Using T4 templates in Entity framework

T4 stands for Text template transformation toolkit which is a template-based code generation engine built into Visual Studio. It is available in Visual studio from Visual Studio 2008 and higher version of Visual Studio. T4 engine allows you to generate C#, T-SQL, XML or any other text files by using ASP.NET – ASPX template like syntax. T4 template has .tt extension.

For example, TextTemplate.tt T4 template has the following code:

<#@ template language="C#" #>
<#@ assembly name="System.Core" #>
<#@ import namespace="System.Text" #>
<#@ output extension=".txt" #>
<# Write("T4 templates with EF!"); #>

The T4 template processor will transform above T4 template code into a text file having extension .txt by executing the code and processing directives inside.

T4 templates with EF!

T4 templates with Entity framework

T4 templates in entity framework are used to generate C# or VB entity classes from EDMX files. Visual Studio 2013 or 2012 provides two templates- EntityObject Generator and DBContext Generator for creating C# or VB entity classes. The additional templates are also available for download.

To use one of these templates, right-click on the design surface of an .edmx file and select the "Add Code Generation Item" command as given below-

Selecting the command will launch a dialog box allowing you to select one of the installed code-generation items, or to search for new items online.

Selected template will generate the C# or VB code files i.e. entity and context classes as given below.

What do you think?

I hope you will enjoy the T4 template while working with EF. I would like to have feedback from my blog readers. Your valuable feedback, question, or comments about this article are always welcome.

Further Reading