gin binds the request body to different structures
The conventional method of binding the request body is used c.Request.Body
and cannot be called multiple times
type formA struct {
Foo string `json:"foo" xml:"foo" binding:"required"`
}
type formB struct {
Bar string `json:"bar" xml:"bar" binding:"required"`
}
func SomeHandler(c *gin.Context) {
objA := formA{}
objB := formB{}
// This c.ShouldBind consumes c.Request.Body and it cannot be reused.
if errA := c.ShouldBind(&objA); errA == nil {
c.String(http.StatusOK, `the body should be formA`)
// Always an error is occurred by this because c.Request.Body is EOF now.
} else if errB := c.ShouldBind(&objB); errB == nil {
c.String(http.StatusOK, `the body should be formB`)
} else {
...
}
}
Similarly, you can usec.ShouldBindBodyWith
func SomeHandler(c *gin.Context) {
objA := formA{}
objB := formB{}
// This reads c.Request.Body and stores the result into the context.
if errA := c.ShouldBindBodyWith(&objA, binding.JSON); errA == nil {
c.String(http.StatusOK, `the body should be formA`)
// At this time, it reuses body stored in the context.
} else if errB := c.ShouldBindBodyWith(&objB, binding.JSON); errB == nil {
c.String(http.StatusOK, `the body should be formB JSON`)
// And it can accepts other formats
} else if errB2 := c.ShouldBindBodyWith(&objB, binding.XML); errB2 == nil {
c.String(http.StatusOK, `the body should be formB XML`)
} else {
...
}
}
c.ShouldBindBodyWith
Store the body in the context before binding, which has a slight impact on performance, so if you want to call it immediately, you should not use this method- This feature is only available in these formats -
JSON
,XML
,MsgPack
,ProtoBuf
. For other formats,Query
,Form
,FormPost
,FormMultipart
, it may bec.ShouldBind()
called multiple times without affecting performance