Implementing support for APNS content-mutable field (#126)

* Implementing support for APNS content-mutable field

* Corrected the mutable-content option name

* Renamed CustomFields to CustomData

* Added comment

Author: hiranya911

messaging/messaging.go

@@ -214,36 +214,53 @@ func (p *APNSPayload) MarshalJSON() ([]byte, error) {
 // Alert may be specified as a string (via the AlertString field), or as a struct (via the Alert
 // field).
 type Aps struct {
-	AlertString      string    `json:"-"`
-	Alert            *ApsAlert `json:"-"`
-	Badge            *int      `json:"badge,omitempty"`
-	Sound            string    `json:"sound,omitempty"`
-	ContentAvailable bool      `json:"-"`
-	Category         string    `json:"category,omitempty"`
-	ThreadID         string    `json:"thread-id,omitempty"`
+	AlertString      string
+	Alert            *ApsAlert
+	Badge            *int
+	Sound            string
+	ContentAvailable bool
+	MutableContent   bool
+	Category         string
+	ThreadID         string
+	CustomData       map[string]interface{}
 }
 
-// MarshalJSON marshals an Aps into JSON (for internal use only).
-func (a *Aps) MarshalJSON() ([]byte, error) {
-	type apsAlias Aps
-	s := &struct {
-		Alert            interface{} `json:"alert,omitempty"`
-		ContentAvailable *int        `json:"content-available,omitempty"`
-		*apsAlias
-	}{
-		apsAlias: (*apsAlias)(a),
-	}
-
+// standardFields creates a map containing all the fields except the custom data.
+func (a *Aps) standardFields() map[string]interface{} {
+	m := make(map[string]interface{})
 	if a.Alert != nil {
-		s.Alert = a.Alert
+		m["alert"] = a.Alert
 	} else if a.AlertString != "" {
-		s.Alert = a.AlertString
+		m["alert"] = a.AlertString
 	}
 	if a.ContentAvailable {
-		one := 1
-		s.ContentAvailable = &one
+		m["content-available"] = 1
 	}
-	return json.Marshal(s)
+	if a.MutableContent {
+		m["mutable-content"] = 1
+	}
+	if a.Badge != nil {
+		m["badge"] = *a.Badge
+	}
+	if a.Sound != "" {
+		m["sound"] = a.Sound
+	}
+	if a.Category != "" {
+		m["category"] = a.Category
+	}
+	if a.ThreadID != "" {
+		m["thread-id"] = a.ThreadID
+	}
+	return m
+}
+
+// MarshalJSON marshals an Aps into JSON (for internal use only).
+func (a *Aps) MarshalJSON() ([]byte, error) {
+	m := a.standardFields()
+	for k, v := range a.CustomData {
+		m[k] = v
+	}
+	return json.Marshal(m)
 }
 
 // ApsAlert is the alert payload that can be included in an Aps.

messaging/messaging_test.go

@@ -249,6 +249,7 @@ var validMessages = []struct {
 						Sound:            "s",
 						ThreadID:         "t",
 						ContentAvailable: true,
+						MutableContent:   true,
 					},
 					CustomData: map[string]interface{}{
 						"k1": "v1",
@@ -269,6 +270,7 @@ var validMessages = []struct {
 						"sound":             "s",
 						"thread-id":         "t",
 						"content-available": float64(1),
+						"mutable-content":   float64(1),
 					},
 					"k1": "v1",
 					"k2": true,
@@ -288,6 +290,8 @@ var validMessages = []struct {
 						Sound:            "s",
 						ThreadID:         "t",
 						ContentAvailable: true,
+						MutableContent:   true,
+						CustomData:       map[string]interface{}{"k1": "v1", "k2": 1},
 					},
 				},
 			},
@@ -302,6 +306,9 @@ var validMessages = []struct {
 						"sound":             "s",
 						"thread-id":         "t",
 						"content-available": float64(1),
+						"mutable-content":   float64(1),
+						"k1":                "v1",
+						"k2":                float64(1),
 					},
 				},
 			},
@@ -471,6 +478,21 @@ var invalidMessages = []struct {
 		},
 		want: "multiple alert specifications",
 	},
+	{
+		name: "APNSMultipleFieldSpecifications",
+		req: &Message{
+			APNS: &APNSConfig{
+				Payload: &APNSPayload{
+					Aps: &Aps{
+						Category:   "category",
+						CustomData: map[string]interface{}{"category": "category"},
+					},
+				},
+			},
+			Topic: "topic",
+		},
+		want: `multiple specifications for the key "category"`,
+	},
 	{
 		name: "InvalidAPNSTitleLocArgs",
 		req: &Message{

messaging/messaging_utils.go

@@ -102,6 +102,12 @@ func validateAps(aps *Aps) error {
 		if aps.Alert != nil && aps.AlertString != "" {
 			return fmt.Errorf("multiple alert specifications")
 		}
+		m := aps.standardFields()
+		for k := range aps.CustomData {
+			if _, contains := m[k]; contains {
+				return fmt.Errorf("multiple specifications for the key %q", k)
+			}
+		}
 		return validateApsAlert(aps.Alert)
 	}
 	return nil