Referencing type that is in another assembly causes "the type is defined in an assembly that is not referenced" error in Razor.Compile()

Question

We are currently using the Razor View engine to render out HTML (outside of an ASP.NET MVC project). Everything has been working okay until today when I added an enum type to my model that resides in another assembly. Now when I compile, I get the following error:

"RazorEngine.Templating.TemplateCompilationException was unhandled
HResult=-2146233088 Message=Unable to compile template. The type 'ClassLibrary1.MyClass.MyEnum' is defined in an assembly that is not referenced. You must add a reference to assembly 'ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'."

I was able to reproduce this error in a simply console application that references a type from an external DLL:

Template:

@model RazorExample.MyModel  

<div>  
    @if(Model.EnumValue == ExternalLib.MyEnum.Val1) { <p>My value is 1</p> }  
</div>  

Enum (defined in ExternalLib):

namespace ExternalLib   
{  
    public enum MyEnum  
    {  
        Val1 = 1,  
        Val2 = 2  
    }  
}  

Model:

using ExternalLib;  

namespace RazorExample  
{  
    public class MyModel  
    {  
        public String Name { get; set; }  
        public MyEnum EnumValue{ get; set; }  
    }  
}  

Code to compile the template:

Razor.Compile(template.ToString(), "MyTemplate");  

I have also tried adding a "@using ExtneralLib;" to the template but that results in an error that the type "ExternalLib" could not be found. I have seen one or two other posts regarding something similar (Razor-based view doesn't see referenced assemblies) but this is not in the context of a web application. Any help is appreciated.

EDIT
I spoke a little too soon that this fixed my error yesterday. It fixed my error in my test app but when I went to update my code, it did not work. After looking at it a bit more, I realized my model was a little more complicated.

I have updated my sample app accordingly:

Model:

public class MyModel
{
    public String Name { get; set; }
    public ParentClass ParentClass { get; set; }
}

ParentClass:

namespace ExternalLib
{
    public class ParentClass
    {
        public string Name { get; set; }
        public ChildClass ChildClass { get; set; }
    }
}

ChildClass:

namespace ExternalLib
{
    public class ChildClass
    {
        public enum MyEnum
        {
            Val1 = 1,
            Val2 = 2
        }
    }
}

Model:

@model RazorExample.MyModel
<div>
    @if(Model.ParentClass.ChildClass.EnumValue == ExternalLib.ChildClass.MyEnum.Val1) { <p>My value is 1</p> }  
</div>

With this code, if I add the @using ExternalLib; statement into the model, I get the error "Unable to compile template. The type or namespace name 'ExternalLib' could not be found (are you missing a using directive or an assembly reference?)"

If I leave the @using statement out, I get the exception "Unable to compile template. The type 'ExternalLib.ParentClass' is defined in an assembly that is not referenced. You must add a reference to assembly 'ExternalLib, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'."

FIX (or workaround at least)
I was able to fix this in the code I am trying to get working by creating a separate model and template for the child class and using an @Include statement in the template to import it in. I can post that code if anyone is interested but I fear I am already a little long on the post.

Answer 1

There are two things wrong in your code:

1: You need to specify the type of your model object when calling Razor.Compile(...):

Razor.Compile(template.ToString(), typeof(MyModel), "MyTemplate");

2: Your template checks the value of ExternalLib.MyEnum == ExternalLib.MyEnum.Val1 but your model's enum value property is MyNestedEnum, not MyEnum.

Change your template to the following:

@model RazorExample.MyModel  

<div>  
    @if(Model.MyNestedEnum == ExternalLib.MyEnum.Val1) { <p>My value is 1</p> }  
</div>  

HTH.