T4 Templates Are Free to Use

T4 (Text Template Transformation Toolkit) templates are completely free to use. They are included as a built-in feature in all editions of Visual Studio, including the free Visual Studio Community Edition.

Availability Across Visual Studio Editions

Cost Breakdown for T4 Templates

What's Included for Free

With T4 templates, you get:

1. Design-time templates: Generate code during development
2. Runtime templates: Generate code at application runtime
3. Template editor: Basic editor support in Visual Studio
4. Integration with MSBuild: Automate code generation during builds
5. Full access to the T4 engine: Create custom templates for any purpose

Additional Tools (Some May Have Costs)

While T4 itself is free, there are some optional add-ons that might have costs:

1. Enhanced T4 editors: Some third-party extensions for better T4 editing experience may be paid
2. Visual Studio extensions: Certain extensions that enhance T4 functionality might be commercial
3. Third-party T4 template packs: Pre-built template collections from vendors might be paid

Using T4 in .NET Core/.NET 5+ Projects

For .NET Core and newer .NET versions:

1. Visual Studio integration: Free with any Visual Studio edition
2. Command-line usage: Free via the dotnet-t4 tool
3. Cross-platform support: Free, though best experience is on Windows with Visual Studio

Licensing Considerations

• No royalties: You don't need to pay royalties for code generated by T4
• No runtime licensing: No licensing requirements for deploying applications with T4-generated code
• Open usage: You can use T4 in both commercial and non-commercial projects

Bottom Line

T4 templates are a free, built-in feature of the .NET ecosystem. You don't need to purchase any additional licenses or subscriptions to use them in your .NET Core API projects for generating CRUD operations or any other code generation tasks.

The only potential cost would be if you choose to purchase Visual Studio Professional or Enterprise for their additional features, but T4 templates themselves are fully functional even in the free Community Edition.

Setting Up T4 Templates for Vendor and Brand Tables

Let me walk you through setting up T4 templates for your Vendor and Brand tables with a complete example.

Step 1: Set Up Your Project

First, ensure you have the necessary NuGet packages:

Step 2: Create Your T4 Template Files

Create a Templates folder in your project and add the following T4 template files:

Model Template (EntityModel.tt)

Controller Template (EntityController.tt)

Repository Interface Template (IEntityRepository.tt)

Repository Implementation Template (EntityRepository.tt)

Step 3: Create a T4 Template Runner

Create a console application or a class in your project to run the templates:

Step 4: Run the Code Generator

You can call the code generator from your application startup or create a separate tool:

Step 5: Generated Code Examples

Here's what the generated code will look like:

Generated Vendor Model

Generated Brand Model

Generated Vendor Controller

Step 6: Register Services in Startup.cs

Don't forget to register your repositories in your Startup.cs file:

Alternative: Visual Studio Integration

If you're using Visual Studio, you can also create T4 templates directly in your project:

1. Right-click on your project in Solution Explorer
2. Select "Add" > "New Item"
3. Search for "Text Template"
4. Add a new Text Template file (e.g., "VendorModel.tt")
5. Paste the template content
6. Save the file to generate the output

Tips for Working with T4 Templates

1. Use Visual Studio extensions: Extensions like "Tangible T4 Editor" can provide syntax highlighting and IntelliSense for T4 templates
2. Organize templates: Keep your templates in a separate folder for better organization
3. Use include files: For common code shared between templates
4. Add error handling: Include error handling in your template processing code
5. Automate generation: Consider adding code generation to your build process

This example demonstrates how to set up T4 templates for Vendor and Brand tables in a .NET Core API project. You can extend this approach to generate code for all tables in your database schema.