Try to bind body into different structs
The normal methods for binding request body consumes c.Request.Body
and they
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 {
...
}
}
For this, you can use c.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
stores body into the context before binding. This has
a slight impact to performance, so you should not use this method if you are
enough to call binding at once.- This feature is only needed for some formats —
JSON
,XML
,MsgPack
,ProtoBuf
. For other formats,Query
,Form
,FormPost
,FormMultipart
,
can be called byc.ShouldBind()
multiple times without any damage to
performance (See #1341).