rewrite middleware: add a feature which supports users.json to users?format=json local route redirection

HISTORY.md

@@ -365,14 +365,30 @@ Other Improvements:
 - New [Rewrite Engine Middleware](https://github.com/kataras/iris/tree/master/middleware/rewrite). Set up redirection rules for path patterns using the syntax we all know. [Example Code](https://github.com/kataras/iris/tree/master/_examples/routing/rewrite).
 
 ```yml
-# REDIRECT_CODE PATH_PATTERN TARGET_PATH_REPL
-RedirectMatch:
-    # redirects /seo/* to /*
+RedirectMatch: # REDIRECT_CODE_DIGITS | PATTERN_REGEX | TARGET_REPL
+  # Redirects /seo/* to /*
   - 301 /seo/(.*) /$1
-    # redirects /docs/v12* to /docs
+
+  # Redirects /docs/v12* to /docs
   - 301 /docs/v12(.*) /docs
-    # redirects /old(.*) to /
+
+  # Redirects /old(.*) to /
   - 301 /old(.*) /
+
+  # Redirects http or https://test.* to http or https://newtest.*
+  - 301 ^(http|https)://test.(.*) $1://newtest.$2
+
+  # Handles /*.json or .xml as *?format=json or xml,
+  # without redirect. See /users route.
+  # When Code is 0 then it does not redirect the request,
+  # instead it changes the request URL
+  # and leaves a route handle the request.
+  - 0 /(.*).(json|xml) /$1?format=$2
+
+# Redirects root domain to www.
+# Creation of a www subdomain inside the Application is unnecessary,
+# all requests are handled by the root Application itself.
+PrimarySubdomain: www
 ```
 
 - New `TraceRoute bool` on [middleware/logger](https://github.com/kataras/iris/tree/master/middleware/logger) middleware. Displays information about the executed route. Also marks the handlers executed. Screenshot:

_examples/routing/rewrite/main.go

@@ -7,9 +7,11 @@ import (
 
 func main() {
 	app := iris.New()
+
 	app.Get("/", index)
 	app.Get("/about", about)
 	app.Get("/docs", docs)
+	app.Get("/users", listUsers)
 
 	app.Subdomain("test").Get("/", testIndex)
 
@@ -29,6 +31,7 @@ func main() {
 	// http://localhost:8080/docs/v12some      -> http://localhost:8080/docs
 	// http://localhost:8080/oldsome           -> http://localhost:8080
 	// http://localhost:8080/oldindex/random   -> http://localhost:8080
+	// http://localhost:8080/users.json        -> http://localhost:8080/users?format=json
 	app.Listen(":8080")
 }
 
@@ -44,8 +47,24 @@ func docs(ctx iris.Context) {
 	ctx.WriteString("Docs")
 }
 
+func listUsers(ctx iris.Context) {
+	format := ctx.URLParamDefault("format", "text")
+	/*
+		switch format{
+			case "json":
+				ctx.JSON(response)
+			case "xml":
+				ctx.XML(response)
+			// [...]
+		}
+	*/
+	ctx.Writef("Format: %s", format)
+}
+
 func testIndex(ctx iris.Context) {
-	ctx.WriteString("Test Subdomain Index (This should never be executed, redirects to newtest subdomain)")
+	ctx.WriteString(`Test Subdomain Index
+					(This should never be executed,
+					redirects to newtest subdomain)`)
 }
 
 func newTestIndex(ctx iris.Context) {
@@ -63,6 +82,7 @@ rewriteOptions := rewrite.Options{
 		"301 /docs/v12(.*) /docs",
 		"301 /old(.*) /",
 		"301 ^(http|https)://test.(.*) $1://newtest.$2",
+		"0 /(.*).(json|xml) /$1?format=$2",
 	},
 	PrimarySubdomain: "www",
 }
@@ -77,5 +97,6 @@ app.Use(rewriteEngine.Handler)
 //
 // To make the entire application respect the redirect rules
 // you have to wrap the Iris Router and pass the `Rewrite` method instead
-// as we did at this example.
+// as we did at this example:
+// app.WrapRouter(rewriteEngine.Rewrite)
 */

_examples/routing/rewrite/redirects.yml

@@ -1,12 +1,24 @@
-# REDIRECT_CODE PATH_PATTERN TARGET_PATH_REPL
-RedirectMatch:
-    # redirects /seo/* to /*
+RedirectMatch: # REDIRECT_CODE_DIGITS | PATTERN_REGEX | TARGET_REPL
+  # Redirects /seo/* to /*
   - 301 /seo/(.*) /$1
-    # redirects /docs/v12* to /docs
+
+  # Redirects /docs/v12* to /docs
   - 301 /docs/v12(.*) /docs
-    # redirects /old(.*) to /
+
+  # Redirects /old(.*) to /
   - 301 /old(.*) /
-    # redirects http or https://test.* to http or https://newtest.*
+
+  # Redirects http or https://test.* to http or https://newtest.*
   - 301 ^(http|https)://test.(.*) $1://newtest.$2
-# redirects root domain to www.
+
+  # Handle /*.json or .xml as *?format=json or xml,
+  # without redirect. See /users route.
+  # When Code is 0 then it does not redirect the request,
+  # instead it changes the request URL
+  # and leaves a route handle the request.
+  - 0 /(.*).(json|xml) /$1?format=$2
+
+# Redirects root domain to www.
+# Creation of a www subdomain inside the Application is unnecessary,
+# all requests are handled by the root Application itself.
 PrimarySubdomain: www

context/context.go

@@ -1906,14 +1906,14 @@ func (ctx *Context) AbsoluteURI(s string) string {
 }
 
 // Redirect sends a redirect response to the client
-// to a specific url or relative path.
-// accepts 2 parameters string and an optional int
-// first parameter is the url to redirect
-// second parameter is the http status should send,
-// default is 302 (StatusFound),
-// you can set it to 301 (Permant redirect)
-// or 303 (StatusSeeOther) if POST method,
-// or StatusTemporaryRedirect(307) if that's nessecery.
+// of an absolute or relative target URL.
+// It accepts 2 input arguments, a string and an optional integer.
+// The first parameter is the target url to redirect.
+// The second one is the HTTP status code should be sent
+// among redirection response,
+// If the second parameter is missing, then it defaults to 302 (StatusFound).
+// It can be set to 301 (Permant redirect), StatusTemporaryRedirect(307)
+// or 303 (StatusSeeOther) if POST method.
 func (ctx *Context) Redirect(urlToRedirect string, statusHeader ...int) {
 	ctx.StopExecution()
 	// get the previous status code given by the end-developer.

middleware/rewrite/rewrite.go

@@ -187,6 +187,18 @@ func (e *Engine) Rewrite(w http.ResponseWriter, r *http.Request, routeHandler ht
 				return
 			}
 
+			if rd.noRedirect {
+				u, err := r.URL.Parse(target)
+				if err != nil {
+					http.Error(w, err.Error(), http.StatusMisdirectedRequest)
+					return
+				}
+
+				r.URL = u
+				routeHandler(w, r)
+				return
+			}
+
 			if !rd.isRelativePattern {
 				// this performs better, no need to check query or host,
 				// the uri already built.
@@ -208,6 +220,7 @@ type redirectMatch struct {
 	target  string
 
 	isRelativePattern bool
+	noRedirect        bool
 }
 
 func (r *redirectMatch) matchAndReplace(src string) (string, bool) {
@@ -241,20 +254,16 @@ func parseRedirectMatchLine(s string) (*redirectMatch, error) {
 		return nil, fmt.Errorf("redirect match: status code digits: %s: %v", codeStr, err)
 	}
 
-	if code <= 0 {
-		code = http.StatusMovedPermanently
-	}
-
 	regex := regexp.MustCompile(pattern)
 	if regex.MatchString(target) {
 		return nil, fmt.Errorf("redirect match: loop detected: pattern: %s vs target: %s", pattern, target)
 	}
 
 	v := &redirectMatch{
-		code:    code,
-		pattern: regex,
-		target:  target,
-
+		code:              code,
+		pattern:           regex,
+		target:            target,
+		noRedirect:        code <= 0,
 		isRelativePattern: pattern[0] == '/', // search by path.
 	}