Implement a bit of XEP-0060 (PubSub) (#119)

This squashed series of commits implements basic
PubSub functionality like requesting data or
subscribing to a PubSub node.

xmpp_pubsub.go

@@ -0,0 +1,133 @@
+package xmpp
+
+import (
+	"encoding/xml"
+	"fmt"
+)
+
+const (
+	XMPPNS_PUBSUB       = "http://jabber.org/protocol/pubsub"
+	XMPPNS_PUBSUB_EVENT = "http://jabber.org/protocol/pubsub#event"
+)
+
+type clientPubsubItem struct {
+	XMLName xml.Name `xml:"item"`
+	ID      string   `xml:"id,attr"`
+	Body    []byte   `xml:",innerxml"`
+}
+
+type clientPubsubItems struct {
+	XMLName xml.Name           `xml:"items"`
+	Node    string             `xml:"node,attr"`
+	Items   []clientPubsubItem `xml:"item"`
+}
+
+type clientPubsub struct {
+	XMLName xml.Name          `xml:"pubsub"`
+	Items   clientPubsubItems `xml:"items"`
+}
+
+type clientPubsubEvent struct {
+	XMLName xml.Name          `xml:"event"`
+	XMLNS   string            `xml:"xmlns,attr"`
+	Items   clientPubsubItems `xml:"items"`
+}
+
+type clientPubsubError struct {
+	XMLName xml.Name
+}
+
+type clientPubsubSubscription struct {
+	XMLName xml.Name `xml:"subscription"`
+	Node    string   `xml:"node,attr"`
+	JID     string   `xml:"jid,attr"`
+	SubID   string   `xml:"subid,attr"`
+}
+
+type PubsubEvent struct {
+	Node  string
+	Items []PubsubItem
+}
+
+type PubsubSubscription struct {
+	SubID  string
+	JID    string
+	Node   string
+	Errors []string
+}
+type PubsubUnsubscription PubsubSubscription
+
+type PubsubItem struct {
+	ID       string
+	InnerXML []byte
+}
+
+type PubsubItems struct {
+	Node  string
+	Items []PubsubItem
+}
+
+// Converts []clientPubsubItem to []PubsubItem
+func pubsubItemsToReturn(items []clientPubsubItem) []PubsubItem {
+	var tmp []PubsubItem
+	for _, i := range items {
+		tmp = append(tmp, PubsubItem{
+			ID:       i.ID,
+			InnerXML: i.Body,
+		})
+	}
+
+	return tmp
+}
+
+func pubsubClientToReturn(event clientPubsubEvent) PubsubEvent {
+	return PubsubEvent{
+		Node:  event.Items.Node,
+		Items: pubsubItemsToReturn(event.Items.Items),
+	}
+}
+
+func pubsubStanza(body string) string {
+	return fmt.Sprintf("<pubsub xmlns='%s'>%s</pubsub>",
+		XMPPNS_PUBSUB, body)
+}
+
+func pubsubSubscriptionStanza(node, jid string) string {
+	body := fmt.Sprintf("<subscribe node='%s' jid='%s'/>",
+		xmlEscape(node),
+		xmlEscape(jid))
+	return pubsubStanza(body)
+}
+
+func pubsubUnsubscriptionStanza(node, jid string) string {
+	body := fmt.Sprintf("<unsubscribe node='%s' jid='%s'/>",
+		xmlEscape(node),
+		xmlEscape(jid))
+	return pubsubStanza(body)
+}
+
+func (c *Client) PubsubSubscribeNode(node, jid string) {
+	c.RawInformation(c.jid,
+		jid,
+		"sub1",
+		"set",
+		pubsubSubscriptionStanza(node, c.jid))
+}
+
+func (c *Client) PubsubUnsubscribeNode(node, jid string) {
+	c.RawInformation(c.jid,
+		jid,
+		"unsub1",
+		"set",
+		pubsubUnsubscriptionStanza(node, c.jid))
+}
+
+func (c *Client) PubsubRequestLastItems(node, jid string) {
+	body := fmt.Sprintf("<items node='%s'/>", node)
+	c.RawInformation(c.jid, jid, "items1", "get", pubsubStanza(body))
+}
+
+func (c *Client) PubsubRequestItem(node, jid, id string) {
+	body := fmt.Sprintf("<items node='%s'><item id='%s'/></items>", node, id)
+	c.RawInformation(c.jid, jid, "items3", "get", pubsubStanza(body))
+}