Application

Before you start building your chat, it is important to understand that your Sendbird application has core functionalities to maintain chat service stability and basic features for application management. This page presents how you can use a Sendbird application in your app to ensure optimal performance.

To prevent abnormal user activity, a Sendbird application has the following limits on the number of messages per second which a user can send and an open channel can display.

You can change the default limit settings by contacting our sales team.

For a seamless chat experience, our Chat SDK manages connections to Sendbird server at an application-wide level. The following table shows how connections between a client app's SBDMain instance and our server are managed. This is according to the states of iOS devices where your native app is working on.

One user ID can make connections to up to 30 devices or browsers simultaneously. All connections from one user ID are counted and reflected in your application’s concurrent connections. Since they are used to calculate your service billing, caution is advised.

By creating a SBDApplicationUserListQuery instance and using it, you can retrieve a list of all or certain users in your Sendbird application. The loadNextPageWithCompletionHandler: method returns a list of SBDUser objects which contain information on users within the application.

// Retrieving all users.
let listQuery = SBDMain.createApplicationUserListQuery()

listQuery?.loadNextPage(completionHandler: { (users, error) in
    guard error == nil else {
        // Handle error.
    }

    // A list of users is successfully retrieved.
    // Through the "users" parameter of the callback method,
    // you can access the data of each user from the result list that Sendbird server has passed to the callback method.
    ...
})

With the several different types of filters the SBDApplicationUserListQuery instance provides, you can retrieve a list of specific users that match the set values in the filters. Currently the SBDApplicationUserListQuery instance supports the following three filters:

Note: We recommend you set the maximum number of user IDs to 250 in the userIdsFilter. If exceeded, your query may receive an HTTP 414 error indicating that the submitted request data is longer than Sendbird server is willing to interpret.

// Retrieving certain users using the UserID filter.
let listQuery = SBDMain.createApplicationUserListQuery()
listQuery?.userIdsFilter = ["Harry", "Jay", "Jin"]

listQuery?.loadNextPage(completionHandler: { (users, error) in
    guard error == nil else {
        // Handle error.
    }

    // A list of matching users is successfully retrieved.
    ...
})

// Retrieving certain users using the MetaDataKey filter.
let listQuery = SBDMain.createApplicationUserListQuery()
listQuery?.metaDataFilterWithKey = ["hobby", ["movie", "book", "exercise"]]

listQuery?.loadNextPage(completionHandler: { (users, error) in
    guard error == nil else {
        // Handle error.
    }

    // A list of matching users is successfully retrieved.
    ...
})

A user can block specific users to stop receiving further messages from them in 1-to-1 group channels and notifications of their messages in 1-to-N group channels. You can choose whether or not users can view which users they have blocked in the channel UI.

A Sendbird application provides two blocking options: including or excluding blocked users when sending invitations and turning on/off push notifications from blocked users. The previous block modes are now deprecated and only supported for customers who have been using them from before.

• Including or excluding blocked users when sending invitations: determines whether or not to automatically filter out blocked users when a user invites a group of users to a new group channel. The value of this option can be adjusted only from our side before integrating your Sendbird application to an app. If you want to change the value, contact our sales team for further assistance. (Default: including)
• Turning on/off push notifications from blocked users: determines whether or not to send push notifications to a user for the messages that blocked users sent in a specific 1-to-N group channel where they are members together. The value of this option can be set individually by channel. If you want to use this option, contact our sales team for further assistance. (Default: off)

You can allow a user to block and unblock other users by implementing the following code to your client app.

// Blocking a user.
SBDMain.blockUser(USER, completionHandler: { (blockedUser, error) in
    guard error == nil else {
        // Handle error.
    }

    // The blocked user can be retrieved through the "blockedUser" parameter of the callback method.
    ...
})

// Unblocking a user.
SBDMain.unblockUser(USER, completionHandler: { (error) in
    guard error == nil else {
        // Handle error.
    }

    // The user is successfully unblocked.
    ...
})

Note: You can use the blockUserId:completionHandler: and unblockUserId:completionHandler: methods, instead of the blockUser:completionHandler: and unblockUser:completionHandler:, as they have the same functionalities.

Using the SBDBlockedUserListQuery's loadNextPageWithCompletionHandler: method, you can retrieve a list of all or certain users who are blocked by a specific user in your Sendbird application. The method returns a list of SBDUser objects which contain information on blocked users.

// Retrieving all blocked users.
let listQuery = SBDMain.createBlockedUserListQuery()

listQuery?.loadNextPage(completionHandler: { (users, error) in
    guard error == nil else {
        // Handle error.
    }

    // A list of blocked users is successfully retrieved.
    // Through the "users" parameter of the callback method,
    // you can access the data of each blocked user from the result list that Sendbird server has passed to the callback method.
    ...
})

With the BlockedUserListQuery's UserID filter, you can retrieve a list of the blocked users that match the user IDs in the filter.

// Retrieving certain blocked users using the UserID filter.
let listQuery = SBDMain.createBlockedUserListQuery()
listQuery?.userIdsFilter = ["John", "Daniel", "Jeff"]

listQuery?.loadNextPage(completionHandler: { (users, error) in
    guard error == nil else {
        // Handle error.
    }

    // A list of matching users is successfully retrieved.
    ...
})

You can check if a certain user is currently connected to Sendbird server.

let listQuery = SBDMain.createApplicationUserListQuery()
listQuery?.userIdsFilter = ["Jeff"]

listQuery?.loadNextPage(completionHandler: { (users, error) in
    guard error == nil else {
        // Handle error.
    }

    // users[0] = 'Jeff'
    if users?[0].connectionStatus == SBDUserConnectionStatus.online {
        // 'Jeff' is currently online.
        // SBDUserConnectionStatus consists of online, offline, and nonAvailable.
        ...
    }
})