add read-body example

Former-commit-id: 7d7afa555e66fbe7edfa31203c26b4b550f336f4

_examples/http_request/read-body/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"github.com/kataras/iris/v12"
+)
+
+func main() {
+	app := newApp()
+	// See main_test.go for usage.
+	app.Listen(":8080")
+}
+
+func newApp() *iris.Application {
+	app := iris.New()
+	app.Use(setAllowedResponses)
+
+	app.Post("/", readBody)
+
+	return app
+}
+
+func setAllowedResponses(ctx iris.Context) {
+	// Indicate that the Server can send JSON, XML, YAML and MessagePack for this request.
+	ctx.Negotiation().JSON().XML().YAML().MsgPack()
+	// Add more, allowed by the server format of responses, mime types here...
+
+	// If client is missing an "Accept: " header then default it to JSON.
+	ctx.Negotiation().Accept.JSON()
+
+	ctx.Next()
+}
+
+type payload struct {
+	Message string `json:"message" xml:"message" msgpack:"message" yaml:"Message" url:"message" form:"message"`
+}
+
+func readBody(ctx iris.Context) {
+	var p payload
+
+	// Bind request body to "p" depending on the content-type that client sends the data,
+	// e.g. JSON, XML, YAML, MessagePack, Form, URL Query.
+	err := ctx.ReadBody(&p)
+	if err != nil {
+		ctx.StopWithProblem(iris.StatusBadRequest,
+			iris.NewProblem().Title("Parser issue").Detail(err.Error()))
+		return
+	}
+
+	// For the shake of the example, log the received payload.
+	ctx.Application().Logger().Infof("Received: %#+v", p)
+
+	// Send back the payload depending on the accept content type and accept-encoding of the client,
+	// e.g. JSON, XML and so on.
+	ctx.Negotiate(p)
+}