Scaffolding

Background

While working on a MVC 6 application backed by a web API application which resides in a separate project I found myself wanting a quick way to use a model as a base to generate a controller and associated CRUD razor views. If a project is using entity framework this is simple to accomplish, but since my project is using web API calls instead of entity framework scaffolding is unavailable. Instead of manually creating all the needed parts I decided to try and enable the scaffolding bits that are available in projects using entity framework.

Getting Started

The first step I took was to look at the project.json from an application using entity framework. This helped me identity the dependencies and tools that might be needed for the scaffolding process. The following are the new items from the dependencies section.

"Microsoft.VisualStudio.Web.CodeGeneration.Tools": {
  "version": "1.0.0-preview2-final",
  "type": "build"
},
"Microsoft.VisualStudio.Web.CodeGenerators.Mvc": {
  "version": "1.0.0-preview2-final",
  "type": "build"
}

And the new items from the tools section (spoiler Microsoft.VisualStudio.Web.CodeGenerators.Mvc isn’t actually needed).

"Microsoft.VisualStudio.Web.CodeGeneration.Tools": {
  "version": "1.0.0-preview2-final",
  "imports": [
    "portable-net45+win8"
  ]
},
"Microsoft.VisualStudio.Web.CodeGenerators.Mvc": {
  "version": "1.0.0-preview2-final",
  "type": "build"
}

Failed dotnet restore

With the above changes dotnet restore fails with this error:

Package Microsoft.Composition 1.0.27 is not compatible with netcoreapp1.0 (.NETCoreApp,Version=v1.0). Package Microsoft.Composition 1.0.27 supports: portable-net45+win8+wp8+wpa81 (.NETPortable,Version=v0.0,Profile=Profile259)
One or more packages are incompatible with .NETCoreApp,Version=v1.0.

I double checked that the entity framework project was using the same versions. It was indeed using the same versions, but its restore worked fine.

The fix

This is a known issue which can be found on github here. The issues is caused by Microsoft.VisualStudio.Web.CodeGenerators.Mvc in the tools sections which I finally found out is not actually needed to enable scaffolding. To be clear the only change needed in the tools section the addition of the following and Microsoft.VisualStudio.Web.CodeGenerators.Mvc is not needed.

"Microsoft.VisualStudio.Web.CodeGeneration.Tools": {
  "version": "1.0.0-preview2-final",
  "imports": [
    "portable-net45+win8"
  ]
}

Scaffolding

Right click the Controllers folder and select Add > Controllers… (this is the menu enabled by the changes above).

The above launches the Add Scaffold dialog. Here select “MVC Controller with views, using Entity Framework”. This is the only built in option that creates views. Since this project isn’t using entity framework it will require a little clean up, but it is still faster than creating the views manually.

After clicking add you will see the following screen. Select the model class to be used during the scaffold. For the data context class click the plus (+) button and enter a name (don’t spend any time on the name the resulting file will be deleted in the next step. Finally enter a controller name and click Add.

Cleaning up the scaffold

In the models folder delete the data context class that was created, TestContext in this case. The removal of the TestContext will cause errors in the TestController which can all be removed (the constructor and private field used to hold the context) and replaced with calls to whatever back end system you happen to be using in your application. Finally in the Startup class remove the last reference to the TestContext.

Wrapping up

That is all the changes that were required other than adding a reference to the test index page to the home page of the application. Not sure this is the most efficient method ever, but for me it is easyer than creating the razor pages myself manually. In the future I may do some digging and determine what is required to create my own scaffolding option.