gin/binding/binding.go
Suhas Karanth 6d913fc343 fix(binding): Expose validator engine used by the default Validator (#1277)
* fix(binding): Expose validator engine used by the default Validator

- Add func ValidatorEngine for returning the underlying validator engine used
  in the default StructValidator implementation.
- Remove the function RegisterValidation from the StructValidator interface
  which made it immpossible to use a StructValidator implementation without the
  validator.v8 library.
- Update and rename test for registering validation
  Test{RegisterValidation => ValidatorEngine}.
- Update readme and example for registering custom validation.
- Add example for registering struct level validation.
- Add documentation for the following binding funcs/types:
  - Binding interface
  - StructValidator interface
  - Validator instance
  - Binding implementations
  - Default func

* fix(binding): Move validator engine getter inside interface

* docs: rm date cmd from custom validation demo
2018-03-29 14:33:07 +08:00

94 lines
3.0 KiB
Go

// Copyright 2014 Manu Martinez-Almeida. All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.
package binding
import (
"net/http"
)
const (
MIMEJSON = "application/json"
MIMEHTML = "text/html"
MIMEXML = "application/xml"
MIMEXML2 = "text/xml"
MIMEPlain = "text/plain"
MIMEPOSTForm = "application/x-www-form-urlencoded"
MIMEMultipartPOSTForm = "multipart/form-data"
MIMEPROTOBUF = "application/x-protobuf"
MIMEMSGPACK = "application/x-msgpack"
MIMEMSGPACK2 = "application/msgpack"
)
// Binding describes the interface which needs to be implemented for binding the
// data present in the request such as JSON request body, query parameters or
// the form POST.
type Binding interface {
Name() string
Bind(*http.Request, interface{}) error
}
// StructValidator is the minimal interface which needs to be implemented in
// order for it to be used as the validator engine for ensuring the correctness
// of the reqest. Gin provides a default implementation for this using
// https://github.com/go-playground/validator/tree/v8.18.2.
type StructValidator interface {
// ValidateStruct can receive any kind of type and it should never panic, even if the configuration is not right.
// If the received type is not a struct, any validation should be skipped and nil must be returned.
// If the received type is a struct or pointer to a struct, the validation should be performed.
// If the struct is not valid or the validation itself fails, a descriptive error should be returned.
// Otherwise nil must be returned.
ValidateStruct(interface{}) error
// Engine returns the underlying validator engine which powers the
// StructValidator implementation.
Engine() interface{}
}
// Validator is the default validator which implements the StructValidator
// interface. It uses https://github.com/go-playground/validator/tree/v8.18.2
// under the hood.
var Validator StructValidator = &defaultValidator{}
// These implement the Binding interface and can be used to bind the data
// present in the request to struct instances.
var (
JSON = jsonBinding{}
XML = xmlBinding{}
Form = formBinding{}
Query = queryBinding{}
FormPost = formPostBinding{}
FormMultipart = formMultipartBinding{}
ProtoBuf = protobufBinding{}
MsgPack = msgpackBinding{}
)
// Default returns the appropriate Binding instance based on the HTTP method
// and the content type.
func Default(method, contentType string) Binding {
if method == "GET" {
return Form
}
switch contentType {
case MIMEJSON:
return JSON
case MIMEXML, MIMEXML2:
return XML
case MIMEPROTOBUF:
return ProtoBuf
case MIMEMSGPACK, MIMEMSGPACK2:
return MsgPack
default: //case MIMEPOSTForm, MIMEMultipartPOSTForm:
return Form
}
}
func validate(obj interface{}) error {
if Validator == nil {
return nil
}
return Validator.ValidateStruct(obj)
}