add examples for read using custom decoder per type, read using custom decoder via iris#UnmarshalerFunc and to complete it add an example for the context#ReadXML.

Former-commit-id: 536b1780f12d0b9d9ce9aa976a0f95f18634ec2d

_examples/http_responsewriter/herotemplate/app.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"bytes"
-	"log"
 
 	"github.com/kataras/iris/_examples/http_responsewriter/herotemplate/template"
 
@@ -13,11 +12,15 @@ import (
 // $ go run app.go
 //
 // Read more at https://github.com/shiyanhui/hero/hero
+
 func main() {
 
 	app := iris.New()
 
 	app.Get("/users", func(ctx iris.Context) {
+		ctx.Gzip(true)
+		ctx.ContentType("text/html")
+
 		var userList = []string{
 			"Alice",
 			"Bob",
@@ -25,30 +28,27 @@ func main() {
 		}
 
 		// Had better use buffer sync.Pool.
-		// Hero exports GetBuffer and PutBuffer for this.
+		// Hero(github.com/shiyanhui/hero/hero) exports GetBuffer and PutBuffer for this.
 		//
 		// buffer := hero.GetBuffer()
 		// defer hero.PutBuffer(buffer)
-		buffer := new(bytes.Buffer)
-		template.UserList(userList, buffer)
-
-		if _, err := ctx.Write(buffer.Bytes()); err != nil {
-			log.Printf("ERR: %s\n", err)
-		}
-	})
-
-	app.Get("/users2", func(ctx iris.Context) {
-		var userList = []string{
-			"Alice",
-			"Bob",
-			"Tom",
-		}
+		// buffer := new(bytes.Buffer)
+		// template.UserList(userList, buffer)
+		// ctx.Write(buffer.Bytes())
 
 		// using an io.Writer for automatic buffer management (i.e. hero built-in buffer pool),
 		// iris context implements the io.Writer by its ResponseWriter
 		// which is an enhanced version of the standard http.ResponseWriter
-		// but still 100% compatible.
-		template.UserListToWriter(userList, ctx)
+		// but still 100% compatible, GzipResponseWriter too:
+		// _, err := template.UserListToWriter(userList, ctx.GzipResponseWriter())
+		buffer := new(bytes.Buffer)
+		template.UserList(userList, buffer)
+
+		_, err := ctx.Write(buffer.Bytes())
+		if err != nil {
+			ctx.StatusCode(iris.StatusInternalServerError)
+			ctx.WriteString(err.Error())
+		}
 	})
 
 	app.Run(iris.Addr(":8080"))