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.
Note : User metadata, channel metadata, and channel metacounter can each have up to 5 key-value items. The key’s length must be no larger than 128 characters. For user metadata and channel metadata, the value must be a
Stringand its length must be no larger than 190 characters. For channel metacounter, the value must be anInteger.
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 Map<String, String> and it can be stored into a User object.
To store a user metadata into a User object, add key-value items after creating a Map<String, String>, and pass it as an argument to a parameter when calling the createMetaData() method. You can put multiple key-value items in the map.
User user = SendBird.getCurrentUser();
HashMap<String, String> data = new HashMap<String, String>();
data.put("key1", "value1");
data.put("key2", "value2");
user.createMetaData(data, new User.MetaDataHandler() {
@Override
public void onResult(Map<String, String> map, SendBirdException e) {
if (e != null) {
// 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.
User user = SendBird.getCurrentUser();
HashMap<String, String> data = new HashMap<String, String>();
data.put("key1", "valueToUpdate1");
data.put("key2", "valueToUpdate2");
user.updateMetaData(data, new User.MetaDataHandler() {
@Override
public void onResult(Map<String, String> map, SendBirdException e) {
if (e != null) {
// Handle error.
}
...
}
});
You can retrieve user metadata by creating a List of keys to retrieve and passing it as an argument to a parameter in the getMetaData() method. A Map<String, String> will return key-value items through the onResult() method.
List<String> keys = new ArrayList<String>();
keys.add("key1");
keys.add("key2");
user.getMetaData(keys, new User.MetaDataHandler() {
@Override
public void onResult(Map<String, String> map, SendBirdException e) {
if (e != null) {
// Handle error.
}
...
}
});
You can delete a user metadata as below.
User user = SendBird.getCurrentUser();
user.deleteMetaData("key1", new User.MetaDataHandler() {
@Override
public void onResult(SendBirdException e) {
if (e != null) {
// 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 Map<String, String> and it can be stored into a Channel object.
To store a channel metadata into a Channel object, add key-value items after creating a Map<String, String>, and pass it as an argument to a parameter when calling the createMetaData() method. You can put multiple key-value items in the map.
HashMap<String, String> data = new HashMap<String, String>();
data.put("key1", "value1");
data.put("key2", "value2");
channel.createMetaData(data, new BaseChannel.MetaDataHandler() {
@Override
public void onResult(Map<String, String> map, SendBirdException e) {
if (e != null) {
// 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.
HashMap<String, String> data = new HashMap<String, String>();
data.put("key1", "valueToUpdate1"); // Update an existing item with a new value.
data.put("key2", "valueToUpdate2"); // Update an existing item with a new value.
data.put("key3", "valueToAdd3"); // Add a new key-value item.
channel.updateMetaData(data, new BaseChannel.MetaDataHandler() {
@Override
public void onResult(Map<String, String> map, SendBirdException e) {
if (e != null) {
// Handle error.
}
...
}
});
You can retrieve channel metadata by creating a List of keys to retrieve and passing it as an argument to a parameter in the getMetaData() method. A Map<String, String> will return key-value items through the onResult() method.
List<String> keys = new ArrayList<String>();
keys.add("key1");
keys.add("key2");
channel.getMetaData(keys, new BaseChannel.MetaDataHandler() {
@Override
public void onResult(Map<String, String> map, SendBirdException e) {
if (e != null) {
// 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 cached metadata through the cachedMetaData() method without having to query the server.
final Map<String, String>() cachedMetaData = channel.getCachedMetaData();
final String value = cachedMetaData.get(key); // The key should be string.
You can delete a channel metadata as below.
channel.deleteMetaData("key1", new BaseChannel.MetaDataHandler() {
@Override
public void onResult(SendBirdException e) {
if (e != null) {
// 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 Map<String, Integer> and it can be stored into a Channel 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 channel metacounter into a Channel object, add key-value items after creating a Map<String, Integer>, and pass it as an argument to a parameter when calling the createMetaCounter() method. You can put multiple key-value items in the map.
HashMap<String, Integer> counters = new HashMap<String, Integer>();
counters.put("key1", 1);
counters.put("key2", 2);
channel.createMetaCounters(counters, new BaseChannel.MetaCounterHandler() {
@Override
public void onResult(Map<String, Integer> map, SendBirdException e) {
if (e != null) {
// 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.
HashMap<String, Integer> data = new HashMap<String, Integer>();
data.put("key1", 3); // Update 1 to 3
data.put("key2", 4); // Update 2 to 4
data.put("key3", 0); // Add a new key-value item.
channel.updateMetaCounters(data, new BaseChannel.MetaCounterHandler() {
@Override
public void onResult(Map<String, Integer> map, SendBirdException e) {
if (e != null) {
// Handle error.
}
...
}
});
You can increase values in a channel metacounter by passing a Map of keys to increase as an argument to a parameter in the increaseMetaCounters() method. The values of corresponding keys in the metacounter will be incremented by the number you’ve specified.
HashMap<String, Integer> counters = new HashMap<String, Integer>();
counters.put("key1", 2); // Increase by 2.
counters.put("key2", 3); // Increase by 3.
channel.increaseMetaCounters(counters, new BaseChannel.MetaCounterHandler() {
@Override
public void onResult(Map<String, Integer> map, SendBirdException e) {
if (e != null) {
// Handle error.
}
...
}
});
You can decrease values in a channel metacounter by passing a Map of keys to decrease as an argument to a parameter in the decreaseMetaCounters() method. The values of corresponding keys in the metacounter will be decremented by the number you’ve specified.
HashMap<String, Integer> counters = new HashMap<String, Integer>();
counters.put("key1", 3); // Decrease by 3.
counters.put("key2", 4); // Decrease by 4.
channel.decreaseMetaCounters(counters, new BaseChannel.MetaCounterHandler() {
@Override
public void onResult(Map<String, Integer> map, SendBirdException e) {
if (e != null) {
// Handle error.
}
...
}
});
You can retrieve channel metacounter by creating a List of keys to retreive and passing it as an argument to a parameter in the getMetaCounters() method. A Map<String, Integer> will return through the onResult() method with corresponding key-value items.
List<String> keys = new ArrayList<String>();
keys.add("key1");
keys.add("key2");
channel.getMetaCounters(keys, new BaseChannel.MetaCounterHandler() {
@Override
public void onResult(Map<String, Integer> map, SendBirdException e) {
if (e != null) {
// Handle error.
}
...
}
});
You can delete a channel metacounter as below.
channel.deleteMetaCounters("key1", new BaseChannel.MetaCounterHandler() {
@Override
public void onResult(SendBirdException e) {
if (e != null) {
// Handle error.
}
...
}
});