Simplify component writing and make it similar to client

_examples/xmpp_component/xmpp_component.go

@@ -8,31 +8,36 @@ import (
 )
 
 func main() {
-	component := MyComponent{Name: "Test Component", Category: "gateway", Type: "service"}
-	component.xmpp = &xmpp.Component{Host: "service.localhost", Secret: "mypass"}
-	if err := component.xmpp.Connect("localhost:8888"); err != nil {
+	opts := xmpp.ComponentOptions{
+		Domain:   "service.localhost",
+		Secret:   "mypass",
+		Address:  "localhost:8888",
+		Name:     "Test Component",
+		Category: "gateway",
+		Type:     "service",
+	}
+	component, err := xmpp.NewComponent(opts)
+	if err != nil {
+		log.Fatalf("%+v", err)
+	}
+
+	// If you pass the component to a connection manager, it will handle the reconnect policy
+	// for you automatically.
+	cm := xmpp.NewStreamManager(component, nil)
+	err = cm.Start()
+	if err != nil {
 		log.Fatal(err)
 	}
 
-	for {
-		packet, err := component.xmpp.ReadPacket()
-		if err != nil {
-			fmt.Println("read error", err)
-			return
-		}
-
+	// Iterator to receive packets coming from our XMPP connection
+	for packet := range component.Recv() {
 		switch p := packet.(type) {
 		case xmpp.IQ:
 			switch inner := p.Payload[0].(type) {
-			case *xmpp.DiscoInfo:
-				fmt.Println("Disco Info")
-				if p.Type == "get" {
-					DiscoResult(component, p.PacketAttrs, inner)
-				}
 			case *xmpp.DiscoItems:
 				fmt.Println("DiscoItems")
 				if p.Type == "get" {
-					DiscoItems(component, p.PacketAttrs, inner)
+					discoItems(component, p.PacketAttrs, inner)
 				}
 			default:
 				fmt.Println("ignoring iq packet", inner)
@@ -42,7 +47,7 @@ func main() {
 					Type:   "cancel",
 				}
 				reply := p.MakeError(xError)
-				_ = component.xmpp.Send(&reply)
+				_ = component.Send(&reply)
 			}
 
 		case xmpp.Message:
@@ -57,39 +62,7 @@ func main() {
 	}
 }
 
-type MyComponent struct {
-	Name string
-	// Typical categories and types: https://xmpp.org/registrar/disco-categories.html
-	Category string
-	Type     string
-
-	xmpp *xmpp.Component
-}
-
-func DiscoResult(c MyComponent, attrs xmpp.PacketAttrs, info *xmpp.DiscoInfo) {
-	iq := xmpp.NewIQ("result", attrs.To, attrs.From, attrs.Id, "en")
-	var identity xmpp.Identity
-	if info.Node == "" {
-		identity = xmpp.Identity{
-			Name:     c.Name,
-			Category: c.Category,
-			Type:     c.Type,
-		}
-	}
-
-	payload := xmpp.DiscoInfo{
-		Identity: identity,
-		Features: []xmpp.Feature{
-			{Var: xmpp.NSDiscoInfo},
-			{Var: xmpp.NSDiscoItems},
-		},
-	}
-	iq.AddPayload(&payload)
-
-	_ = c.xmpp.Send(iq)
-}
-
-func DiscoItems(c MyComponent, attrs xmpp.PacketAttrs, items *xmpp.DiscoItems) {
+func discoItems(c *xmpp.Component, attrs xmpp.PacketAttrs, items *xmpp.DiscoItems) {
 	iq := xmpp.NewIQ("result", attrs.To, attrs.From, attrs.Id, "en")
 
 	var payload xmpp.DiscoItems
@@ -101,5 +74,5 @@ func DiscoItems(c MyComponent, attrs xmpp.PacketAttrs, items *xmpp.DiscoItems) {
 		}
 	}
 	iq.AddPayload(&payload)
-	_ = c.xmpp.Send(iq)
+	_ = c.Send(iq)
 }

component.go

@@ -9,16 +9,47 @@ import (
 	"io"
 	"net"
 	"time"
+
+	"gosrc.io/xmpp"
 )
 
 const componentStreamOpen = "<?xml version='1.0'?><stream:stream to='%s' xmlns='%s' xmlns:stream='%s'>"
 
+type ComponentOptions struct {
+	// =================================
+	// Component Connection Info
+
+	// Domain is the XMPP server subdomain that the component will handle
+	Domain string
+	// Secret is the "password" used by the XMPP server to secure component access
+	Secret string
+	// Address is the XMPP Host and port to connect to. Host is of
+	// the form 'serverhost:port' i.e "localhost:8888"
+	Address string
+
+	// =================================
+	// Component discovery
+
+	// Component human readable name, that will be shown in XMPP discovery
+	Name string
+	// Typical categories and types: https://xmpp.org/registrar/disco-categories.html
+	Category string
+	Type     string
+
+	// =================================
+	// Communication with developer client / StreamManager
+
+	// Packet channel
+	RecvChannel chan interface{}
+	// Track and broadcast connection state
+	EventManager
+}
+
 // Component implements an XMPP extension allowing to extend XMPP server
 // using external components. Component specifications are defined
 // in XEP-0114, XEP-0355 and XEP-0356.
 type Component struct {
-	Host   string
-	Secret string
+	ComponentOptions
 
 	// TCP level connection
 	conn net.Conn
@@ -28,18 +59,22 @@ type Component struct {
 	decoder     *xml.Decoder
 }
 
+func NewComponent(opts ComponentOptions) (*Component, error) {
+	return &Component{ComponentOptions: opts}, nil
+}
+
 // Connect triggers component connection to XMPP server component port.
-// TODO Helper to prepare connection string
-func (c *Component) Connect(connStr string) error {
+// TODO: Failed handshake should be a permanent error
+func (c *Component) Connect() error {
 	var conn net.Conn
 	var err error
-	if conn, err = net.DialTimeout("tcp", connStr, time.Duration(5)*time.Second); err != nil {
+	if conn, err = net.DialTimeout("tcp", c.Address, time.Duration(5)*time.Second); err != nil {
 		return err
 	}
 	c.conn = conn
 
 	// 1. Send stream open tag
-	if _, err := fmt.Fprintf(conn, componentStreamOpen, c.Host, NSComponent, NSStream); err != nil {
+	if _, err := fmt.Fprintf(conn, componentStreamOpen, c.Domain, NSComponent, NSStream); err != nil {
 		return errors.New("cannot send stream open " + err.Error())
 	}
 	c.decoder = xml.NewDecoder(conn)
@@ -65,16 +100,59 @@ func (c *Component) Connect(connStr string) error {
 	case StreamError:
 		return errors.New("handshake failed " + v.Error.Local)
 	case Handshake:
+		// Start the receiver go routine
+		go c.recv()
 		return nil
 	default:
-		return errors.New("unexpected packet, got " + v.Name())
+		return errors.New("expecting handshake result, got " + v.Name())
 	}
 }
 
-// ReadPacket reads next incoming XMPP packet
-func (c *Component) ReadPacket() (Packet, error) {
-	// TODO use defined interface Packet
-	return next(c.decoder)
+func (c *Component) Disconnect() {
+	_ = c.SendRaw("</stream:stream>")
+	// TODO: Add a way to wait for stream close acknowledgement from the server for clean disconnect
+	_ = c.conn.Close()
+}
+
+func (c *Component) SetHandler(handler EventHandler) {
+	c.Handler = handler
+}
+
+// Recv abstracts receiving preparsed XMPP packets from a channel.
+// Channel allow client to receive / dispatch packets in for range loop.
+// TODO: Deprecate this function in favor of reading directly from the RecvChannel ?
+func (c *Component) Recv() <-chan interface{} {
+	return c.RecvChannel
+}
+
+func (c *Component) recv() (err error) {
+	for {
+		val, err := next(c.decoder)
+		if err != nil {
+			c.updateState(StateDisconnected)
+			return err
+		}
+
+		// Handle stream errors
+		switch p := val.(type) {
+		case StreamError:
+			c.RecvChannel <- val
+			close(c.RecvChannel)
+			c.streamError(p.Error.Local, p.Text)
+			return errors.New("stream error: " + p.Error.Local)
+		case xmpp.IQ:
+			switch inner := p.Payload[0].(type) {
+			// Our component module handle disco info but can let component implementation
+			// handle disco items queries
+			case *xmpp.DiscoInfo:
+				if p.Type == "get" {
+					c.discoResult(p.PacketAttrs, inner)
+				}
+			}
+			break
+		}
+		c.RecvChannel <- val
+	}
 }
 
 // Send marshalls XMPP stanza and sends it to the server.
@@ -142,3 +220,28 @@ func (handshakeDecoder) decode(p *xml.Decoder, se xml.StartElement) (Handshake,
 	err := p.DecodeElement(&packet, &se)
 	return packet, err
 }
+
+// Service discovery
+
+func (c *Component) discoResult(attrs xmpp.PacketAttrs, info *xmpp.DiscoInfo) {
+	iq := xmpp.NewIQ("result", attrs.To, attrs.From, attrs.Id, "en")
+	var identity xmpp.Identity
+	if info.Node == "" {
+		identity = xmpp.Identity{
+			Name:     c.Name,
+			Category: c.Category,
+			Type:     c.Type,
+		}
+	}
+
+	payload := xmpp.DiscoInfo{
+		Identity: identity,
+		Features: []xmpp.Feature{
+			{Var: xmpp.NSDiscoInfo},
+			{Var: xmpp.NSDiscoItems},
+		},
+	}
+	iq.AddPayload(&payload)
+
+	_ = c.xmpp.Send(iq)
+}