No Bind Form Data use the pb.go was generated by .proto file when binding slice of struct in formdata request

[DenisYin66]

Issue Description

Hi all. Thank you for this project and all the great work on it.

Recently, we want to use proto file to automatically generate xxx_echo.pb.go file that can register GET/POST http echo service For example, the stuct generated by message SayHelloReq is as follows:

type SayHelloReq struct {
    Name string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
}

func RegisterHelloEchoServer(s *echo.Server, service HelloServer) {
	s.POST("/hello/", _WrapperHelloSayHello(service))
}

func _WrapperHelloSayHello(service HelloServer) echo.HandlerFunc {
     return func(ctx *echo.Context) error {
          var in SayHelloReq
          ctx.Bind(&in)          //this
          xxx  todo some logic 
     }
}

but when Simulate a form request like this：

curl \
  -X POST \
  http://localhost:1323/hello
  -d 'name=Joe' \

The default binder of echo to find this data,and the data is nil. but the form["name"] = "Joe"

form["name,omitempty"]

but i want the echo to find form["name"]. After that, can echo support the resolution of Google omitempty?

Checklist

• [ ] Dependencies installed protobuf

Expected behaviour

can echo support the resolution of Google omitempty

Version/commit

[aldas]

Hi, to bind form data you need to add form:"name" to the struct field tag. Please see the documentation about that at https://echo.labstack.com/guide/binding/

		type SayHelloReq struct {
			Name string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty" form:"name"`
		}

Full example:

func main() {
	e := echo.New()

	e.POST("/post", func(c echo.Context) error {
		type SayHelloReq struct {
			Name string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty" form:"name"`
		}
		var in SayHelloReq
		c.Bind(&in)
		return c.String(http.StatusOK, in.Name + "\n")
	})

	s := http.Server{Addr: ":8082", Handler: e}
	if err := s.ListenAndServe(); err != http.ErrServerClosed {
		log.Fatal(err)
	}
}

Output:

x@x:~/$ curl -v -X POST  http://localhost:8082/post -d 'name=Joe'
Note: Unnecessary use of -X or --request, POST is already inferred.
*   Trying 127.0.0.1:8082...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 8082 (#0)
> POST /post HTTP/1.1
> Host: localhost:8082
> User-Agent: curl/7.68.0
> Accept: */*
> Content-Length: 8
> Content-Type: application/x-www-form-urlencoded
> 
* upload completely sent off: 8 out of 8 bytes
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Content-Type: text/plain; charset=UTF-8
< Date: Fri, 16 Jul 2021 03:18:01 GMT
< Content-Length: 4
< 
Joe
* Connection #0 to host localhost left intact

[DenisYin66]

oh,thanks.i can got it. but I mean the sturct is generated automatically by protoc. Is there a better solution without adding form tag? If not, I will add a service to add form tag.

[aldas]

You could write sed awk etc command that does replacement/insertion for those protoc generated files and is executed after protoc call.