User & channel metadata

With metadata and metacounter which consist of key-value items, you can store additional information to users and channels. This page explains how to manage user metadata, channel metadata, and channel metacounter.

The key's length must be no longer than 128 characters. For user metadata and channel metadata, the value must be a String and its length must be no longer than 190 characters. For channel metacounter, the value must be an Integer. For user metadata, it can have up to five key-value items.

Note: By default, the Allow retrieving user list and Allow updating user metadata options are turned on which means that any user can retrieve a list of users and their metadata as well as alter other users' nicknames and their metadata within your application. This may grant access to unwanted data or operations, leading to potential security concerns. To manage your access control settings, you can turn on or off each option in Settings > Application > Security > Access control list on Sendbird Dashboard.

You can store additional information to users such as phone number, email or a long description of a user with user metadata, which can be fetched or rendered into the UI. A user metadata is a NSDictionary<NSString *, NSString *> and it can be stored into a SBDUser object.

To store a user metadata into a SBDUser object, add key-value items after creating a NSDictionary<NSString *, NSString *>, and pass it as an argument to a parameter when calling the createMetaData:completionHandler: method. You can put multiple key-value items in the dictionary.

let user = SBDMain.getCurrentUser()!

let data = [
    "key1": "value1",
    "key2": "value2"
]

user.createMetaData(data, completionHandler: { (metaData, error) in
    guard error == nil else {
        // Handle error.
    }


})

The procedure to update a user metadata is the same as creating a user metadata. Values of existing keys will be updated and values of new keys will be added.

let user = SBDMain.getCurrentUser()!

let data = [
    "key1": "valueToUpdate1",
    "key2": "valueToUpdate2"
]

user.updateMetaData(data, completionHandler: { (metaData, error) in
    guard error == nil else {
        // Handle error.
    }


})

You can retrieve user metadata by reading the metadata property of a SBDUser object.

let user = SBDMain.getCurrentUser()!
let metaData = user.metaData

You can delete a user metadata as below.

let user = SBDMain.getCurrentUser()!

user.deleteMetaData(withKey: "key1", completionHandler: { (error) in
    guard error == nil else {
        // Handle error.
    }

    ...
})

You can store additional information to channels such as background color or a long description of a channel with channel metadata, which can be fetched or rendered into the UI. A channel metadata is a NSDictionary<NSString *, NSString *> and it can be stored into a SBDOpenChannel or a SBDGroupChannel object.

To store a channel metadata into a channel, add key-value items after creating a NSDictionary<NSString *, NSString *>, and pass it as an argument to a parameter when calling the createMetaData:completionHandler: method. You can put multiple key-value items in the dictionary.

SBDOpenChannel.getWithUrl(CHANNEL_URL, completionHandler: { (channel, error) in
    let newMetaData: NSDictionary = [
        "key1": "value1",
        "key2": "value2"
    ]

    channel?.createMetaData(newMetaData, completionHandler: { (metaData, error) in
        guard error == nil else {
            // Handle error.
            }


    })
})

The procedure to update a channel metadata is the same as creating a channel metadata. Values of existing keys will be updated and values of new keys will be added.

SBDOpenChannel.getWithUrl(CHANNEL_URL, completionHandler: { (channel, error) in
    let metaDataToUpdate: NSDictionary = [
        "key1": "valueToUpdate1",   // Update an existing item with a new value.
        "key2": "valueToUpdate2",   // Update an existing item with a new value.
        "key3": "valueToAdd3"       // Add a new key-value item.
    ]

    channel?.updateMetaData(metaDataUpUpdate, completionHandler: { (metaData, error) in
        guard error == nil else {
            // Handle error.
            }


    })
})

You can retrieve channel metadata by creating a NSArray of keys to retrieve and passing it as an argument to a parameter in the getMetaDataWithKeys:completionHandler: method. A NSDictionary<NSString *,NSObject *> will return through the completionHandler with corresponding key-value items.

SBDOpenChannel.getWithUrl(CHANNEL_URL, completionHandler: { (channel, error) in
    let keys : NSArray = ["key1", "key2"]

    channel?.getMetaData(withKeys: keys, completionHandler: { (metaData, error) in
        guard error == nil else {
            // Handle error.
        }


    })
})

When Sendbird Chat SDK detects any of the create, read, update, and delete operations on the channel metadata, the SDK caches the metadata. The cached metadata is also updated whenever a channel list is fetched.

You can retrieve the metadata through the getCachedMetaData() method without having to query the server.

let cachedMetaData = channel.getCachedMetaData()
let value = cachedMetaData[key] // The key should be string.

You can delete a channel metadata as below.

channel.deleteMetaData(withKey: "key1", completionHandler: { (error) in
    guard error == nil else {
        // Handle error.
    }

    ...
})

You can store additional information to channels such as the tracking number of likes with channel metacounter, which can be fetched or rendered into the UI. A channel metacounter is a NSDictionary<NSString *, NSNumber *> and it can be stored into a SBDOpenChannel or a SBDGroupChannel object.

Note : A channel metacounter is primarily used to track and update discrete indicators in a channel. Use channel metacounter instead of channel metadata when you need an integer with atomic increasing and decreasing operations.

To store a metacounter into a channel, add key-value items after creating a NSDictionary<NSString *, NSNumber *>, and pass it as an argument to a parameter when calling the createMetaCounters:completionHandler: method. You can put multiple key-value items in the dictionary.

SBDOpenChannel.getWithUrl(CHANNEL_URL, completionHandler: { (channel, error) in
    let newMetaCounters: NSDictionary = [
        "key1": 1,
        "key2": 2
    ]

    channel?.createMetaCounters(newMetaCounters, completionHandler: { (metaCounters, error) in
        guard error == nil else {
            // Handle error.
        }


    })
})

The procedure to update a channel metacounter is the same as creating a channel metacounter. Values of existing keys will be updated and values of new keys will be added.

SBDOpenChannel.getWithUrl(CHANNEL_URL, completionHandler: { (channel, error) in
    let metaCountersToUpdate: NSDictionary = [
        "key1": 3,  // Update 1 to 3.
        "key2": 4,  // Update 2 to 4.
        "key3": 0   // Add a new key-value item.
    ]

    channel?.updateMetaCounters(metaCountersToUpdate, completionHandler: { (metaCounters, error) in
        guard error == nil else {
            // Handle error.
        }


    })
})

You can increase values in a channel metacounter by passing a NSDictionary<NSString *, NSNumber *> of items to increase as an argument to a parameter in the increaseMetaCounters:completionHandler: method. The values of corresponding keys in the metacounter will be incremented by the number you’ve specified.

SBDOpenChannel.getWithUrl(CHANNEL_URL, completionHandler: { (channel, error) in
    let deltaMetaCounters: NSDictionary = [
        "key1": 2, // Increase by 2.
        "key2": 3  // Increase by 3.
    ]

    channel?.increaseMetaCounters(deltaMetaCounters, completionHandler: { (metaCounters, error) in
        guard error == nil else {
            // Handle error.
        }


    })
})

You can decrease values in a channel metacounter by passing a NSDictionary<NSString *, NSNumber *> of items to decrease as an argument to a parameter in the decreaseMetaCounters:completionHandler: method. The values of corresponding keys in the metacounter will be decremented by the number you’ve specified.

SBDOpenChannel.getWithUrl(CHANNEL_URL, completionHandler: { (channel, error) in
    let deltaMetaCounters: NSDictionary = [
        "key1": 3, // Decrease by 3.
        "key2": 4  // Decrease by 4.
    ]

    channel?.decreaseMetaCounters(deltaMetaCounters, completionHandler: { (metaCounters, error) in
        guard error == nil else {
            // Handle error.
        }


    })
})

You can retrieve channel metacounter by creating a NSArray of keys to retrieve and passing it as an argument to a parameter in the getMetaCountersWithKeys:completionHandler: method. A NSDictionary<NSString *,NSNumber *> will return through the completionHandler with corresponding key-value items.

SBDOpenChannel.getWithUrl(CHANNEL_URL, completionHandler: { (channel, error) in
    let keys : NSArray = ["key1", "key2"]

    channel?.getMetaCounters(withKeys: keys, completionHandler: { (metaCounters, error) in
        guard error == nil else {
            // Handle error.
        }


    })
})

The process for deleting a metacounter is as simple as creating one.

channel.deleteMetaCounters(withKey: "key1", completionHandler: { (error) in
    guard error == nil else {
        // Handle error.
    }

    ...
})