ModelBaseClass (for individual model)

[quiznaut]

It would be helpful to be able to specify base class for each individual model, in addition to being able to specify ModelsBaseClass for all models.

My situation is this: following some advice I saw in a blog that "compositions are the way to go" and that it's possible that document type inheritance may be deprecated in a future Umbraco version, I set up no inheritance among my document types.

My thinking has evolved, and now I'd like to add some common functionality to just some of those document types. Perfect use for inheritance, but I don't have any.

Alternatives I considered, all of which have problems:

• Adding inheritance after-the-fact doesn't seem possible in the Umbraco backoffice, so this is not really an alternative. Maybe I'm wrong?
• I could add inheritance to the document types with a set of SQL queries I found in our.umbraco, but I am hesitant to use SQL to modify entries in the database of an application that's meant to be accessed only via API.
• I could use ModelsBaseClass, but it would apply to all my document types. That smells bad, and precludes me from later differentiating behavior through the mechanism of a base class.
• I tried to set the base class in a partial in the ModelsDirectory. Since the base class is already set to PublishedContentModel in the .generated.cs file, the compiler yells at me. Rightfully so.

It seems to me that the best solution for a problem like this, and indeed a good way to get more value out of compositions in general, is to allow specification of base class on a model-by-model basis.

[zpqrtbnk]

Hey,

There is no way to add inheritance after-the-fact in the backoffice. In can be done by messing with the database, but you really have to know what you're doing. And besides, maybe this inheritance does not make sense from a "content" point of view if it's essentially a technical inheritance used to expose some common functionnality.

Adding the base class to all document types does indeed smell bad.

Which leaves us with changing the base class for some models. The next version should support specifying a base class per model, but it's been in progress forever and is not going to ship soon. That being said, I think that you should be able to specify a base class in your partial:

public partial class MyModel : MyBaseClass
{ ... }

And the ModelsBuilder should detect it and not set the base class in the generated code. Of course, you do need to re-generate the code, so that the ModelsBuilder can do it. But I'm pretty sure it should work. Can you try again?

[quiznaut]

Thank you, Stephan, that worked. It was important to:

1. Include the file with the partial class (that inherits from the custom base class) in the same folder as the .generated.cs files. In my case, that's the folder I specified via the .ModelsDirectory key.
2. Generate models before attempting to compile.

I think I did the first bit back in February when I originally posted this question. But it's likely I immediately tried to compile, and did not re-generate the models. That's what tripped me up.

Sorry it's taken me so long to get back to you.

[quiznaut]

I've finally picked this up again and found that, although I can set the base class after-the-fact, and ModelsBuilder picks it up, if my base class needs to implement any of compositions that the derived classes implement, ModelsBuilder doesn't take that into account. It generates all of the composition properties in the derived class without regard to the base class, effectively hiding the base-class properties.

As a side note, for my current project my workaround was to use document type inheritance. Unfortunately, it's not compatible with composition, as documented here: U4-7596