PubSub protocol support (#142)

* PubSub protocol support
Added support for :
- XEP-0050   (Command))
- XEP-0060   (PubSub)
- XEP-0004   (Forms)

Fixed the NewClient function by adding parsing of the domain from the JID if no domain is provided in transport config.
Updated xmpp_jukebox example

* Delete useless pubsub errors

* README.md update
Fixed import in echo example

* Typo

* Fixed raw send on client example

* Fixed jukebox example and added a README.md

stanza/form_test.go

@@ -0,0 +1,107 @@
+package stanza
+
+import (
+	"encoding/xml"
+	"strings"
+	"testing"
+)
+
+const (
+	formSubmit = "<pubsub xmlns=\"http://jabber.org/protocol/pubsub#owner\">" +
+		"<configure node=\"princely_musings\">" +
+		"<x xmlns=\"jabber:x:data\" type=\"submit\">" +
+		"<field var=\"FORM_TYPE\" type=\"hidden\">" +
+		"<value>http://jabber.org/protocol/pubsub#node_config</value>" +
+		"</field>" +
+		"<field var=\"pubsub#title\">" +
+		"<value>Princely Musings (Atom)</value>" +
+		"</field>" +
+		"<field var=\"pubsub#deliver_notifications\">" +
+		"<value>1</value>" +
+		"</field>" +
+		"<field var=\"pubsub#access_model\">" +
+		"<value>roster</value>" +
+		"</field>" +
+		"<field var=\"pubsub#roster_groups_allowed\">" +
+		"<value>friends</value>" +
+		"<value>servants</value>" +
+		"<value>courtiers</value>" +
+		"</field>" +
+		"<field var=\"pubsub#type\">" +
+		"<value>http://www.w3.org/2005/Atom</value>" +
+		"</field>" +
+		"<field var=\"pubsub#notification_type\" type=\"list-single\"" +
+		"label=\"Specify the delivery style for event notifications\">" +
+		"<value>headline</value>" +
+		"<option>" +
+		"<value>normal</value>" +
+		"</option>" +
+		"<option>" +
+		"<value>headline</value>" +
+		"</option>" +
+		"</field>" +
+		"</x>" +
+		"</configure>" +
+		"</pubsub>"
+
+	clientJid   = "hamlet@denmark.lit/elsinore"
+	serviceJid  = "pubsub.shakespeare.lit"
+	iqId        = "config1"
+	serviceNode = "princely_musings"
+)
+
+func TestMarshalFormSubmit(t *testing.T) {
+	formIQ := NewIQ(Attrs{From: clientJid, To: serviceJid, Id: iqId, Type: IQTypeSet})
+	formIQ.Payload = &PubSubOwner{
+		OwnerUseCase: &ConfigureOwner{
+			Node: serviceNode,
+			Form: &Form{
+				Type: FormTypeSubmit,
+				Fields: []Field{
+					{Var: "FORM_TYPE", Type: FieldTypeHidden, ValuesList: []string{"http://jabber.org/protocol/pubsub#node_config"}},
+					{Var: "pubsub#title", ValuesList: []string{"Princely Musings (Atom)"}},
+					{Var: "pubsub#deliver_notifications", ValuesList: []string{"1"}},
+					{Var: "pubsub#access_model", ValuesList: []string{"roster"}},
+					{Var: "pubsub#roster_groups_allowed", ValuesList: []string{"friends", "servants", "courtiers"}},
+					{Var: "pubsub#type", ValuesList: []string{"http://www.w3.org/2005/Atom"}},
+					{
+						Var:        "pubsub#notification_type",
+						Type:       "list-single",
+						Label:      "Specify the delivery style for event notifications",
+						ValuesList: []string{"headline"},
+						Options: []Option{
+							{ValuesList: []string{"normal"}},
+							{ValuesList: []string{"headline"}},
+						},
+					},
+				},
+			},
+		},
+	}
+	b, err := xml.Marshal(formIQ.Payload)
+	if err != nil {
+		t.Fatalf("Could not marshal formIQ : %v", err)
+	}
+
+	if strings.ReplaceAll(string(b), " ", "") != strings.ReplaceAll(formSubmit, " ", "") {
+		t.Fatalf("Expected formIQ and marshalled one are different.\nExepected : %s\nMarshalled : %s", formSubmit, string(b))
+	}
+
+}
+
+func TestUnmarshalFormSubmit(t *testing.T) {
+	var f PubSubOwner
+	mErr := xml.Unmarshal([]byte(formSubmit), &f)
+	if mErr != nil {
+		t.Fatalf("failed to unmarshal formSubmit ! %s", mErr)
+	}
+
+	data, err := xml.Marshal(&f)
+	if err != nil {
+		t.Fatalf("failed to marshal formSubmit")
+	}
+
+	if strings.ReplaceAll(string(data), " ", "") != strings.ReplaceAll(formSubmit, " ", "") {
+		t.Fatalf("failed unmarshal/marshal for formSubmit : %s\n%s", string(data), formSubmit)
+	}
+}