From 010e1942bb6acf62662de50e8889c0f7188a7dff Mon Sep 17 00:00:00 2001
From: tonnyzhang <wodexintiao@gmail.com>
Date: Tue, 28 Sep 2021 15:38:40 +0800
Subject: [PATCH] feat: add method
 ShouldBindWidth/ShouldBindBodyWith/ShouldBindWithJSON/ShouldBindBodyWithJSON;
 close #21

---
 binding/Binding.go | 19 +++++++++++++++++++
 binding/json.go    | 28 ++++++++++++++++++++++++++++
 context_binding.go | 43 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+)
 create mode 100644 binding/Binding.go
 create mode 100644 binding/json.go
 create mode 100644 context_binding.go

diff --git a/binding/Binding.go b/binding/Binding.go
new file mode 100644
index 0000000..0f1dad9
--- /dev/null
+++ b/binding/Binding.go
@@ -0,0 +1,19 @@
+package binding
+
+import "net/http"
+
+// IBinding Binding interface
+type IBinding interface {
+	Bind(*http.Request, interface{}) error
+}
+
+// IBindingBody bind body
+type IBindingBody interface {
+	IBinding
+	BindBody([]byte, interface{}) error
+}
+
+var (
+	// JSON json binding
+	JSON = jsonBinding{}
+)
diff --git a/binding/json.go b/binding/json.go
new file mode 100644
index 0000000..f135296
--- /dev/null
+++ b/binding/json.go
@@ -0,0 +1,28 @@
+package binding
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+type jsonBinding struct{}
+
+func (jsonBinding) Bind(req *http.Request, obj interface{}) (err error) {
+	if req == nil || req.Body == nil {
+		err = fmt.Errorf("bad request")
+	} else {
+		err = decodeJSON(req.Body, obj)
+	}
+	return
+}
+func (jsonBinding) BindBody(b []byte, obj interface{}) error {
+	return decodeJSON(bytes.NewBuffer(b), obj)
+}
+
+func decodeJSON(r io.Reader, obj interface{}) error {
+	decoder := json.NewDecoder(r)
+	return decoder.Decode(obj)
+}
diff --git a/context_binding.go b/context_binding.go
new file mode 100644
index 0000000..1664704
--- /dev/null
+++ b/context_binding.go
@@ -0,0 +1,43 @@
+package cotton
+
+import (
+	"io/ioutil"
+
+	"github.com/tonny-zhang/cotton/binding"
+)
+
+// ShouldBindWith bind
+func (ctx *Context) ShouldBindWith(obj interface{}, b binding.IBinding) error {
+	return b.Bind(ctx.Request, obj)
+}
+
+// BodyBytesKey indicates a default body bytes key.
+const BodyBytesKey = "cotton/bbk"
+
+// ShouldBindBodyWith bind body
+func (ctx *Context) ShouldBindBodyWith(obj interface{}, bb binding.IBindingBody) (err error) {
+	var body []byte
+	if v, ok := ctx.Get(BodyBytesKey); ok {
+		if vv, ok := v.([]byte); ok {
+			body = vv
+		}
+	}
+	if body == nil {
+		body, err = ioutil.ReadAll(ctx.Request.Body)
+		if err != nil {
+			return
+		}
+		ctx.Set(BodyBytesKey, body)
+	}
+	return bb.BindBody(body, obj)
+}
+
+// ShouldBindWithJSON bind with json
+func (ctx *Context) ShouldBindWithJSON(obj interface{}) error {
+	return ctx.ShouldBindWith(obj, binding.JSON)
+}
+
+// ShouldBindBodyWithJSON bind body with json
+func (ctx *Context) ShouldBindBodyWithJSON(obj interface{}) (err error) {
+	return ctx.ShouldBindBodyWith(obj, binding.JSON)
+}