("MyApi.Client", "ApiClient", options);
string sourceCode = generator.Generate(spec);

Target framework compatibility

By default the generated client targets the latest BCL surface (using overloads that accept a CancellationToken, such as HttpContent.ReadAsStringAsync(CancellationToken)). Set TargetFramework to a target framework moniker when the generated code must compile against an older target — including .NET Standard and .NET Framework, where those overloads do not exist:

var options = new HttpServiceClientGenerator.Options
{
    BaseClass = HttpServiceClientGenerator.BaseClientType.JsonHttpServiceClient,
    // e.g. "net10.0", "netstandard2.1", "netstandard2.0", "netcoreapp3.1", "net48"
    TargetFramework = "netstandard2.0"
};

The moniker is resolved to BCL capability flags internally. Targets below .NET 5 (all netstandard*, netcoreapp*, and .NET Framework monikers) omit the newer CancellationToken overloads; net5.0 and later use them. A null, empty, or unrecognized value means "latest" and emits the newest API surface, so it automatically tracks future .NET versions without a code change.

String enums

OpenAPI type: string enums are emitted as integer-backed C# enums (C# enums cannot be string-backed). Each member keeps its original wire value via a [System.Runtime.Serialization.EnumMember] attribute, and the enum is decorated with a string-enum converter matching the configured JsonSerializer (StringEnumConverter for Newtonsoft.Json, JsonStringEnumConverter for System.Text.Json) so values round-trip correctly. Values containing spaces or other invalid identifier characters are sanitized into valid PascalCase member names — e.g. "IN PROGRESS" becomes InProgress:

[Newtonsoft.Json.JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
public enum TaskStatus
{
    [System.Runtime.Serialization.EnumMember(Value = "IN PROGRESS")]
    InProgress = 0,
    [System.Runtime.Serialization.EnumMember(Value = "DONE")]
    DONE = 1
}

UriBuilderGenerator

Generates strongly-typed UriBuilder code from route definitions. This allows for type-safe URL construction based on defined API paths, supporting both fluent and flat API styles.

// Define routes manually or parse from OpenAPI
var routes = new List<UriBuilderGenerator.ApiRoute>
{
    new UriBuilderGenerator.ApiRoute { Path = "users/{userId:int}/orders" },
    new UriBuilderGenerator.ApiRoute { Path = "products/{category}/{id}" }
};

var options = new UriBuilderGenerator.Options
{
    UseFluentGeneration = true,
    FluentOptions = new UriBuilderGenerator.FluentGenerationOptions
    {
        UseNestedNamespaces = true,
        CollapseIdMethods = true
    }
};

var generator = new UriBuilderGenerator("MyNamespace", "MyApiRoutes", options);
string sourceCode = generator.Generate(routes);

ObjectExtensions

Extensions for converting runtime objects into their C# code initialization string representation. Useful for meta-programming and generating code that initializes objects with specific states.

// Simple types
int number = 42;
string numberCode = number.ToInitializerString(); // "42"

// Collections
var list = new List<string> { "A", "B" };
string listCode = list.ToInitializerString(); 
// "new List<string>() { "A", "B" }"

// Complex objects
var data = new { Id = 1, CreatedAt = DateTime.Now };
string objectCode = data.ToInitializerString();
// Generates object initialization syntax recursively