### Problem

What needs to happen is to be able to crosswalk between the two entirely different classes

**From**: [`Microsoft.AspNet.Scaffolding.Core.Metadata.PropertyMetadata`][1] 
**To**: [`System.Reflection.PropertyInfo`][2]


The `PropertyMetadata` class provided by ASP.NET Scaffolding exposes a relatively limited data, and no direct link to the original type or it's attributes.

> **Here's a comparison of the two properties** :
> [![Property Comparison][3]][3]
> (click for full res)

*because, honestly, why spend all this time working with a custom model generator without having access to the rich world of data provided by System.Reflection*

### Solution

1. We're going to build a T4 helper method right inside of our normal web assembly. This is just any `static` method that can be consumed externally. We'll register it later inside of the T4 file so it can actually be used.

 So add a file like this anywhere in your project:

 `UtilityTools.cs`

 
 
 using System;
 using System.Reflection;
 using System.ComponentModel.DataAnnotations;
 namespace UtilityTools
 {
 public static class T4Helpers
 {
 public static bool IsRequired(string viewDataTypeName, string propertyName)
 {
 bool isRequired = false;
 
 Type typeModel = Type.GetType(viewDataTypeName);
 if (typeModel != null)
 {
 PropertyInfo pi = typeModel.GetProperty(propertyName);
 Attribute attr = pi.GetCustomAttribute<RequiredAttribute>();
 isRequired = attr != null;
 }
 
 return isRequired;
 }
 }
 }

2. Now let's register it by adding your assembly to the **`Imports.include.t4**: file:

 
 
 <#@ assembly name="C:\stash\cshn\App\MyProj\bin\MyProj.dll" #>

 [![Imports.include.t4][6]][6]

 Much in the same way that other assemblies are loaded, this actually gives us access to any static methods inside of whatever assembly we've loaded, minimally providing accessing to `UtilityTools.T4Helpers.IsRequired`

3. Make sure you Rebuild your application (and possibly reload Visual Studio)
4. Now we can make use of that inside any of our T4 templates like this:

 
 
 <#= UtilityTools.T4Helpers.IsRequired(ViewDataTypeName, property.PropertyName) #>

 [![IsRequired Helper usage][7]][7]

**Further Reading**:

The above solution is heavily adapted from the following articles & questions:

* [MVC 5 T4 Templates and View Model Property Attributes][4]
* [MVC 4 custom data annotations read in T4 scaffolding][5]
* [Get scaffolder to generate fields in specific order][8]

>**Tip**: Debugging T4 templates can sometimes be a bear, so I wrote this test template which helps dump out information from the model so you can easily evaluate ASP.NET is using as values to hydrate `PropertyMetadata`
> **Gist**: https://gist.github.com/KyleMit/fc9ccfbc2af03462d660257103326509

---

> **Note**: `Type.GetType("Namespace.Qualified.TypeName")` [only works when the type is found in either mscorlib.dll or the currently executing assembly][9]. If your model is part of a business library, you either have to use a [`AssemblyQualifiedName`][10] [like this][11]:
>
> <pre><code>Type.GetType("Namespace.Qualified.TypeName,DllName")</code></pre>
> or you can search through [all of the currently executing assemblies like this][12]:
>
 public static Type GetType(string typeName)
 {
 var type = Type.GetType(typeName);
 if (type != null) return type;
 foreach (var a in AppDomain.CurrentDomain.GetAssemblies())
 {
 type = a.GetType(typeName);
 if (type != null)
 return type;
 }
 return null;
 }
> in order for this to work, you'll have to add any business libraries that contain classes to the list of imported assemblies (same as we did earlier in the imports.t4 file):
> <pre><code>&lt;#@ assembly name=&quot;C:\stash\cshn\App\MyProj\bin\MyProj.Business.dll&quot; #&gt;</code></pre>


 [1]: https://msdn.microsoft.com/en-us/library/Microsoft.AspNet.Scaffolding.Core.MetaData.PropertyMetaData#Properties "Microsoft.AspNet.Scaffolding.Core.MetaData.PropertyMetaData"
 [2]: https://msdn.microsoft.com/en-us/library/System.Reflection.PropertyInfo#Properties "System.Reflection.PropertyInfo"
 [3]: https://i.stack.imgur.com/XKU2K.png
 [4]: https://johniekarr.wordpress.com/2015/05/16/mvc-5-t4-templates-and-view-model-property-attributes/
 [5]: https://stackoverflow.com/a/30279416/1366033
 [6]: https://i.stack.imgur.com/66TTK.png
 [7]: https://i.stack.imgur.com/SF03M.png
[8]: https://stackoverflow.com/q/40530823/1366033
[9]: https://stackoverflow.com/a/1825156/1366033
[10]: https://msdn.microsoft.com/en-us/library/System.Type.AssemblyQualifiedName "System.Type.AssemblyQualifiedName"
[11]: https://stackoverflow.com/a/6465096/1366033
[12]: https://stackoverflow.com/a/11811046/1366033

I am trying to create a replacement T4 template for the MVC5 Controller.
I have everything working except for one issue.

I need to generate code for each property in the Model, and looping through `ModelMetadata.Properties` is actually really easy. However it is not an array of `PropertyInfo`s. Rather it is an array of `PropertyMetadata` which doesn't seem to have any information about whether a property is required or not or if its type is nullable or not. So properties in your model of type `int` and `int?` both show up as type `System.Int32`.

Furthermore there is no way to get a list of `PropertyInfo`s being that you can't really get a `Type` Object for the model which you are scaffolding, being that only the short type name is passed to the template.

In summation: Is there any way to know in a T4 template if a property is nullable?