Introduced in Batch 1.9, the Inbox API allows you to fetch and process notifications that this user has previously received, even if their device was offline.
You can then do anything you want with the data, such as making a "notification center", where the user can catch up with previous notifications in a list:
This screenshot is an example of what you can achieve with the Inbox API, but Batch does not include any UI.
The API gives you access to the entire notification, including its raw payload. It also lets you know if the notification has already been read, and allows you to mark one or all notifications as such.
Note: Just keep in mind that, once received/stored in the inbox your push notifications will remain for a 3 months period.
Let's get started!
The Inbox API has two modes:
In this mode, you can simply get the Inbox Fetcher with a context:
BatchInboxFetcher* inboxFetcher = [BatchInbox fetcher];
let inboxFetcher = BatchInbox.fetcher()
Since notifications can have sensitive content, you cannot get a user's notifications simply with their user identifier: Batch requires you to authenticate your request.
First, you will need your inbox secret key. You will find that in your dashboard, below your API Keys. It is unique for every app.
The authentification key is generated by computing a sha256 hmac hash of the API Key and the user identifier, using the secret as the key. Then, you have to encode the hash in a hexadecimal string.
For example, in PHP, that would be:
hash_hmac("sha256", APP_API_KEY + USER_ID, INBOX_SECRET)
For the API Key "abcdef", user identifier "paul", and secret of "foobar", the expected authentication key would be
Important note: This hash HAS to be computed on your server. If you bundle the inbox secret in your application to compute the hash, attackers will be able to extract it, and read the notifications of any of your users
Once you've got the authentification key from the server, you only have to give Batch the right user identifier and auth key tuple to get the Inbox Fetcher:
BatchInboxFetcher* inboxFetcher = [BatchInbox fetcherForUserIdentifier:@"paul" authenticationKey:@"796f1ab5d119d1b2eab8201e60335b56d1befff40c0f80263d64a169a8fd2e45"];
let inboxFetcher = BatchInbox.fetcher(forUserIdentifier: "paul", authenticationKey: "796f1ab5d119d1b2eab8201e60335b56d1befff40c0f80263d64a169a8fd2e45")
Now that you've got your fetcher instance, it's time to fetch notifications, and display them!
The inbox fetcher has several important methods and properties:
Note: BatchInboxFetcher and its methods are well documented in
BatchInbox.h. You can also use the web API Reference of BatchInboxFetcher to get detailed explanations about what every method does.
BatchInboxFetcher will not fetch any notification by default, so before trying to display anything, you will need to call
fetch methods take a block, which the SDK will call you back on either on failure, or success.
Success callbacks include information about the operation to operate on the data, but you can very well do with the global methods.
Note: The block callbacks are always called on the main thread
Once you've fetched notifications, you will end up with a list of BatchInboxNotificationContent objects.
These objects have everything you need to display these notifications:
Note: Just like when you get it using iOS' standard callbacks, the raw payload should be used carefully on keys you do not control:
- "aps" is considered private by Apple, and can change at any time. This has happened in the past, where the "alert" object got additional keys for new iOS features.
- "com.batch" is Batch's internal payload: You should not make any assumption about its content, nor depend on it. We reserve the right to change it at anytime, without warning.
- Standard parsing good practices apply: Make sure to check every cast and handle errors gracefully, and never assume anything about the payload's content.
Notifications can be marked as read in two ways:
markNotificationAsRead(notification)with the notification you want to mark as read.
In both cases, the notifications will be marked as read locally, but refreshing them might mark them as unread again, as the server might not have processed the request. These methods return quickly, and are thus safe to call on your UI thread.
Note that notifications that have been opened when received are automatically marked as read.
For more advanced usages, you can also change various aspects of the Inbox Fecther, such as: