how about add pointer support in binding Form Params?

[qazqwe1596357]

I see code in https://github.com/gin-gonic/gin/blob/master/binding/form_mapping.go, we can only support value field bind, do not support pointer type.

// example
type Params struct {
  Pa string `form:"pa"`  // which can success bind via form_mapping
  Pb *string `form:"pb"`  // which cannot bind via form_mapping
}

The reason is fieldKind in "func setWithProperType()" have not pointer type.

Supporting pointer fields bind is useful we can easy know whether we pass the param. if we not passing it, it will keep nil value.
In Json Unmarshal can process pointer field also.

So do you think supporting pointer field parse in binding/form_mapping.go is a good idea?

[ritoon]

looks done did you test the new gin version
2282be0#diff-e1ee2d6085c74d622d08bb3927e7036c

[qazqwe1596357]

The response is too fast! Thanks a lot~

[appleboy]

Implemented in #1336

[ivanovaleksey]

Is it possible to differentiate between a boolean pointer parameter being nil, true, or false?
If I don't set the parameter in a query it results to false but I would like it to be nil.
Is there a way to explicitly set pointer parameter to nil?