I just got stuck with this in my tinkerimg with minimal APIs, I was trying to do this with middleware, but it is impossible to extract those generic parameters through HttpContext. Thank you very much for showing this!
Thanks Shawn, I really like the idea of this style of validation over the attribute-based approach. One question though, at 12:26, what's the benefit of .OfType().FirstOrDefault(a => a?.GetType() == typeof(T)); ? Couldn't you simply do .OfType().FirstOrDefault(); ? It seems like the condition inside FirstOrDefault is just repeating the work of OfType
Hi Shawn, thanks for the great video. i just wanna ask you how to make it generic register AddValidatorsFromAssemblyContaining(typeof(ClassValidator)) ?
You can use AddValidatorsFromAssembly or one of the other methods that will look at it more globally. But I don't suggest looking at all of the types to find the validators.
For these small examples, VSCode is quicker to get my ideas in the video. I use Visual Studio much more often for general .NET projects. Rider is a great product. I don't see the benefit since i'm already on Windows. I also don't care for the constant nagging for every suggestion that Resharper thinks I need. But if it helps you, that's awesome. If you're curious my longer take, see my video about whether VSCode is ready for full-time .NET Dev: th-cam.com/video/71Hx2pfgym8/w-d-xo.html
I am using a very similar pattern, but finding re-use difficult when I don't know which of the context Arguments I want to validate. My request has multiple Guids and sometimes my Object Id is the first parameter, other times it may be the second or third. You are using .FirstOrDefault(a => a?.GetType() == typeof(T)... How could you cater for cases where it is not the first parameter?
I know this looks like it has to be the first parameter, but it doesn't. Remember, you're validating a specific Type (T), so this is finding the first (or default) that has that type. If you're validating more than one parameter of the same type, you could get a collection from this, but I can't imagine that is actually what you're doing. If you look at the source: github.com/shawnwildermuth/codingshorts/blob/742e661714885bf8652760f8e7c1c625b1ec66af/minimal-validation/after/ValidationFilter.cs#L11
@@swildermuth i do have multiple parameters of the same type, in my case it’s 3 Guids coming from route parameters. however, I have now found a solution. By building the filter from the EndpointFilterFactory I get access to the EndpointFilterFactoryContext which gives me the parameters collection complete with names, types snd positions. I can therefore look up the position based on the parameter name and I can re-use the filter irrespective of where in the parameter list my input value is coming from. Thanks
@@swildermuth In very basic terms. You would create your abstract validator as you've already done. Next, you will create a ValidationBehaviour which implements IPipelineBehavior provided by mediatr. Next you will register your pipeline behaviors in DI. Now, when a request comes in an you send it (command or query) the validator for that request will be run before the handler is called. Other behaviors may also run, and caching or logging or auth whatever. Very common is to have the validationbahavior throw a validation exception and then have a middleware that sees that and coverts it to a problem response. I prefer to return a Result type. But what ever works. I'm sure if you search for mediatr pipeline validation behavior you can find more detailed info.
Such a great simple video. Appreciate it thank you
Very informative video! I am starting to sway towards minimal APIs now, thanks to your videos. Keep it up Shawn!
Great to hear!
Great effort. Thank you for sharing.
Ghanks!
Thanks Shawn!
I really like your presentation style. Nice video.
Just discovered your channel, I already love it!
Great explanation, thanks a lot!
You are welcome!
Was helpful, thanks!
I just got stuck with this in my tinkerimg with minimal APIs, I was trying to do this with middleware, but it is impossible to extract those generic parameters through HttpContext. Thank you very much for showing this!
Great, though this technique only works for .NET 7.
Thanks Shawn, I really like the idea of this style of validation over the attribute-based approach.
One question though, at 12:26, what's the benefit of .OfType().FirstOrDefault(a => a?.GetType() == typeof(T)); ?
Couldn't you simply do .OfType().FirstOrDefault(); ?
It seems like the condition inside FirstOrDefault is just repeating the work of OfType
Yes, that would work.
Hi Shawn, thanks for the great video. i just wanna ask you how to make it generic register AddValidatorsFromAssemblyContaining(typeof(ClassValidator)) ?
You can use AddValidatorsFromAssembly or one of the other methods that will look at it more globally. But I don't suggest looking at all of the types to find the validators.
@@swildermuth i finally using SharpGrip.. thanks for the answer
Working with C# in VS Code looks extremely inconvenient; What makes you use it over Rider?
For these small examples, VSCode is quicker to get my ideas in the video. I use Visual Studio much more often for general .NET projects. Rider is a great product. I don't see the benefit since i'm already on Windows. I also don't care for the constant nagging for every suggestion that Resharper thinks I need. But if it helps you, that's awesome. If you're curious my longer take, see my video about whether VSCode is ready for full-time .NET Dev:
th-cam.com/video/71Hx2pfgym8/w-d-xo.html
I am using a very similar pattern, but finding re-use difficult when I don't know which of the context Arguments I want to validate. My request has multiple Guids and sometimes my Object Id is the first parameter, other times it may be the second or third.
You are using .FirstOrDefault(a => a?.GetType() == typeof(T)...
How could you cater for cases where it is not the first parameter?
I know this looks like it has to be the first parameter, but it doesn't. Remember, you're validating a specific Type (T), so this is finding the first (or default) that has that type. If you're validating more than one parameter of the same type, you could get a collection from this, but I can't imagine that is actually what you're doing. If you look at the source:
github.com/shawnwildermuth/codingshorts/blob/742e661714885bf8652760f8e7c1c625b1ec66af/minimal-validation/after/ValidationFilter.cs#L11
@@swildermuth i do have multiple parameters of the same type, in my case it’s 3 Guids coming from route parameters.
however, I have now found a solution. By building the filter from the EndpointFilterFactory I get access to the EndpointFilterFactoryContext which gives me the parameters collection complete with names, types snd positions. I can therefore look up the position based on the parameter name and I can re-use the filter irrespective of where in the parameter list my input value is coming from. Thanks
Is doing validation with Mediatr pipelines out of vouge with Minimal API now?
When was it in vogue. I haven't done it before. Can you explain?
@@swildermuth In very basic terms.
You would create your abstract validator as you've already done.
Next, you will create a ValidationBehaviour which implements IPipelineBehavior provided by mediatr.
Next you will register your pipeline behaviors in DI.
Now, when a request comes in an you send it (command or query) the validator for that request will be run before the handler is called. Other behaviors may also run, and caching or logging or auth whatever.
Very common is to have the validationbahavior throw a validation exception and then have a middleware that sees that and coverts it to a problem response.
I prefer to return a Result type. But what ever works.
I'm sure if you search for mediatr pipeline validation behavior you can find more detailed info.