Gin: Asking for a way to bind a struct ignoring binding tage

[fwhezfwhez]

Hello, is there a way to bind ignoring binding tag but don't set global binding false ?
Why I ask this?
In the update and create cases for a model, I want to use the same model. For instance:

type User struct{
Username string `json:"username" binding:"required"`
Field2 string 
Field3 string
}

in the case of creating , username is required.However in the case of updating, field username can be ignored. The solution of designing two almostly the same models is really bothering.

I wonder can gin add a function BindWithoutBindingTag(interface{}) like:

func (c *gin.Context) BindWithoutBindingTag(interface{}) error{
}

This is my case for json:

BindWithoutBindingTag(c *gin.Context, in, dest interface{}) error{
    if c.ContentType() != "application/json" {
        return errors.New("'BindWithoutBindingTag' only serves for application/json not for "+ c.ContentType())
    }
    buf,e :=ioutil.ReadAll(c.Request.Body)
    if e!=nil {
        return e
    }
    c.Request.Body = ioutil.NopCloser(bytes.NewReader(buf))
    return json.Unmarshal(buf, dest)
}

[b3lc0d3]

It's good idea. @thinkerou what do you think about? I can create PR for the feature.

[fwhezfwhez]

@b3lc0d3 yes,yes,
by the way,
Sometimes I need to read out from request.body,however after you've bind in a former middleware ,then it'll throws an EOF error if you bind again afterwards, like:

c.Bind(&o1)  // success
c.Bind(&o2)  // EOF

Can gin provide a method to bind repeated?
here is my personal solution for json however not involved to the officals regardless of some offical tags:

BindRepeatedly(c *gin.Context,dest interface{}) error{
    if c.ContentType() != "application/json" {
        return errors.New("'BindRepeatedly' only serves for application/json not for "+ c.ContentType())
    }
    buf,e :=ioutil.ReadAll(c.Request.Body)
    if e!=nil {
        return e
    }
    c.Request.Body = ioutil.NopCloser(bytes.NewReader(buf))
    return json.Unmarshal(buf, dest)
}

[thinkerou]

@fwhezfwhez @b3lc0d3 please see https://github.com/gin-gonic/gin#model-binding-and-validation, you can use binding:"-".

[fwhezfwhez]

@thinkerou

type User struct{
    Username string `binding:"-"`
} 

how to use a single model to fits both cases:
createUser: username required. Username stringbinding:"required"``

updateUser: username optional. Username stringbinding:"-"``

[mosleim]

@fwhezfwhez any update about single model to fits your both cases?

[fwhezfwhez]

@thinkerou @mosleim

type User struct{
    Username string `binding:"required"`
}


c.BindIgnoreBindTag(&user)   // will not require username
c.Bind(&user)  // require username