Merge pull request #8 from kikimor/http_custom

External httpClient support

Device.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"net/url"
 	"reflect"
 	"strconv"
 	"strings"
@@ -63,8 +64,8 @@ func (devType DeviceType) String() string {
 	}
 }
 
-//deviceInfo struct contains general information about ONVIF device
-type deviceInfo struct {
+//DeviceInfo struct contains general information about ONVIF device
+type DeviceInfo struct {
 	Manufacturer    string
 	Model           string
 	FirmwareVersion string
@@ -72,15 +73,20 @@ type deviceInfo struct {
 	HardwareId      string
 }
 
-//Device for a new device of onvif and deviceInfo
+//Device for a new device of onvif and DeviceInfo
 //struct represents an abstract ONVIF device.
 //It contains methods, which helps to communicate with ONVIF device
 type Device struct {
-	xaddr     string
-	login     string
-	password  string
+	params    DeviceParams
 	endpoints map[string]string
-	info      deviceInfo
+	info      DeviceInfo
+}
+
+type DeviceParams struct {
+	Xaddr      string
+	Username   string
+	Password   string
+	HttpClient *http.Client
 }
 
 //GetServices return available endpoints
@@ -88,6 +94,11 @@ func (dev *Device) GetServices() map[string]string {
 	return dev.endpoints
 }
 
+//GetServices return available endpoints
+func (dev *Device) GetDeviceInfo() DeviceInfo {
+	return dev.info
+}
+
 func readResponse(resp *http.Response) string {
 	b, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
@@ -103,52 +114,47 @@ func GetAvailableDevicesAtSpecificEthernetInterface(interfaceName string) []Devi
 	*/
 	devices := wsdiscovery.SendProbe(interfaceName, nil, []string{"dn:" + NVT.String()}, map[string]string{"dn": "http://www.onvif.org/ver10/network/wsdl"})
 	nvtDevices := make([]Device, 0)
-	////fmt.Println(devices)
+
 	for _, j := range devices {
 		doc := etree.NewDocument()
 		if err := doc.ReadFromString(j); err != nil {
 			fmt.Errorf("%s", err.Error())
 			return nil
 		}
-		////fmt.Println(j)
+
 		endpoints := doc.Root().FindElements("./Body/ProbeMatches/ProbeMatch/XAddrs")
 		for _, xaddr := range endpoints {
-			//fmt.Println(xaddr.Tag,strings.Split(strings.Split(xaddr.Text(), " ")[0], "/")[2] )
 			xaddr := strings.Split(strings.Split(xaddr.Text(), " ")[0], "/")[2]
 			fmt.Println(xaddr)
 			c := 0
+
 			for c = 0; c < len(nvtDevices); c++ {
-				if nvtDevices[c].xaddr == xaddr {
-					fmt.Println(nvtDevices[c].xaddr, "==", xaddr)
+				if nvtDevices[c].params.Xaddr == xaddr {
+					fmt.Println(nvtDevices[c].params.Xaddr, "==", xaddr)
 					break
 				}
 			}
+
 			if c < len(nvtDevices) {
 				continue
 			}
-			dev, err := NewDevice(strings.Split(xaddr, " ")[0])
-			//fmt.Println(dev)
+
+			dev, err := NewDevice(DeviceParams{Xaddr: strings.Split(xaddr, " ")[0]})
+
 			if err != nil {
 				fmt.Println("Error", xaddr)
 				fmt.Println(err)
 				continue
 			} else {
-				////fmt.Println(dev)
 				nvtDevices = append(nvtDevices, *dev)
 			}
 		}
-		////fmt.Println(j)
-		//nvtDevices[i] = NewDevice()
 	}
+
 	return nvtDevices
 }
 
 func (dev *Device) getSupportedServices(resp *http.Response) {
-	//resp, err := dev.CallMethod(device.GetCapabilities{Category:"All"})
-	//if err != nil {
-	//	log.Println(err.Error())
-	//return
-	//} else {
 	doc := etree.NewDocument()
 
 	data, _ := ioutil.ReadAll(resp.Body)
@@ -159,28 +165,27 @@ func (dev *Device) getSupportedServices(resp *http.Response) {
 	}
 	services := doc.FindElements("./Envelope/Body/GetCapabilitiesResponse/Capabilities/*/XAddr")
 	for _, j := range services {
-		////fmt.Println(j.Text())
-		////fmt.Println(j.Parent().Tag)
 		dev.addEndpoint(j.Parent().Tag, j.Text())
 	}
-	//}
 }
 
 //NewDevice function construct a ONVIF Device entity
-func NewDevice(xaddr string) (*Device, error) {
+func NewDevice(params DeviceParams) (*Device, error) {
 	dev := new(Device)
-	dev.xaddr = xaddr
+	dev.params = params
 	dev.endpoints = make(map[string]string)
-	dev.addEndpoint("Device", "http://"+xaddr+"/onvif/device_service")
+	dev.addEndpoint("Device", "http://"+dev.params.Xaddr+"/onvif/device_service")
+
+	if dev.params.HttpClient == nil {
+		dev.params.HttpClient = new(http.Client)
+	}
 
 	getCapabilities := device.GetCapabilities{Category: "All"}
 
 	resp, err := dev.CallMethod(getCapabilities)
-	//fmt.Println(resp.Request.Host)
-	//fmt.Println(readResponse(resp))
+
 	if err != nil || resp.StatusCode != http.StatusOK {
-		//panic(errors.New("camera is not available at " + xaddr + " or it does not support ONVIF services"))
-		return nil, errors.New("camera is not available at " + xaddr + " or it does not support ONVIF services")
+		return nil, errors.New("camera is not available at " + dev.params.Xaddr + " or it does not support ONVIF services")
 	}
 
 	dev.getSupportedServices(resp)
@@ -188,20 +193,17 @@ func NewDevice(xaddr string) (*Device, error) {
 }
 
 func (dev *Device) addEndpoint(Key, Value string) {
-
 	//use lowCaseKey
 	//make key having ability to handle Mixed Case for Different vendor devcie (e.g. Events EVENTS, events)
 	lowCaseKey := strings.ToLower(Key)
-	dev.endpoints[lowCaseKey] = Value
-}
 
-//Authenticate function authenticate client in the ONVIF device.
-//Function takes <username> and <password> params.
-//You should use this function to allow authorized requests to the ONVIF Device
-//To change auth data call this function again.
-func (dev *Device) Authenticate(username, password string) {
-	dev.login = username
-	dev.password = password
+	// Replace host with host from device params.
+	if u, err := url.Parse(Value); err == nil {
+		u.Host = dev.params.Xaddr
+		Value = u.String()
+	}
+
+	dev.endpoints[lowCaseKey] = Value
 }
 
 //GetEndpoint returns specific ONVIF service endpoint address
@@ -209,7 +211,7 @@ func (dev *Device) GetEndpoint(name string) string {
 	return dev.endpoints[name]
 }
 
-func buildMethodSOAP(msg string) (gosoap.SoapMessage, error) {
+func (dev Device) buildMethodSOAP(msg string) (gosoap.SoapMessage, error) {
 	doc := etree.NewDocument()
 	if err := doc.ReadFromString(msg); err != nil {
 		//log.Println("Got error")
@@ -220,7 +222,6 @@ func buildMethodSOAP(msg string) (gosoap.SoapMessage, error) {
 
 	soap := gosoap.NewEmptySOAP()
 	soap.AddBodyContent(element)
-	//soap.AddRootNamespace("onvif", "http://www.onvif.org/ver10/device/wsdl")
 
 	return soap, nil
 }
@@ -261,41 +262,23 @@ func (dev Device) CallMethod(method interface{}) (*http.Response, error) {
 
 //CallMethod functions call an method, defined <method> struct with authentication data
 func (dev Device) callMethodDo(endpoint string, method interface{}) (*http.Response, error) {
-	/*
-		Converting <method> struct to xml string representation
-	*/
 	output, err := xml.MarshalIndent(method, "  ", "    ")
 	if err != nil {
-		//log.Printf("error: %v\n", err.Error())
 		return nil, err
 	}
-	//fmt.Println(gosoap.SoapMessage(string(output)).StringIndent())
-	/*
-		Build an SOAP request with <method>
-	*/
-	soap, err := buildMethodSOAP(string(output))
+
+	soap, err := dev.buildMethodSOAP(string(output))
 	if err != nil {
-		//log.Printf("error: %v\n", err.Error())
 		return nil, err
 	}
 
-	//fmt.Println(soap.StringIndent())
-	/*
-		Adding namespaces and WS-Security headers
-	*/
 	soap.AddRootNamespaces(Xlmns)
-
-	//fmt.Println(soap.StringIndent())
-	//Header handling
 	soap.AddAction()
 
 	//Auth Handling
-	if dev.login != "" && dev.password != "" {
-		soap.AddWSSecurity(dev.login, dev.password)
+	if dev.params.Username != "" && dev.params.Password != "" {
+		soap.AddWSSecurity(dev.params.Username, dev.params.Password)
 	}
-	//fmt.Println(soap.StringIndent())
-	/*
-		Sending request and returns the response
-	*/
-	return networking.SendSoap(endpoint, soap.String())
+
+	return networking.SendSoap(dev.params.HttpClient, endpoint, soap.String())
 }

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 Yakovlev Dmitry, Zhorzh Palanjyan,Crazybber
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,4 +1,4 @@
-# onvif[golang]
+# onvif protocol
 
 Simple management of onvif IP-devices cameras. onvif is an implementation of  ONVIF protocol for managing onvif IP devices. The purpose of this library is convenient and easy management of IP cameras and other devices that support ONVIF standard.
 
@@ -13,13 +13,16 @@ go get github.com/use-go/onvif
 
 ## Supported services
 
-The following services are fully implemented:
+The following services are implemented:
 
 - Device
 - Media
 - PTZ
 - Imaging
 - Event
+- Discovery
+- Auth(More Options)
+- Soap
 
 ## Using
 
@@ -35,7 +38,7 @@ The following services are fully implemented:
 If there is a device on the network at the address *192.168.13.42*, and its ONVIF services use the *1234* port, then you can connect to the device in the following way:
 
 ```go
-dev, err := onvif.NewDevice("192.168.13.42:1234")
+dev, err := onvif.NewDevice(onvif.DeviceParams{Xaddr: "192.168.13.42:1234"})
 ```
 
 *The ONVIF port may differ depending on the device , to find out which port to use, you can go to the web interface of the device. **Usually this is 80 port.***
@@ -45,8 +48,7 @@ dev, err := onvif.NewDevice("192.168.13.42:1234")
 If any function of the ONVIF services requires authentication, you must use the `Authenticate` method.
 
 ```go
-device := onvif.NewDevice("192.168.13.42:1234")
-device.Authenticate("username", "password")
+device := onvif.NewDevice(onvif.DeviceParams{Xaddr: "192.168.13.42:1234", Username: "username", Password: password})
 ```
 
 #### Defining Data Types
@@ -91,11 +93,11 @@ To perform any function of one of the ONVIF services whose structure has been de
 
 ```go
 createUsers := device.CreateUsers{User: onvif.User{Username:"admin", Password:"qwerty", UserLevel:"User"}}
-device := onvif.NewDevice("192.168.13.42:1234")
+device := onvif.NewDevice(onvif.DeviceParams{Xaddr: "192.168.13.42:1234", Username: "username", Password: password})
 device.Authenticate("username", "password")
 resp, err := dev.CallMethod(createUsers)
 ```
 
 ## Great Thanks
 
-Modified from: [goonvif](https://github.com/yakovlevdmv/goonvif)
+Enhanced and Improved from: [goonvif](https://github.com/yakovlevdmv/goonvif)

api/api.go

@@ -147,7 +147,7 @@ func callNecessaryMethod(serviceName, methodName, acceptedData, username, passwo
 	soap.AddRootNamespaces(onvif.Xlmns)
 	soap.AddWSSecurity(username, password)
 
-	servResp, err := networking.SendSoap(endpoint, soap.String())
+	servResp, err := networking.SendSoap(new(http.Client), endpoint, soap.String())
 	if err != nil {
 		return "", err
 	}
@@ -161,7 +161,7 @@ func callNecessaryMethod(serviceName, methodName, acceptedData, username, passwo
 }
 
 func getEndpoint(service, xaddr string) (string, error) {
-	dev, err := onvif.NewDevice(xaddr)
+	dev, err := onvif.NewDevice(onvif.DeviceParams{Xaddr: xaddr})
 	if err != nil {
 		return "", err
 	}

examples/DeviceService.go

@@ -27,12 +27,15 @@ func readResponse(resp *http.Response) string {
 
 func main() {
 	//Getting an camera instance
-	dev, err := goonvif.NewDevice("192.168.13.14:80")
+	dev, err := goonvif.NewDevice(goonvif.DeviceParams{
+		Xaddr:      "192.168.13.14:80",
+		Username:   login,
+		Password:   password,
+		HttpClient: new(http.Client),
+	})
 	if err != nil {
 		panic(err)
 	}
-	//Authorization
-	dev.Authenticate(login, password)
 
 	//Preparing commands
 	systemDateAndTyme := device.GetSystemDateAndTime{}

examples/discovery_test.go

@@ -0,0 +1,83 @@
+package example
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"path"
+	"regexp"
+	"strings"
+	"testing"
+
+	"github.com/beevik/etree"
+	"github.com/use-go/onvif"
+	"github.com/use-go/onvif/device"
+	discover "github.com/use-go/onvif/ws-discovery"
+)
+
+func TestGetAvailableDevicesAtSpecificEthernetInterface(t *testing.T) {
+
+	// client()
+	// runDiscovery("en0")
+	s := onvif.GetAvailableDevicesAtSpecificEthernetInterface("en0")
+
+	log.Printf("%s", s)
+}
+
+func client() {
+	dev, err := onvif.NewDevice(onvif.DeviceParams{Xaddr: "192.168.3.10", Username: "admin", Password: "zsyy12345"})
+	if err != nil {
+		panic(err)
+	}
+
+	log.Printf("output %+v", dev.GetServices())
+
+	res, err := dev.CallMethod(device.GetUsers{})
+	bs, _ := ioutil.ReadAll(res.Body)
+	log.Printf("output %+v %s", res.StatusCode, bs)
+}
+
+// Host host
+type Host struct {
+	URL  string `json:"url"`
+	Name string `json:"name"`
+}
+
+func runDiscovery(interfaceName string) {
+	var hosts []*Host
+	devices := discover.SendProbe(interfaceName, nil, []string{"dn:NetworkVideoTransmitter"}, map[string]string{"dn": "http://www.onvif.org/ver10/network/wsdl"})
+	for _, j := range devices {
+		doc := etree.NewDocument()
+		if err := doc.ReadFromString(j); err != nil {
+			log.Printf("error %s", err)
+		} else {
+
+			endpoints := doc.Root().FindElements("./Body/ProbeMatches/ProbeMatch/XAddrs")
+			scopes := doc.Root().FindElements("./Body/ProbeMatches/ProbeMatch/Scopes")
+
+			flag := false
+
+			host := &Host{}
+
+			for _, xaddr := range endpoints {
+				xaddr := strings.Split(strings.Split(xaddr.Text(), " ")[0], "/")[2]
+				host.URL = xaddr
+			}
+			if flag {
+				break
+			}
+			for _, scope := range scopes {
+				re := regexp.MustCompile(`onvif:\/\/www\.onvif\.org\/name\/[A-Za-z0-9-]+`)
+				match := re.FindStringSubmatch(scope.Text())
+				host.Name = path.Base(match[0])
+			}
+
+			hosts = append(hosts, host)
+
+		}
+
+	}
+
+	bys, _ := json.Marshal(hosts)
+	log.Printf("done %s", bys)
+}

go.mod

@@ -1,12 +1,11 @@
 module github.com/use-go/onvif
 
-go 1.14
+go 1.15
 
 require (
 	github.com/beevik/etree v1.1.0
 	github.com/elgs/gostrgen v0.0.0-20161222160715-9d61ae07eeae
 	github.com/gin-gonic/gin v1.6.2
 	github.com/gofrs/uuid v3.2.0+incompatible
-	github.com/yakovlevdmv/Golang-iso8601-duration v0.0.0-20180403125811-e5db0413b903
 	golang.org/x/net v0.0.0-20200425230154-ff2c4b7c35a0
 )

go.sum

@@ -42,8 +42,6 @@ github.com/ugorji/go v1.1.7 h1:/68gy2h+1mWMrwZFeD1kQialdSzAb432dtpeJ42ovdo=
 github.com/ugorji/go v1.1.7/go.mod h1:kZn38zHttfInRq0xu/PH0az30d+z6vm202qpg1oXVMw=
 github.com/ugorji/go/codec v1.1.7 h1:2SvQaVZ1ouYrrKKwoSk2pzd4A9evlKJb9oTL+OaLUSs=
 github.com/ugorji/go/codec v1.1.7/go.mod h1:Ax+UKWsSmolVDwsd+7N3ZtXu+yMGCf907BLYF3GoBXY=
-github.com/yakovlevdmv/Golang-iso8601-duration v0.0.0-20180403125811-e5db0413b903 h1:W1Y09qPuFslSd+3famnSJpy4c3My7Gp1cgk5x4ZlbfU=
-github.com/yakovlevdmv/Golang-iso8601-duration v0.0.0-20180403125811-e5db0413b903/go.mod h1:9o96byDMk+osDZqiIS2a7E7y0cWmg4rRTjQRWVHpFWE=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20200425230154-ff2c4b7c35a0 h1:Jcxah/M+oLZ/R4/z5RzfPzGbPXnVDPkEDtf2JnuxN+U=
 golang.org/x/net v0.0.0-20200425230154-ff2c4b7c35a0/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=

gosoap/ws-security.go

@@ -62,18 +62,19 @@ func NewSecurity(username, passwd string) Security {
 	charSet := gostrgen.Lower | gostrgen.Digit
 
 	nonceSeq, _ := gostrgen.RandGen(charsToGenerate, charSet, "", "")
+	created := time.Now().UTC().Format(time.RFC3339Nano)
 	auth := Security{
 		Auth: wsAuth{
 			Username: username,
 			Password: password{
 				Type:     passwordType,
-				Password: generateToken(username, nonceSeq, time.Now().UTC(), passwd),
+				Password: generateToken(username, nonceSeq, created, passwd),
 			},
 			Nonce: nonce{
 				Type:  encodingType,
 				Nonce: nonceSeq,
 			},
-			Created: time.Now().UTC().Format(time.RFC3339Nano),
+			Created: created,
 		},
 	}
 
@@ -81,13 +82,11 @@ func NewSecurity(username, passwd string) Security {
 }
 
 //Digest = B64ENCODE( SHA1( B64DECODE( Nonce ) + Date + Password ) )
-func generateToken(Username string, Nonce string, Created time.Time, Password string) string {
-
+func generateToken(Username string, Nonce string, Created string, Password string) string {
 	sDec, _ := base64.StdEncoding.DecodeString(Nonce)
 
 	hasher := sha1.New()
-	//hasher.Write([]byte((base64.StdEncoding.EncodeToString([]byte(Nonce)) + Created.Format(time.RFC3339) + Password)))
-	hasher.Write([]byte(string(sDec) + Created.Format(time.RFC3339Nano) + Password))
+	hasher.Write([]byte(string(sDec) + Created + Password))
 
 	return base64.StdEncoding.EncodeToString(hasher.Sum(nil))
 }

networking/networking.go

@@ -1,17 +1,16 @@
 package networking
 
 import (
-	"net/http"
 	"bytes"
+	"net/http"
 )
 
-func SendSoap(endpoint, message string) (*http.Response, error) {
-	httpClient := new(http.Client)
-
+// SendSoap send soap message
+func SendSoap(httpClient *http.Client, endpoint, message string) (*http.Response, error) {
 	resp, err := httpClient.Post(endpoint, "application/soap+xml; charset=utf-8", bytes.NewBufferString(message))
 	if err != nil {
 		return resp, err
 	}
 
-	return resp,nil
-}
+	return resp, nil
+}

ws-discovery/networking.go

@@ -10,9 +10,11 @@ package wsdiscovery
  *******************************************************/
 
 import (
+	"errors"
 	"fmt"
 	"log"
 	"net"
+	"os"
 	"time"
 
 	"github.com/gofrs/uuid"
@@ -85,7 +87,9 @@ func sendUDPMulticast(msg string, interfaceName string) []string {
 		b := make([]byte, bufSize)
 		n, _, _, err := p.ReadFrom(b)
 		if err != nil {
-			fmt.Println(err)
+			if !errors.Is(err, os.ErrDeadlineExceeded) {
+				fmt.Println(err)
+			}
 			break
 		}
 		result = append(result, string(b[0:n]))

xsd/built_in.go

@@ -11,7 +11,7 @@ import (
 	"strings"
 	"time"
 
-	iso8601 "github.com/yakovlevdmv/Golang-iso8601-duration"
+	"github.com/use-go/onvif/xsd/iso8601"
 )
 
 /*

xsd/iso8601/iso8601_duration.go

@@ -0,0 +1,104 @@
+package iso8601
+
+import (
+	"errors"
+	"regexp"
+)
+
+//Duration of iso8601
+type Duration struct {
+	years  string //= number of years
+	months string //= number of months
+	days   string //= number of days
+	// Time section
+	hours   string //= the number of hours
+	minutes string //= the number of minutes
+	seconds string //= the number of seconds
+}
+
+//NewDuration return duration
+func NewDuration(years, months, days, hours, minutes, seconds string) (*Duration, error) {
+	// Pattern for Years, Months, Days, Hours and Minutes components
+	pattern1 := "^$|[0-9]+"
+	// Pattern for Seconds component
+	pattern2 := "^$|[0-9]+(\\.[0-9]+)?"
+
+	matched, err := regexp.MatchString(pattern1, years)
+	if err != nil {
+		return nil, err
+	} else if !matched {
+		return nil, errors.New("years value = " + years + " does not match pattern " + pattern1)
+	}
+
+	matched, err = regexp.MatchString(pattern1, months)
+	if err != nil {
+		return nil, err
+	} else if !matched {
+		return nil, errors.New("months value = " + months + " does not match pattern " + pattern1)
+	}
+
+	matched, err = regexp.MatchString(pattern1, days)
+	if err != nil {
+		return nil, err
+	} else if !matched {
+		return nil, errors.New("months value = " + days + " does not match pattern " + pattern1)
+	}
+
+	matched, err = regexp.MatchString(pattern1, hours)
+	if err != nil {
+		return nil, err
+	} else if !matched {
+		return nil, errors.New("months value = " + hours + " does not match pattern " + pattern1)
+	}
+
+	matched, err = regexp.MatchString(pattern1, minutes)
+	if err != nil {
+		return nil, err
+	} else if !matched {
+		return nil, errors.New("months value = " + minutes + " does not match pattern " + pattern1)
+	}
+
+	matched, err = regexp.MatchString(pattern2, seconds)
+	if err != nil {
+		return nil, err
+	} else if !matched {
+		return nil, errors.New("years value = " + seconds + " does not match pattern " + pattern2)
+	}
+
+	return &Duration{years: years, months: months, hours: hours, days: days, minutes: minutes, seconds: seconds}, nil
+}
+
+//ISO8601Duration to string
+func (duration Duration) ISO8601Duration() string {
+	var result string
+	result += "P" // time duration designator
+	//years
+	if duration.years != "" {
+		result += duration.years + "Y"
+	}
+	if duration.months != "" {
+		result += duration.months + "M"
+	}
+	if duration.days != "" {
+		result += duration.days + "D"
+	}
+
+	if duration.hours != "" && duration.minutes != "" && duration.seconds != "" {
+		result += "T"
+		if duration.hours != "" {
+			result += duration.hours + "H"
+		}
+		if duration.minutes != "" {
+			result += duration.minutes + "M"
+		}
+		if duration.seconds != "" {
+			result += duration.seconds + "S"
+		}
+	}
+
+	if len(result) == 1 {
+		result += "T0S"
+	}
+
+	return result
+}