We got the great 'Domain Model Enumeration Designer' in the DSL tools to design new enums and use them as value properties of classes. But I have some value properties on my DSL elements on which I want to use an already existing enum type. Like for example the 'System.DayOfWeek' enum.

There is some kind of mechanism for this for the simple types: you can point to a namespace and type in the name of the type. Is there something similar for enums? Sure I can look up the literals in the documentation and type in al these literals in the Enum Designer, but that's quite time consuming.

Gerben [Avanade]

Hi Gerben,

To use an existing enum, do the following:

- Select the property in question on the domain model designer.

- In the property-grid, click on the drop-down for "Type"

- Select "New Simple Type..." in the drop-down.

- In the dialog, enter "System" for Namespace and "DayOfWeek" for and Name. Hit OK.

Let me know if this doesn't work for you.

Thanks,
George Mathew
DSL Tools Team

Hi George,

Hi Gerben,

I see the issue now. My fault for not giving you full information. When you choose a 'New Simple Type..." for the Type of your property, the 'Custom storage' for that property is also set to true (look for 'Custom storage' on the property grid when the property is selected). When 'Custom storage' is true, it means that you are responsible for providing storage for this property. To do that, add a partial declaration for your class and add the code below:

namespace CompanyName.ProjectName.Language3.DomainModel
{
public partial class ExampleClass
{

System.DayOfWeek property1Storage;

public override object GetValueForCustomStoredAttribute(Microsoft.VisualStudio.Modeling.MetaAttributeInfo attribute)
{
if (attribute.Id == Property1MetaAttributeGuid)
{
return property1Storage;
}
return base.GetValueForCustomStoredAttribute(attribute);
}

public override void SetValueForCustomStoredAttribute(Microsoft.VisualStudio.Modeling.MetaAttributeInfo attribute, object newValue)
{
if (attribute.Id == Property1MetaAttributeGuid)
{
property1Storage = (System.DayOfWeek)newValue;
}
else
{
base.SetValueForCustomStoredAttribute(attribute, newValue);
}
}
}
}

The experience for doing this will be much better in the next release. Using a external enum won't require your property to be custom stored. Also, if you have a custom stored property, the API for implementing it will be much cleaner and the code will throw a compile-error if the storage is not implemented (unlike the obscure runtime error you got).

Hope this helps.

Thanks,
George Mathew
DSL Tools Team

Cool, that works fine George. Thanks!

Though you guys make me wanna die for the V1 release

Gerben [Avanade]

HI,

It's a little different these days.

What you're looking for now is to add a new external type matching your existing enumeration using the DSL Explorer window. You can then choose this external type as the type of your property.