add 'Configuration.PathIntelligence' and 'OnErrorCode' and 'OnAnyErrorCode' on APIContainer

Former-commit-id: bc3d0232106622063205f326bfa4ed3aa84179de

_examples/routing/intelligence/manual/main.go

@@ -0,0 +1,37 @@
+package main
+
+import "github.com/kataras/iris/v12"
+
+func main() {
+	app := iris.New()
+	app.OnErrorCode(iris.StatusNotFound, notFound)
+
+	// [register some routes...]
+	app.Get("/home", handler)
+	app.Get("/news", handler)
+	app.Get("/news/politics", handler)
+	app.Get("/user/profile", handler)
+	app.Get("/user", handler)
+	app.Get("/newspaper", handler)
+	app.Get("/user/{id}", handler)
+
+	app.Listen(":8080")
+}
+
+func notFound(ctx iris.Context) {
+	suggestPaths := ctx.FindClosest(3)
+	if len(suggestPaths) == 0 {
+		ctx.WriteString("404 not found")
+		return
+	}
+
+	ctx.HTML("Did you mean?<ul>")
+	for _, s := range suggestPaths {
+		ctx.HTML(`<li><a href="%s">%s</a></li>`, s, s)
+	}
+	ctx.HTML("</ul>")
+}
+
+func handler(ctx iris.Context) {
+	ctx.Writef("Path: %s", ctx.Path())
+}