# Push Messages

Before you can start receiving messages through FCM, you need to setup FCM in your project.

Firebase has a pretty comprehensive tutorial for setting up FCM. Follow the steps [over here](https://firebase.google.com/docs/cloud-messaging/ios/client) and you should be ready to receive messages via FCM.

Now that you’ve configured FCM in your project you can hook it up with Mitter using the following steps:

#### Register a delivery endpoint

Before receiving any messages from Mitter you need to register the device’s FCM token as a delivery endpoint with Mitter.

You can get and register the FCM token by calling the `registerFcmToken()` function on the `Mitter` object within the function which has the signature of `didRegisterForRemoteNotificationsWithDeviceToken` variable, like this:

```
InstanceID.instanceID().instanceID { (result, error) in
            if let error = error {
                print("Error fetching remote instange ID: \(error)")
            } else if let result = result {
                print("Remote instance ID token: \(result.token)")

                self.mitter.registerFcmToken(token: result.token) {
                    result in
                    switch result {
                    case .success(let deliveryEndpoint):
                        print("Endpoint is: \(deliveryEndpoint.serializedEndpoint)")
                    case .error:
                        print("Unable to register endpoint!")
                    }
                }
            }
        }
```

After that, you need to process incoming FCM messages by forwarding them to Mitter. Look for the function called `userNotificationCenter()` which has the variable named `willPresent` and then get the serialised data dictionary from the FCM notification dictionary, like this:

```
let messageString = userInfo["data"] as! String
```

Next, you need to convert this into a `MessagingPipelinePayload` object. This can be done by passing the serialised dictionary from the previous step, like this:

```
let messagingPipelinePayload = mitter.parseFcmMessage(data: messageString)
```

Now that you have the `MessagingPipelinePayload` object, you can check if the message is from Mitter by calling the function `isMitterMessage()` which returns `Bool`.

Next, you need to process the push message by passing the `MessagingPipelinePayload` object and hooking up the completion handlers, like this:

```
if mitter.isMitterMessage(messagingPipelinePayload) {
            let payload = mitter.processPushMessage(messagingPipelinePayload!)

            switch payload {
            case .NewMessagePayload(let message, let channelId):
                print("Received Message: \(message), for Channel: \(channelId)")
            default:
                print("Nothing to print!")
            }
        }
```

Here, `payload` is an enum which has various cases like `NewMessagePayload`, `NewChannelPayload`, etc.

> Do note, for FCM messages to work, you need to run the project in a physical iOS device.

 *Also, you need to include dataType as cloud-notification on any message that choose to send using a direct API call from Postman or any other REST client.*