Is there a way to validate URL params?

e.g.

r.GET("/:foo/*bar", myFunc)

How can I validate foo and bar?

It would be nice if c.Bind() method could fall back (query params, form params, url params) - maybe introducing a 'url' tag:

type MyParams struct {
    Foo string `url:"foo"`
    Bar string `url:"bar`
    Download bool `form:"dl"`
}

Comment From: singggum3b

I'm wondering this too ?

Comment From: javierprovecho

@miketonks that's an interesting feature, however the bind validator would need the fingerprint of the path, or just try to un marshall the c.Params(...) into an struct. need to think about it...

Comment From: thinkerou

We can get these value using c.Param("foo") and c.Param("bar"), but I don't understand we need to validate what? The type of value which got by c.Param("foo"), right?

Comment From: splokhikh

Will it be implemented? I'm interest it too

Comment From: Szasza

@javierprovecho do you happen to have any updates on this one?

Comment From: thinkerou

@Szasza can you describe the issue requirement? thanks!

Comment From: Szasza

@thinkerou thank you for the ultra-quick response, it is much appreciated.

Use case: having an URL path like /books/:id, where ID is let's say an UUID. I would like to be able to use struct-based binding using tags to validate the URL path parameter id.

Problem: Currently the above is not possible in a straightforward way, because: * the bind and shouldBind functions only exist for query parameters, and request bodies, but not for URL path parameter * using the context there is no way to mutate the request query or body, which would enable to put the URL params into the request query/body and use the existing binding functions

One workaround I can think of from the top of my head is creating a new http.Request, copying the URL path parameter names and values into the new request's query parameters, and running bindWith using that, but it is extra code in each handler which could be simplified.

I hope the above helps.

Comment From: thinkerou

wip demo: #1612

or just try to un marshall the c.Params(...) into an struct

Not un marshall it into struct, but traverse it and mapForm its element.

Comment From: Szasza

@thinkerou thank you for the quick WIP demo, it works perfectly fine with valid values.

I am unsure if the error handling is considered as finalised in the changeset, but if I set uuid as the binding's value, and send an invalid uuid as the path parameter value, it yields an unhandled panic.

Thank you again.

Comment From: thinkerou

@Szasza you are welcome! uuid likes xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, and uri is /rest/n/:uuid, now visit /rest/n/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx will trigger binding, but how should check it? because input uuid is a string. thanks!

Comment From: Szasza

@thinkerou I think there is a misunderstanding here, please allow me to clarify it.

When I bind let's say the query parameters of a request, there are two tags that I use for the request struct's fields: - form:"id" - it binds the id query param to the struct field - binding:"uuid" - this is a pass-through to validator.v8, the value is validated against the uuid validation rule.

Is it possible to have the same pass-through for the binding tag in case of an uri:"id" binding as well and return a proper validation message instead of a panic? This would be useful since the router does not support regexp-based URI parameter matching.

I hope the above helps, please let me know if further clarification is needed, and thank you again.

Comment From: thinkerou

@Szasza thanks! Now #1612 have supported bind uri params, please help me review, thanks everybody!

Comment From: Szasza

@thinkerou my pleasure, thank you for the quick implementation, it is much appreciated :smile:

Comment From: axiaoxin

Why not support the type of params specified in URL? like

router.GET("/post/<int:post_id>", Handler)

Comment From: thinkerou

@axiaoxin IMO, that is too complex.

Comment From: miketonks

Thanks for adding this feature, it looks great.

If anyone is interested we solved the problem another way, which can be used on top of / alongside gin validation.

See: https://github.com/miketonks/swag-validator

Comment From: thinkerou

1612 merged!

Comment From: dszakallas

Thanks! This is great. Why not add BindUri ~and MustBindUri~ too?

Comment From: halink0803

When there will be a new release? This feature is useful and I don't want to fork to the latest commit.

Comment From: thinkerou

Thanks! This is great. Why not add BindUri and MustBindUri too?

@dszakallas I will add it. thanks!

When there will be a new release? This feature is useful and I don't want to fork to the latest commit.

@halink0803 1.4 version on February 28, 2019, and publish release need to @javierprovecho help.

Comment From: thinkerou

@dszakallas #1694 add BindUri.

Comment From: halink0803

@thinkerou Thank you for quick response, I think we will fork latest commit by then.

Comment From: cappuccino5

please there problem deal? I too like use it

Comment From: thinkerou

@cappuccino5 what's mean?

Comment From: SilkageNet

please how bind uri to map

Comment From: zhujinhe

Btw, should Uri be all uppercase?

Comment From: asbjornu

If I want a model to be bound to both form and uri parameters, do I need to call several Bind methods? Calling ShouldBind() doesn't seem to bind uri parameters.

Comment From: hrQAQ

@asbjornu Maybe you need to try ShouldBindWith()

this doc has some more info !

Gin Binding for URL Params

1612 merged!