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C# extension for Yellicode

Generate C# code using powerful TypeScript code generation templates! This Yellicode extension lets you generate C# classes, interfaces, enumerations, structs and their members from different kinds of models, using a fully typed code writer.

License: MIT

About Yellicode

Yellicode lets you build your own code generation templates with TypeScript. It consists of a Node.js CLI and extensible APIs, making it easy for developers to create, share and re-use code generators for their favorite programming languages and frameworks.

Check out our website for more.

Using the C# package


In order to run a code generation template, you must have the CLI installed (@yellicode/cli) globally and have a valid codegenconfig.json file in your working directory. Please refer to the installation instructions and the quick start for more.


Open a terminal/command prompt in your working directory and install this package as a dev dependency:

npm install @yellicode/csharp --save-dev

Using the CSharpWriter

The main class for generating C# code is the CSharpWriter. The CSharpWriter can work with 2 different model kinds as input:

Most CSharpWriter functions have 2 overloads which can be used for each different kind of input. For example, the writeClassBlock function has the following overloads:

  1. public writeClassBlock(definition: ClassDefinition, contents: () => void): void;
  2. public writeClassBlock(cls: elements.Class, contents: () => void, options?: opts.ClassOptions): void;

The first overload accepts a ClassDefinition, which has the following structure (comments left out for brevity):

export interface ClassDefinition extends TypeDefinition {
    isStatic?: boolean;
    isAbstract?: boolean;
    isSealed?: boolean;
    implements?: string[];
    inherits?: string[];
    properties?: PropertyDefinition[];
    methods?: MethodDefinition[];

When using this overload, you should build the definition in your code generation template. You can do this manually, but typically you would configure a JSON file as model (see the Yellicode quick start for a how-to) and transform that JSON structure to a C# definition.

The second overload accepts a class instance from a Yellicode model and accepts an optional ClassOptions object to control code generation (internally, the Yellicode class is transformed to a ClassDefinition).


Note: a ZIP archive with working examples is also available for download here.

Example using a C# code definition

This sample creates a simple C# definition of a Task class, which is then provided to the CSharpWriter. You would typically create this definition from another structure (your own JSON model, using the 'model' parameter).

import { TextWriter } from '@yellicode/core';
import { Generator } from '@yellicode/templating';
import { CSharpWriter, ClassDefinition, NamespaceDefinition } from '@yellicode/csharp';

Generator.generateFromModel({ outputFile: './custom-sample.cs' }, (output: TextWriter, model: any) => {

    // Build a C# definition in code. You could alternatively configure any JSON file as model
    // and transform that data - available in the 'model' parameter - to a C# definition.
    const namespaceDefinition: NamespaceDefinition = { name: 'SampleNamespace' };

    const classDefinition: ClassDefinition = {
        name: 'Task',
        accessModifier: 'public',
        xmlDocSummary: ['Represents an activity to be done.']
    }; = [
        { name: 'TaskDescription', typeName: 'string', accessModifier: 'public', xmlDocSummary: ['Gets or sets a description of the task.'] },
        { name: 'IsFinished', typeName: 'bool', accessModifier: 'public', xmlDocSummary: ['Indicates if the task is finished.'] }

    // Write the namespace, the classes and its properties
    const csharp = new CSharpWriter(output);
    csharp.writeNamespaceBlock(namespaceDefinition, () => {
        csharp.writeClassBlock(classDefinition, () => {
   => {

The generated C# code will look as follows:

namespace SampleNamespace
	/// <summary>
	/// Represents an activity to be done.
	/// </summary>
	public class Task
		/// <summary>
		/// Gets or sets a description of the task.
		/// </summary>
		public string TaskDescription { get;set; }

		/// <summary>
		/// Indicates if the task is finished.
		/// </summary>
		public bool IsFinished { get;set; }

Example using a Yellicode model

For navigating a Yellicode model in template code, you should also have the @yellicode/elements package installed in your working directory:

npm install @yellicode/elements --save-dev

This template generates a C# code file with all classes in the model and, for each class, writes an auto-property for each class attribute.

import { TextWriter } from '@yellicode/core';
import { Generator } from '@yellicode/templating';
import { CSharpWriter } from '@yellicode/csharp';
import * as elements from '@yellicode/elements';

Generator.generateFromModel({ outputFile: './model-based-sample.cs' }, (output: TextWriter, model: elements.Model) => {
    const csharp = new CSharpWriter(output);
    model.getAllClasses().forEach(cls => {
        csharp.writeClassBlock(cls, () => {
            cls.ownedAttributes.forEach(att => {
        }, { isPartial: true }); // marking the class 'partial'

API Documentation

For all CSharpWriter functions and options, check out the API documentation.