Add support for the apns-push-type header (#139)

* add support for the apns-push-type header

Author: wiggisser

client.go

@@ -208,4 +208,10 @@ func setHeaders(r *http.Request, n *Notification) {
 	if !n.Expiration.IsZero() {
 		r.Header.Set("apns-expiration", fmt.Sprintf("%v", n.Expiration.Unix()))
 	}
+	if n.PushType != "" {
+		r.Header.Set("apns-push-type", string(n.PushType))
+	} else {
+		r.Header.Set("apns-push-type", string(PushTypeAlert))
+	}
+
 }

client_test.go

@@ -16,10 +16,10 @@ import (
 
 	"golang.org/x/net/http2"
 
-	apns "github.com/sideshow/apns2"
 	"github.com/sideshow/apns2/certificate"
 	"github.com/sideshow/apns2/token"
 	"github.com/stretchr/testify/assert"
+	apns "github.com/sideshow/apns2"
 )
 
 // Mocks
@@ -157,6 +157,7 @@ func TestDefaultHeaders(t *testing.T) {
 		assert.Equal(t, "", r.Header.Get("apns-topic"))
 		assert.Equal(t, "", r.Header.Get("apns-expiration"))
 		assert.Equal(t, "", r.Header.Get("thread-id"))
+		assert.Equal(t, "alert", r.Header.Get("apns-push-type"))
 	}))
 	defer server.Close()
 	_, err := mockClient(server.URL).Push(n)
@@ -176,6 +177,11 @@ func TestHeaders(t *testing.T) {
 		assert.Equal(t, "10", r.Header.Get("apns-priority"))
 		assert.Equal(t, n.Topic, r.Header.Get("apns-topic"))
 		assert.Equal(t, fmt.Sprintf("%v", n.Expiration.Unix()), r.Header.Get("apns-expiration"))
+		if n.PushType == "" {
+			assert.Equal(t, "alert", r.Header.Get("apns-push-type"))
+		} else {
+			assert.Equal(t, n.PushType, r.Header.Get("apns-push-type"))
+		}
 	}))
 	defer server.Close()
 	_, err := mockClient(server.URL).Push(n)

notification.go

@@ -5,6 +5,16 @@ import (
 	"time"
 )
 
+//EPushType defines the value for the apns-push-type header
+type EPushType string
+
+const (
+	//PushTypeAlert  will set the apns-push-type header to 'alert'
+	PushTypeAlert EPushType = "alert"
+	//PushTypeBackground will set the apns-push-type header to 'background'
+	PushTypeBackground EPushType = "background"
+)
+
 const (
 	// PriorityLow will tell APNs to send the push message at a time that takes
 	// into account power considerations for the device. Notifications with this
@@ -65,6 +75,10 @@ type Notification struct {
 	// Refer to "The Remote Notification Payload" section in the Apple Local and
 	// Remote Notification Programming Guide for more info.
 	Payload interface{}
+
+	// The pushtype of the push notification. If this values is left as the default
+	// an apns-push-type header with value 'alert' will be added to the http request.
+	PushType EPushType
 }
 
 // MarshalJSON converts the notification payload to JSON.