Add some _examples in the main repository too.

Former-commit-id: 98895c34115ec2076b431332f0ffe9645adf7590

_examples/examples/url-shortener/main.go

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+package main
+
+import (
+	"html/template"
+	"math/rand"
+	"net/url"
+	"sync"
+	"time"
+
+	"gopkg.in/kataras/iris.v6"
+	"gopkg.in/kataras/iris.v6/adaptors/httprouter"
+	"gopkg.in/kataras/iris.v6/adaptors/view"
+)
+
+func main() {
+	app := iris.New()
+	app.Adapt(
+		iris.DevLogger(),
+		httprouter.New(),
+		view.HTML("./templates", ".html").Reload(true),
+	)
+
+	// Serve static files (css)
+	app.StaticWeb("/static", "./static_files")
+
+	var mu sync.Mutex
+	var urls = map[string]string{
+		"iris": "http://support.iris-go.com",
+	}
+
+	app.Get("/", func(ctx *iris.Context) {
+		ctx.Render("index.html", iris.Map{"url_count": len(urls)})
+	})
+
+	// find and execute a short url by its key
+	// used on http://localhost:8080/url/dsaoj41u321dsa
+	execShortURL := func(ctx *iris.Context, key string) {
+		if key == "" {
+			ctx.EmitError(iris.StatusBadRequest)
+			return
+		}
+
+		value, found := urls[key]
+		if !found {
+			ctx.SetStatusCode(iris.StatusNotFound)
+			ctx.Writef("Short URL for key: '%s' not found", key)
+			return
+		}
+
+		ctx.Redirect(value, iris.StatusTemporaryRedirect)
+	}
+	app.Get("/url/:shortkey", func(ctx *iris.Context) {
+		execShortURL(ctx, ctx.Param("shortkey"))
+	})
+
+	//  for wildcard subdomain (yeah.. cool) http://dsaoj41u321dsa.localhost:8080
+	// Note:
+	// if you want subdomains (chrome doesn't works on localhost, so you have to define other hostname on app.Listen)
+	// app.Party("*.", func(ctx *iris.Context) {
+	// 	execShortURL(ctx, ctx.Subdomain())
+	// })
+
+	app.Post("/url/shorten", func(ctx *iris.Context) {
+		data := make(map[string]interface{}, 0)
+		data["url_count"] = len(urls)
+		value := ctx.FormValue("url")
+		if value == "" {
+			data["form_result"] = "You need to a enter a URL."
+		} else {
+			urlValue, err := url.ParseRequestURI(value)
+			if err != nil {
+				// ctx.JSON(iris.StatusInternalServerError,
+				// 	iris.Map{"status": iris.StatusInternalServerError,
+				// 		"error":  err.Error(),
+				// 		"reason": "Invalid URL",
+				// 	})
+				data["form_result"] = "Invalid URL."
+			} else {
+				key := randomString(12)
+				// Make sure that the key is unique
+				for {
+					if _, exists := urls[key]; !exists {
+						break
+					}
+					key = randomString(8)
+				}
+				mu.Lock()
+				urls[key] = urlValue.String()
+				mu.Unlock()
+				ctx.SetStatusCode(iris.StatusOK)
+				shortenURL := "http://" + app.Config.VHost + "/url/" + key
+				data["form_result"] = template.HTML("<pre>Here is your short URL: <a href='" + shortenURL + "'>" + shortenURL + " </a></pre>")
+			}
+
+		}
+		ctx.Render("index.html", data)
+	})
+
+	app.Listen("localhost:8080")
+}
+
+//  +------------------------------------------------------------+
+//  |                                                            |
+//  |                      Random String                         |
+//  |                                                            |
+//  +------------------------------------------------------------+
+
+const (
+	letterBytes   = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	letterIdxBits = 6                    // 6 bits to represent a letter index
+	letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
+	letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
+)
+
+func randomString(n int) string {
+	src := rand.NewSource(time.Now().UnixNano())
+	b := make([]byte, n)
+	// A src.Int63() generates 63 random bits, enough for letterIdxMax characters!
+	for i, cache, remain := n-1, src.Int63(), letterIdxMax; i >= 0; {
+		if remain == 0 {
+			cache, remain = src.Int63(), letterIdxMax
+		}
+		if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
+			b[i] = letterBytes[idx]
+			i--
+		}
+		cache >>= letterIdxBits
+		remain--
+	}
+
+	return string(b)
+}

_examples/examples/url-shortener/static_files/style.css

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+body{
+    background-color:silver;
+}

_examples/examples/url-shortener/templates/index.html

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+<html>
+
+<head>
+    <meta charset="utf-8">
+    <title>Golang URL Shortener</title>
+    <link rel="stylesheet" href="/static/css/style.css" />
+</head>
+
+<body>
+    <h2>Golang URL Shortener</h2>
+    <h3>{{ .form_result}}</h3>
+    <form action="/url/shorten" method="POST">
+        <input type="text" name="url" style="width: 35em;" />
+        <input type="submit" value="Shorten!" />
+    </form>
+
+    <p>{{ .url_count }} URLs shortened</p>
+</body>
+
+</html>