example: write our own customized router using the high-level API which gives access to the correct context and routes

Former-commit-id: d2369c20490619cad0dd6f7b6ed01cdbef51a853

_examples/README.md

@@ -146,8 +146,11 @@ Navigate through examples for a better understanding.
 - [Custom HTTP Errors](routing/http-errors/main.go)
 - [Dynamic Path](routing/dynamic-path/main.go)
     * [root level wildcard path](routing/dynamic-path/root-wildcard/main.go)
+- [Write your own custom parameter types](routing/macros/main.go) **NEW**
 - [Reverse routing](routing/reverse/main.go)
-- [Custom wrapper](routing/custom-wrapper/main.go)
+- [Custom Router (high-level)](routing/custom-high-level-router/main.go) **NEW**
+- [Custom Router (low-level)](routing/custom-low-level-router/main.go) **NEW**
+- [Custom Wrapper](routing/custom-wrapper/main.go)
 - Custom Context
     * [method overriding](routing/custom-context/method-overriding/main.go)
     * [new implementation](routing/custom-context/new-implementation/main.go)

_examples/README_ZH.md

@@ -105,7 +105,10 @@ app.Get("{root:path}", rootWildcardHandler)
 - [自定义 HTTP 错误](routing/http-errors/main.go)
 - [动态路径](routing/dynamic-path/main.go)
     * [根级通配符路径](routing/dynamic-path/root-wildcard/main.go)
+- [Write your own custom parameter types](routing/macros/main.go) **NEW**
 - [反向路由](routing/reverse/main.go)
+- [Custom Router (high-level)](routing/custom-high-level-router/main.go) **NEW**
+- [Custom Router (low-level)](routing/custom-low-level-router/main.go) **NEW**
 - [自定义包装](routing/custom-wrapper/main.go)
 - 自定义上下文
     * [方法重写](routing/custom-context/method-overriding/main.go)

_examples/routing/custom-high-level-router/main.go

@@ -0,0 +1,103 @@
+package main
+
+import (
+	"strings"
+
+	"github.com/kataras/iris"
+	"github.com/kataras/iris/context"
+	"github.com/kataras/iris/core/router"
+)
+
+/* A Router should contain all three of the following methods:
+   - HandleRequest should handle the request based on the Context.
+	  HandleRequest(ctx context.Context)
+   - Build should builds the handler, it's being called on router's BuildRouter.
+	  Build(provider router.RoutesProvider) error
+   - RouteExists reports whether a particular route exists.
+      RouteExists(ctx context.Context, method, path string) bool
+
+For a more detailed, complete and useful example
+you can take a look at the iris' router itself which is located at:
+https://github.com/kataras/iris/tree/master/core/router/handler.go
+which completes this exact interface, the `router#RequestHandler`.
+*/
+type customRouter struct {
+	// a copy of routes (safer because you will not be able to alter a route on serve-time without a `app.RefreshRouter` call):
+	// []router.Route
+	// or just expect the whole routes provider:
+	provider router.RoutesProvider
+}
+
+// HandleRequest a silly example which finds routes based only on the first part of the requested path
+// which must be a static one as well, the rest goes to fill the parameters.
+func (r *customRouter) HandleRequest(ctx context.Context) {
+	path := ctx.Path()
+	ctx.Application().Logger().Infof("Requested resource path: %s", path)
+
+	parts := strings.Split(path, "/")[1:]
+	staticPath := "/" + parts[0]
+	for _, route := range r.provider.GetRoutes() {
+		if strings.HasPrefix(route.Path, staticPath) {
+			paramParts := parts[1:]
+			for _, paramValue := range paramParts {
+				for _, p := range route.Tmpl().Params {
+					ctx.Params().Set(p.Name, paramValue)
+				}
+			}
+
+			ctx.SetCurrentRouteName(route.Name)
+			ctx.Do(route.Handlers)
+			return
+		}
+	}
+
+	// if nothing found...
+	ctx.StatusCode(iris.StatusNotFound)
+}
+
+func (r *customRouter) Build(provider router.RoutesProvider) error {
+	for _, route := range provider.GetRoutes() {
+		// do any necessary validation or conversations based on your custom logic here
+		// but always run the "BuildHandlers" for each registered route.
+		route.BuildHandlers()
+		// [...] r.routes = append(r.routes, *route)
+	}
+
+	r.provider = provider
+	return nil
+}
+
+func (r *customRouter) RouteExists(ctx context.Context, method, path string) bool {
+	// [...]
+	return false
+}
+
+func main() {
+	app := iris.New()
+
+	// In case you are wondering, the parameter types and macros like "{param:string $func()}" still work inside
+	// your custom router if you fetch by the Route's Handler
+	// because they are middlewares under the hood, so you don't have to implement the logic of handling them manually,
+	// though you have to match what requested path is what route and fill the ctx.Params(), this is the work of your custom router.
+	app.Get("/hello/{name}", func(ctx context.Context) {
+		name := ctx.Params().Get("name")
+		ctx.Writef("Hello %s\n", name)
+	})
+
+	app.Get("/cs/{num:uint64 min(10) else 400}", func(ctx context.Context) {
+		num := ctx.Params().GetUint64Default("num", 0)
+		ctx.Writef("num is: %d\n", num)
+	})
+
+	// To replace the existing router with a customized one by using the iris/context.Context
+	// you have to use the `app.BuildRouter` method before `app.Run` and after the routes registered.
+	// You should pass your custom router's instance as the second input arg, which must completes the `router#RequestHandler`
+	// interface as shown above.
+	//
+	// To see how you can build something even more low-level without direct iris' context support (you can do that manually as well)
+	// navigate to the "custom-wrapper" example instead.
+	myCustomRouter := new(customRouter)
+	app.BuildRouter(app.ContextPool, myCustomRouter, app.APIBuilder, true)
+
+	app.Run(iris.Addr(":8080"), iris.WithoutServerError(iris.ErrServerClosed))
+}

_examples/routing/custom-low-level-router/main.go

@@ -0,0 +1,6 @@
+/// TODO: showcase the `app.Downgrade` feature tomorrow if not already existing elsewhere.
+package main
+
+func main() {
+	panic("TODO")
+}