Add example for struct validation(3rd-party) through json request body binding

Former-commit-id: 78bbbe068f219e5a264951c900b77cb9b70f2079

_examples/http_request/upload-files/main.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"io"
 	"mime/multipart"
+	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
@@ -44,10 +46,53 @@ func main() {
 		ctx.UploadFormFiles("./uploads", beforeSave)
 	})
 
+	app.Post("/upload_manual", func(ctx iris.Context) {
+		// Get the max post value size passed via iris.WithPostMaxMemory.
+		maxSize := ctx.Application().ConfigurationReadOnly().GetPostMaxMemory()
+
+		err := ctx.Request().ParseMultipartForm(maxSize)
+		if err != nil {
+			ctx.StatusCode(iris.StatusInternalServerError)
+			ctx.WriteString(err.Error())
+			return
+		}
+
+		form := ctx.Request().MultipartForm
+
+		files := form.File["files[]"]
+		failures := 0
+		for _, file := range files {
+			_, err = saveUploadedFile(file, "./uploads")
+			if err != nil {
+				failures++
+				ctx.Writef("failed to upload: %s\n", file.Filename)
+			}
+		}
+		ctx.Writef("%d files uploaded", len(files)-failures)
+	})
+
 	// start the server at http://localhost:8080 with post limit at 32 MB.
 	app.Run(iris.Addr(":8080"), iris.WithPostMaxMemory(32<<20))
 }
 
+func saveUploadedFile(fh *multipart.FileHeader, destDirectory string) (int64, error) {
+	src, err := fh.Open()
+	if err != nil {
+		return 0, err
+	}
+	defer src.Close()
+
+	out, err := os.OpenFile(filepath.Join(destDirectory, fh.Filename),
+		os.O_WRONLY|os.O_CREATE, os.FileMode(0666))
+
+	if err != nil {
+		return 0, err
+	}
+	defer out.Close()
+
+	return io.Copy(out, src)
+}
+
 func beforeSave(ctx iris.Context, file *multipart.FileHeader) {
 	ip := ctx.RemoteAddr()
 	// make sure you format the ip in a way