CodegenCS is a Toolkit for doing Code Generation using plain C#.

Before anything else, don't forget to read the Main Project Page to learn the basics (basic idea, basic features, and major components).

This page is only about CodegenCS Visual Studio Extension:

• If you are writing a template (code generator) and want to learn more about CodegenCS features (and internals) then check out the CodegenCS Main Project documentation.
• If you want to compile and run templates or reverse-engineer a database schema check out the Command-line Tool dotnet-codegencs documentation
• If you want to browse the sample templates (POCO Generators, DAL generators, etc) check out https://github.com/CodegenCS/Templates/
• If you just want to download the Visual Studio Extension this is the right place.

Visual Studio Extension

CodegenCS has two editions of the Visual Studio Extension.
If you have Visual Studio 2022+ you should use the VS2022 Edition, which is the latest. (if it doesn't work for any reason you can also try the Compatibility Edition).
If you have Visual Studio 2019 you should use the Compatibility Edition, which allows templates to be compiled and executed using an isolated AppDomain (so that latest Roslyn libraries don't conflict with older VS2019 libraries).

Edition	Description	Source	Visual Studio Marketplace
VS2022	Works with Visual Studio 2022+	Sources	Download here
Compatibility Edition	Works with Visual Studio 2019+ (compiles and executes templates using an isolated AppDomain)	Sources	Download here

Quickstart

• Install it from Visual Studio (Tools - Extensions - search for "CodegenCS") or download it here
• Create a new file with csx extension. See some sample templates below
• To run your template right-click the template (in Solution Explorer) and select "Run Template"
• To make the template run automatically after each save select the template (in Solution Explorer) and in Properties set the "Custom Tool" to be "CodegenCS"

Sample Template:

// Single-file output, where `Main()` returns directly the main template
// "Text" approach
public class MyTemplate
{
    FormattableString Main()
    {
        var model = new { Tables = new string[] { "Users", "Products" } };
        return $$"""
            namespace MyNamespace
            {
                {{model.Tables.ToList().Select(t => GenerateTable(t))}}
            }
            """;
    }
    FormattableString GenerateTable(string tableName)
    {
        return $$"""
            public class {{tableName}}
            {
                // my properties...
            }
            """;
    }
}

Sample Template:

// Multiple-files output, with programmatic approach
public class MyTemplate
{
    void Main(ICodegenContext context)
    {
        var model = new { Tables = new string[] { "Users", "Products" } };
        foreach (var table in model.Tables)
            context[table + ".cs"]
            .WriteLine("//"+ table)
            .WriteLine(GenerateTable(table));
    }
    FormattableString GenerateTable(string tableName)
    {
        return $$"""
            namespace MyNamespace
            {
                public class {{tableName}}
                {
                    // my properties...
                }
            }
            """;
    }
}

Sample Template:

// Reading model from JSON file
public class MyTemplate
{
    void Main(ICodegenContext context, IModelFactory factory)
    {
        var model = factory.LoadModelFromFile<DatabaseSchema>("AdventureWorks.json");
        foreach (var table in model.Tables)
            context[table.TableName + ".cs"].WriteLine(GenerateTable(table));
    }
    FormattableString GenerateTable(Table table)
    {
        return $$"""
            namespace MyNamespace
            {
                public class {{table.TableName}}
                {
                    // my properties...
                }
            }
            """;
    }
}

Sample Template:

// Reading model from JSON file with explicit writing to files
public class MyTemplate
{
    void Main(ICodegenContext context, IModelFactory factory)
    {
        var model = factory.LoadModelFromFile<DatabaseSchema>("AdventureWorks.json");
        foreach (var table in model.Tables)
            GenerateTable(context[table.TableName + ".cs"], table);
    }
    void GenerateTable(ICodegenTextWriter writer, Table table)
    {
        writer.WriteLine($$"""
            namespace MyNamespace
            {
                public class {{table.TableName}}
                {
                    // my properties...
                }
            }
            """);
    }
}