create the new FileServer and HandleDir, deprecate the rest APIBuilder/Party static methods and more

relative: https://github.com/kataras/iris/issues/1283 and removing pongo2 from vendor: https://github.com/kataras/iris/issues/1284

Former-commit-id: 3ec57b349f99faca2b8e36d9f7252db0b6ea080d

_examples/http_request/request-logger/request-logger-file-json/main.go

@@ -2,19 +2,56 @@ package main
 
 import (
 	"fmt"
+	"io"
 	"os"
-	"runtime"
 	"strings"
 	"time"
 
 	"github.com/kataras/iris"
 	"github.com/kataras/iris/middleware/logger"
-
-	"github.com/kataras/golog"
 )
 
 const deleteFileOnExit = false
 
+func newRequestLogger(newWriter io.Writer) iris.Handler {
+	c := logger.Config{}
+
+	//	we don't want to use the logger
+	// to log requests to assets and etc
+	c.AddSkipper(func(ctx iris.Context) bool {
+		path := ctx.Path()
+		for _, ext := range excludeExtensions {
+			if strings.HasSuffix(path, ext) {
+				return true
+			}
+		}
+		return false
+	})
+
+	c.LogFuncCtx = func(ctx iris.Context, latency time.Duration) {
+		datetime := time.Now().Format(ctx.Application().ConfigurationReadOnly().GetTimeFormat())
+		customHandlerMessage := ctx.Values().GetString("log_message")
+
+		file, line := ctx.HandlerFileLine()
+		source := fmt.Sprintf("%s:%d", file, line)
+
+		// this will just append a line without an array of javascript objects, readers of this file should read one line per log javascript object,
+		// however, you can improve it even more, this is just a simple example on how to use the `LogFuncCtx`.
+		jsonStr := fmt.Sprintf(`{"datetime":"%s","level":"%s","source":"%s","latency": "%s","status": %d,"method":"%s","path":"%s","message":"%s"}`,
+			datetime, "INFO", source, latency.String(), ctx.GetStatusCode(), ctx.Method(), ctx.Path(), customHandlerMessage)
+
+		fmt.Fprintln(newWriter, jsonStr)
+	}
+
+	return logger.New(c)
+}
+
+func h(ctx iris.Context) {
+	ctx.Values().Set("log_message", "something to give more info to the request logger")
+
+	ctx.Writef("Hello from %s", ctx.Path())
+}
+
 func main() {
 	app := iris.New()
 
@@ -26,56 +63,21 @@ func main() {
 		}
 	}()
 
-	// Handle the logs by yourself using the `app.Logger#Handle` method.
-	// Return true if that handled, otherwise will print to the screen.
-	// You can also use the `app.Logger#SetOutput/AddOutput` to change or add
-	// multi (io.Writer) outputs if you just want to print the message
-	// somewhere else than the terminal screen.
-	app.Logger().Handle(func(l *golog.Log) bool {
-		_, fn, line, _ := runtime.Caller(5)
-
-		var (
-			// formatted date string based on the `golog#TimeFormat`, which can be customized.
-			// Or use the golog.Log#Time field to get the exact time.Time instance.
-			datetime = l.FormatTime()
-			// the log's message level.
-			level = golog.GetTextForLevel(l.Level, false)
-			// the log's message.
-			message = l.Message
-			// the source code line of where it is called,
-			// this can differ on your app, see runtime.Caller(%d).
-			source = fmt.Sprintf("%s#%d", fn, line)
-		)
-
-		// You can always use a custom json structure and json.Marshal and logFile.Write(its result)
-		// but it is faster to just build your JSON string by yourself as we do below.
-		jsonStr := fmt.Sprintf(`{"datetime":"%s","level":"%s","message":"%s","source":"%s"}`, datetime, level, message, source)
-		fmt.Fprintln(logFile, jsonStr)
-
-		/* Example output:
-		{"datetime":"2018/10/31 13:13","level":"[INFO]","message":"My server started","source":"c:/mygopath/src/github.com/kataras/iris/_examples/http_request/request-logger/request-logger-file-json/main.go#71"}
-		*/
-		return true
-	})
-
-	r := newRequestLogger()
+	r := newRequestLogger(logFile)
 
 	app.Use(r)
 	app.OnAnyErrorCode(r, func(ctx iris.Context) {
 		ctx.HTML("<h1> Error: Please try <a href ='/'> this </a> instead.</h1>")
 	})
 
-	h := func(ctx iris.Context) {
-		ctx.Writef("Hello from %s", ctx.Path())
-	}
-
 	app.Get("/", h)
 
 	app.Get("/1", h)
 
 	app.Get("/2", h)
 
-	app.Logger().Info("My server started")
+	app.Get("/", h)
+
 	// http://localhost:8080
 	// http://localhost:8080/1
 	// http://localhost:8080/2
@@ -92,29 +94,6 @@ var excludeExtensions = [...]string{
 	".svg",
 }
 
-func newRequestLogger() iris.Handler {
-	c := logger.Config{
-		Status: true,
-		IP:     true,
-		Method: true,
-		Path:   true,
-	}
-
-	//	we don't want to use the logger
-	// to log requests to assets and etc
-	c.AddSkipper(func(ctx iris.Context) bool {
-		path := ctx.Path()
-		for _, ext := range excludeExtensions {
-			if strings.HasSuffix(path, ext) {
-				return true
-			}
-		}
-		return false
-	})
-
-	return logger.New(c)
-}
-
 // get a filename based on the date, file logs works that way the most times
 // but these are just a sugar.
 func todayFilename() string {