Go Struct and Field validation, including Cross Field and Cross Field Cross Struct validation
Yes you can get the normal validation message from the error with err.Error() to get the string representation...but if you want to build your own you can get all of the error in formation like in the examples https://github.com/go-playground/validator/blob/v9/examples/simple/main.go#L56 (errors are an array of error not a map, have to update the notes in example
(in my case the top level struct has exported structs I want to validate which has unexported fields)
saw a reference to Validatable, is that another approach?
so i could implement Validate() error on my Struct and it could take care of figuring out if it is valid returning any error
sounds like that's a lot like the user level struct validator, just with less casting (though understand that you may not be able to implement said interface)
or expose my global validator
which maybe is the better approach there :)
if you have any ideas
Looks like you have done a great job here at creating an easy to use validator that is quite fast, for using reflect.
I quickly threw together a questionable speed comparison with my validation language katydid relapse here:
katydid/katydid#6
You will see that I have spent way too much time optimizing katydid relapse.
It shows a 58x speed up in the worst case and a 1.5x speed up in the best case.
I think you could easily use relapse in the background without having your users notice.
Simply translate the reflected struct tags into a relapse expression and use that in the background.
That is if you are interested in some collaboration?
I quickly threw together a questionable speed comparison with my validation language katydid relapse here:
katydid/katydid#6
You will see that I have spent way too much time optimizing katydid relapse.
It shows a 58x speed up in the worst case and a 1.5x speed up in the best case.
I think you could easily use relapse in the background without having your users notice.
Simply translate the reflected struct tags into a relapse expression and use that in the background.
That is if you are interested in some collaboration?
Hey @awalterschulze thanks, I'll take a more in depth look, but at first glance I agree that the speed comparison is questionable
validator does a lot more than just validate, including returning detailed information on what, if anything, failed https://github.com/go-playground/validator/blob/v9/errors.go#L83 for translation, cross field validation etc...
and when you mention Disclaimer: I did take some shortcuts on BenchmarkStructComplexSuccess and BenchmarkStructComplexFailure by not including the last two fields. the last two are the ones that require runtime reflection.
but I am intrigued and am always looking to improve :)
Returning the FieldError is a great feature, which relapse does not have. It is especially hard in relapse since it supports Not of sub expressions, where expressions are necessarily just fields. Given the limitations of simply validating fields, we could have custom leave functions, which relapse supports, like myfield->isValidWithError("my error message with fieldname", eq($string, "bla")), which then adds these errors into a list that was injected at relapse compile time.
I think translations will also follow from this.
Relapse does not support cross field validation though, since this will require a memory allocation and then the expression looses speed. There are some hacks to implement cross field validation uses custom functions on the leafs.
Regarding the runtime reflection. Katydid also does runtime reflect in its reflect parser https://github.com/katydid/katydid/blob/master/parser/reflect/reflect.go . The parser is just very naive at this point, but could easily be improved. I was just too lazy to do it for this test, before more buy in.
So yes this should all be possible, but given the hacks required for error returns and cross field validation, it is less simple that I initially thought.
but still interested in taking a deeper look
Oh and I assume this would work for individual variables as well and not just structs?
justinclift @justinclift has been meaning to look into that more, but well... it hasn't happened yet
@justinclift ya looked into it when creating and there's just no way, that I have found, to get the variables name using reflection...only other thing that could be done is add another parameter for the name of the field, but that's not ideal either and doesn't work with dynamic variables. If you come up with anything though please let me know, definitely love to get better output :)
@all Guys u have this below struct
type PropertyMessage struct {
id string `form:"id" json:"id" binding:"required"`
data []map[string]interface{} `form:"data" json:"data" binding:"required" validate:"gt=0"`
}Seems like gt is not working when my POST request payload is
{
id: "abc",
data: []
}
i am expecting the request to fail throwing error data has 0 length, but my request is a success.
Forgot to mention i am using the gin library
And lowercase strings before the comparison and register your own custom validation
I need to validate field IF another field equal something