[EF core] How to register all value converters in project?

[BlackBearFTW]

Hi,

I am using Vogen's value objects in multiple places and I want to support conversion with entity framework core, now the documentation says that you don't need to specify a value convertor for structs, is this correct?

Is there any way to configure all value converters automatically in DbContext ConfigureConventions?

Sorry if this is in the docs, I couldn't find a clear answer. I know you can have a marker class and add all value objects to that with EfConverter, but that still requires you to add all value objects above it.

[SteveDunn]

Hi, you can do this:

protected override void ConfigureConventions(
    ModelConfigurationBuilder configurationBuilder)
{
    base.ConfigureConventions(configurationBuilder);

    configurationBuilder.RegisterAllInVogenEfCoreConverters();
}

(taken from https://stevedunn.github.io/Vogen/efcoreintegrationhowto.html)

[BlackBearFTW]

Yes I saw that, as said, you still need to attribute all of your value objects to that marker interface, I was wondering if there is a way to do it automatically and why doesn't Vogen just generate a RegisterVogenValueConverters method for ConfigureConventions?

I also read this: It is possible to use value objects (VOs) in EFCore. Using VO structs is straightforward, and no converter is required. Using VO classes requires generating a converter.

That means structs don't need value converters?

[SteveDunn]

Apologies, yes, you still need the marker interface.
And yes, for structs, no conversion is needed. If you remove the converters from the marker classes in the EFCore scenario in the sample Consumers solution, you'll see that the scenario runs fine without them.

It's challenging for Vogen to know what value object will be used in EFCore, which is why the marker classes are needed allowing the user to specify them.

[SteveDunn]

Interesting, but this doesn't capture value objects which don't have an EFCore conversion attribute but where the global configuration does.

[BlackBearFTW]

Yeah but does that matter?

You already do something similar for the ef core value converter itself, so at that point you know that you need to generate a ef core value convertor and I am guessing this looks both at the attribute and the global configuration:

https://github.com/SteveDunn/Vogen/blob/main/src%2FVogen%2FGenerators%2FConversions%2FGenerateEfCoreExtensions.cs

Look at the ef core flag, you could just do something similar only then for the model binder code I shared with you.

This would make registering these convertors a lot easier, you could probably do something similar for other convertors, like you could make a RegisterAllSqlTypes extension method for Dapper, etc

[SteveDunn]

You make a good point. I'll take a look - many thanks!

[BlackBearFTW]

No problem, again this would be great!

And if you want to take it a step further you could probably even make it project specific, so all vogen objects with an ef core value converter in the MyApp.Web project will be under an extension method called .RegisterVogenMyAppWebValueConvertors() or something similar, so you can separate layers.

Maybe that is something for the future tho.

[BlackBearFTW]

Hi!

Did you manage to figure out if this will be implemented?

I also wanted to note that the first statement on your website on the "Integration with Entity Framework Core" is false, you still need a value convertor even if your value object is a struct.