Add IQ result routes to the Router

These are used to quickly match IQ result stanzas and invoke a handler
for them. IQ result routes take precendence of normal routes.

router.go

@@ -1,6 +1,7 @@
 package xmpp
 
 import (
+	"context"
 	"encoding/xml"
 	"strings"
 
@@ -25,16 +26,26 @@ TODO: Automatically reply to IQ that do not match any route, to comply to XMPP s
 type Router struct {
 	// Routes to be matched, in order.
 	routes []*Route
+
+	iqResultRoutes map[string]*IqResultRoute
 }
 
 // NewRouter returns a new router instance.
 func NewRouter() *Router {
-	return &Router{}
+	return &Router{
+		iqResultRoutes: make(map[string]*IqResultRoute),
+	}
 }
 
 // route is called by the XMPP client to dispatch stanza received using the set up routes.
 // It is also used by test, but is not supposed to be used directly by users of the library.
 func (r *Router) route(s Sender, p stanza.Packet) {
+	iq, isIq := p.(stanza.IQ)
+	if isIq {
+		if route, ok := r.iqResultRoutes[iq.Id]; ok {
+			route.handler.HandlePacket(s, p)
+		}
+	}
 
 	var match RouteMatch
 	if r.Match(p, &match) {
@@ -42,13 +53,12 @@ func (r *Router) route(s Sender, p stanza.Packet) {
 		match.Handler.HandlePacket(s, p)
 		return
 	}
+
 	// If there is no match and we receive an iq set or get, we need to send a reply
-	if iq, ok := p.(stanza.IQ); ok {
+	if isIq && (iq.Type == stanza.IQTypeGet || iq.Type == stanza.IQTypeSet) {
-		if iq.Type == stanza.IQTypeGet || iq.Type == stanza.IQTypeSet {
 		iqNotImplemented(s, iq)
 	}
 }
-}
 
 func iqNotImplemented(s Sender, iq stanza.IQ) {
 	err := stanza.Err{
@@ -68,6 +78,28 @@ func (r *Router) NewRoute() *Route {
 	return route
 }
 
+// NewIqResultRoute register a route that will catch an IQ result stanza with
+// the given Id. The route will only match ones, after which it will automatically
+// be unregistered
+func (r *Router) NewIqResultRoute(ctx context.Context, id string) *IqResultRoute {
+	route := &IqResultRoute{
+		context: ctx,
+		matched: make(chan struct{}),
+	}
+	r.iqResultRoutes[id] = route
+	go func() {
+		select {
+		case <-route.context.Done():
+			if route.timeoutHandler != nil {
+				route.timeoutHandler(route.context.Err())
+			}
+		case <-route.matched:
+		}
+		delete(r.iqResultRoutes, id)
+	}()
+	return route
+}
+
 func (r *Router) Match(p stanza.Packet, match *RouteMatch) bool {
 	for _, route := range r.routes {
 		if route.Match(p, match) {
@@ -89,6 +121,40 @@ func (r *Router) HandleFunc(name string, f func(s Sender, p stanza.Packet)) *Rou
 	return r.NewRoute().Packet(name).HandlerFunc(f)
 }
 
+// HandleIqResult register a temporary route
+func (r *Router) HandleIqResult(id string, handler Handler) *IqResultRoute {
+	return r.NewIqResultRoute(context.Background(), id).Handler(handler)
+}
+
+func (r *Router) HandleFuncIqResult(id string, f func(s Sender, p stanza.Packet)) *IqResultRoute {
+	return r.NewIqResultRoute(context.Background(), id).HandlerFunc(f)
+}
+
+// ============================================================================
+// IqResultRoute
+type TimeoutHandlerFunc func(err error)
+
+type IqResultRoute struct {
+	context        context.Context
+	matched        chan struct{}
+	handler        Handler
+	timeoutHandler TimeoutHandlerFunc
+}
+
+func (r *IqResultRoute) Handler(handler Handler) *IqResultRoute {
+	r.handler = handler
+	return r
+}
+
+func (r *IqResultRoute) HandlerFunc(f HandlerFunc) *IqResultRoute {
+	return r.Handler(f)
+}
+
+func (r *IqResultRoute) TimeoutHandlerFunc(f TimeoutHandlerFunc) *IqResultRoute {
+	r.timeoutHandler = f
+	return r
+}
+
 // ============================================================================
 // Route
 type Handler interface {