added URL helper methods and godoc update

Author: jeevatkm

essentials.go

@@ -0,0 +1,11 @@
+// Copyright (c) Jeevanandam M. (https://github.com/jeevatkm)
+// aahframework.org/essentials source code and usage is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package ess
+
+// Valuer interface is general purpose to `Set` and `Get` operations.
+type Valuer interface {
+	Get(key string) interface{}
+	Set(key string, value interface{})
+}

guid.go

@@ -77,6 +77,8 @@ func readRandomUint32() uint32 {
 		return (uint32(b[0]) << 0) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24)
 	}
 
+	// To initialize package unexported variable 'guidCounter'.
+	// This panic would happen at program startup, so no worries at runtime panic.
 	panic(errors.New("ess - guid: unable to generate random object id"))
 }
 
@@ -97,6 +99,7 @@ func readMachineID() []byte {
 		return id
 	}
 
-	// return nil, errors.New("guid: unable to get hostname and random bytes")
+	// To initialize package unexported variable 'machineID'.
+	// This panic would happen at program startup, so no worries at runtime panic.
 	panic(errors.New("ess - guid: unable to get hostname and random bytes"))
 }

url.go

@@ -0,0 +1,28 @@
+// Copyright (c) Jeevanandam M. (https://github.com/jeevatkm)
+// aahframework.org/essentials source code and usage is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package ess
+
+import "net/url"
+
+// IsVaildURL method returns true if given raw URL gets parsed without any errors
+// otherwise false.
+func IsVaildURL(rawurl string) bool {
+	_, err := url.Parse(rawurl)
+	return err == nil
+}
+
+// IsRelativeURL method returns true if given raw URL is relative URL otherwise false.
+func IsRelativeURL(rawurl string) bool {
+	return !IsAbsURL(rawurl)
+}
+
+// IsAbsURL method returns true if given raw URL is absolute URL otherwise false.
+func IsAbsURL(rawurl string) bool {
+	u, err := url.Parse(rawurl)
+	if err != nil {
+		return false
+	}
+	return u.IsAbs()
+}

url_test.go

@@ -0,0 +1,54 @@
+// Copyright (c) Jeevanandam M. (https://github.com/jeevatkm)
+// aahframework.org/essentials source code and usage is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package ess
+
+import (
+	"testing"
+
+	"aahframework.org/test.v0/assert"
+)
+
+func TestURLValue(t *testing.T) {
+	t.Log("Valid URLs")
+	for _, u := range []string{
+		"https://aahframework.org",
+		"/facebook-auth/callback?code=AQD5-i29_Vn7fNg8VgcV-Uzk_QNO1sx6yO-tJvkRiFaGs1n-wnCxUnvLX0V2q25Tx7JRZAiTds2-DIKrDb8jPEdGquMCedQ_mpMZQxsHmPYeg_cP1Xjy2jHooK-1ZDJZQHXtDSL8FA7r3nVA7WcrCuLZrlrgXq8LnOSAil3oMD-RqPix-nI576GvAPGgiXo6ep_AfS2GaF8A8TOTwl2iwEjB74F23yEukNpz5tmDJVfH02qtrGECuDfaAEPc-4u2wVIIWKCWy3oEEeoEr4zBdzsMtUR1FP3X5yUm0_yAYFP3taAPrpM-5UqtJWmUgaOY-U0&state=72du0BBFIPjW4PsWcI21SccfRX-EkojC4dZ49MYJZac",
+		"https://www.facebook.com/dialog/oauth?client_id=182958108394860&redirect_uri=http%3A%2F%2Flocalhost%3A8080%2Ffacebook-auth%2Fcallback&response_type=code&scope=public_profile+email&state=72du0BBFIPjW4PsWcI21SccfRX-EkojC4dZ49MYJZac",
+		"https://godoc.org/golang.org/x/oauth2",
+		"http://godoc.org/",
+	} {
+		assert.True(t, IsVaildURL(u))
+	}
+
+	t.Log("Absolute URL")
+	for _, u := range []string{
+		"https://aahframework.org",
+		"https://www.facebook.com/dialog/oauth?client_id=182958108394860&redirect_uri=http%3A%2F%2Flocalhost%3A8080%2Ffacebook-auth%2Fcallback&response_type=code&scope=public_profile+email&state=72du0BBFIPjW4PsWcI21SccfRX-EkojC4dZ49MYJZac",
+		"https://godoc.org/golang.org/x/oauth2",
+		"http://godoc.org/",
+	} {
+		assert.True(t, IsAbsURL(u))
+	}
+
+	t.Log("Error - Absolute URL")
+	for _, u := range []string{
+		"://aahframework.org",
+		"://",
+		"http",
+		"https",
+	} {
+		assert.False(t, IsAbsURL(u))
+	}
+
+	t.Log("Relative URL")
+	for _, u := range []string{
+		"/facebook-auth/callback?code=AQD5-i29_Vn7fNg8VgcV-Uzk_QNO1sx6yO-tJvkRiFaGs1n-wnCxUnvLX0V2q25Tx7JRZAiTds2-DIKrDb8jPEdGquMCedQ_mpMZQxsHmPYeg_cP1Xjy2jHooK-1ZDJZQHXtDSL8FA7r3nVA7WcrCuLZrlrgXq8LnOSAil3oMD-RqPix-nI576GvAPGgiXo6ep_AfS2GaF8A8TOTwl2iwEjB74F23yEukNpz5tmDJVfH02qtrGECuDfaAEPc-4u2wVIIWKCWy3oEEeoEr4zBdzsMtUR1FP3X5yUm0_yAYFP3taAPrpM-5UqtJWmUgaOY-U0&state=72du0BBFIPjW4PsWcI21SccfRX-EkojC4dZ49MYJZac",
+		"/dialog/oauth?client_id=182958108394860&redirect_uri=http%3A%2F%2Flocalhost%3A8080%2Ffacebook-auth%2Fcallback&response_type=code&scope=public_profile+email&state=72du0BBFIPjW4PsWcI21SccfRX-EkojC4dZ49MYJZac",
+		"/golang.org/x/oauth2",
+	} {
+		assert.True(t, IsRelativeURL(u))
+	}
+
+}