Configuration API for PubNub Dart SDK
Dart complete API reference for building Realtime Applications on PubNub, including basic usage and sample code.
Configuration
Dart SDK allows you to create various configurations for different subscribe keys. Each configuration is stored in a Keyset
object.
You can use a KeysetStore
to store your Keyset
s but make sure that individual Keyset
names are unique and note that only one can be the default.
Method(s)
Keyset(
{String subscribeKey,
String publishKey,
String secretKey,
String authKey,
UserId userId}
)
The Keyset
object has the following properties:
Properties | Type | Required | Default | Description |
---|---|---|---|---|
subscribeKey | String | Yes | subscribeKey from the Admin Portal. | |
publishKey | String | Optional | publishKey from the Admin Portal (only required if publishing). | |
secretKey | String | Optional | secretKey used for administrative tasks. | |
authKey | String | Optional | If Access Manager is enabled, all communications to and from PubNub are encrypted. | |
userId | String | Yes | userId to use. You should set a unique identifier for the user or the device that connects to PubNub.It's a UTF-8 encoded string of up to 92 alphanumeric characters. If you don't set theuserId , you won't be able to connect to PubNub. | |
cipherKey | String | This way of setting this parameter is deprecated, pass it to crypto instead. | ||
UUID | String | This parameter is deprecated, use userId instead.UUID to use. You should set a unique UUID to identify the user or the device that connects to PubNub.If you don't set the UUID , you won't be able to connect to PubNub. |
Basic Usage
Required UserId
Always set the userId
to uniquely identify the user or device that connects to PubNub. This userId
should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the userId
, you won't be able to connect to PubNub.
final myKeyset = Keyset(
subscribeKey: 'subscribeKey',
publishKey: 'publishKey',
userId: UserId('yourUniqueUserId'));
Initialization
Add PubNub to your project using one of the procedures defined in Getting Started.
Description
To use the Dart SDK, instantiate the PubNub
class with a default Keyset
. The default Keyset
is used any time a specific Keyset
isn't explicitly passed into a method. All methods that you call try to obtain the keyset according to these rules:
- The
keyset
parameter has the highest priority. - If
keyset
is null, the method tries to get a keyset from theusing
parameter. - If
using
is null, the method tries to get the default keyset. - If the default keyset isn't defined, the method throws an error.
Methods
To initialize PubNub, you can use the following constructor in the Dart SDK:
PubNub(
{Keyset defaultKeyset,
INetworkingModule networking,
IParserModule parser,
ICryptoModule crypto}
)
The PubNub
constructor takes the following arguments:
Properties | Type | Required | Default | Description |
---|---|---|---|---|
defaultKeyset | Keyset | Yes | The default keyset to use. | |
networking | INetworkingModule | Optional | NetworkingModule | The default networking module to use. Inside this module, you can configure a custom origin and whether to use SSL. |
parser | IParserModule | Optional | ParserModule | The default parser module to use for parsing data. |
crypto | ICryptoModule | Optional | CryptoModule | The cryptography module used for encryption and decryption of messages and files. Takes the cipherKey parameter as argument. For more information, refer to the cryptoModule section. |
cryptoModule
cryptoModule
provides encrypt/decrypt functionality for messages and files. From the 4.2.4 release on, you can configure how the actual encryption/decryption algorithms work.
Each PubNub SDK is bundled with two ways of encryption: the legacy encryption with 128-bit cipher key entropy and the recommended 256-bit AES-CBC encryption. For more general information on how encryption works, refer to the Message Encryption and File Encryption sections.
If you do not explicitly set the cryptoModule
in your app and have the cipherKey
param set in PubNub config, the client defaults to using the legacy encryption.
Legacy encryption with 128-bit cipher key entropy
You don't have to change your encryption configuration if you want to keep using the legacy encryption. If you want to use the recommended 256-bit AES-CBC encryption, you must explicitly set that in PubNub config.
cryptoModule
configuration
To configure the cryptoModule
to encrypt all messages/files, you can use the following methods in the Dart SDK:
// encrypts using 256-bit AES-CBC cipher (recommended)
// decrypts data encrypted with the legacy and the 256-bit AES-CBC ciphers
var cryptoModule = CryptoModule.aescbcCryptoModule(CipherKey.fromUtf8('enigma'));
// encrypts with 128-bit cipher key entropy (legacy)
// decrypts data encrypted with the legacy and the 256-bit AES-CBC ciphers
var cryptoModule = CryptoModule.legacyCryptoModule(CipherKey.fromUtf8('enigma'));
// partial encryption
// create cryptoModule
var cryptoModule = CryptoModule.aesCbcCryptoModule(CipherKey.fromUtf8('abcd'));
// encrypt normal message
var encrypted = cryptoModule.encrypt('Hello'.codeUnits);
show all 17 linesYour client can decrypt content encrypted using either of the modules. This way, you can interact with historical messages or messages sent from older clients while encoding new messages using the more secure 256-bit AES-CBC cipher.
Older SDK versions
Apps built using the SDK versions lower than 4.2.4 will not be able to decrypt data encrypted using the 256-bit AES-CBC cipher. Make sure to update your clients or encrypt data using the legacy algorithm.
Basic Usage
final pubnub = PubNub(defaultKeyset: myKeyset);
Returns
Initialization returns the PubNub instance for invoking PubNub APIs like publish()
, subscribe()
, etc.
Other Examples
Initialize a non-secure client
final pubnub =
PubNub(
defaultKeyset: myKeyset,
networking: NetworkingModule(ssl: false));
Initialization for a Read-Only client
final pubnub = PubNub(
defaultKeyset:
Keyset(subscribeKey: 'mysubscribeKey',
userId: UserId('myUniqueUserId')));
Initialization with custom origin
If your use-case requires to route traffic through custom domain instead of the default one, you can set up your SDK such that all your traffic is routed through example.com
:
final pubnub = PubNub(
defaultKeyset: myKeyset,
networking: NetworkingModule(origin: 'example.com', ssl: true),
);
Initializing with SSL Enabled
This example demonstrates how to enable PubNub Transport Layer Encryption with SSL
. Just initialize the client with ssl
set to true
. The hard work is done, now the PubNub API takes care of the rest. Just subscribe and publish as usual and you are good to go.
final pubnub =
PubNub(
defaultKeyset: myKeyset,
networking: NetworkingModule(ssl: true));
Initializing with Access Manager
Requires Access Manager add-on
This method requires that the Access Manager add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.
Secure your secretKey
Anyone with the secretKey
can grant and revoke permissions to your app. Never let your secretKey
be discovered, and to only exchange it / deliver it securely. Only use the secretKey
on secure server-side platforms.
When you init with secretKey
, you get root permissions for the Access Manager. With this feature you don't have to grant access to your servers to access channel data. The servers get all access on all channels.
For applications that will administer Access Manager permissions, the API is initialized with the secretKey
as in the following example:
final pubnub = PubNub(
defaultKeyset: Keyset(
subscribeKey: 'mySubscribeKey',
secretKey: 'my_secretkey',
userId: UserId('myUniqueUserId')));
Now that the pubnub
object is instantiated the client will be able to access the Access Manager functions. The pubnub
object will use the secretKey to sign all Access Manager messages to the PubNub Network.
Event Listeners
You can be notified of connectivity status, message, and presence notifications via the listeners. For the listeners to work, you must have a Subscription
. For more information, refer to the Subscription section.
Listeners
The following listeners are available:
message
signal
objects
messageAction
file
subscription.messages.listen((envelope) {
switch (envelope.messageType) {
case MessageType.normal:
print('${envelope.publishedBy} sent a message: ${envelope.content}');
print('${envelope.channel}'); //to display the channel that message was sent on
print('${envelope.publishedAt}'); // to display timetoken of the message received
print('${envelope.content}'); // to display content of the message
print('${envelope.uuid}'); // to display the uuid of the sender
break;
case MessageType.signal:
print('${envelope.publishedBy} sent a signal message: ${envelope.content}');
print('${envelope.channel}'); //to display the channel that message was sent on
print('${envelope.publishedAt}'); // to display timetoken of the message received
print('${envelope.content}'); // to display content of the message
print('${envelope.uuid}'); // to display the uuid of the sender
show all 55 linesuserID
These functions are used to set/get a user ID on the fly.
Methods
To set/get userId
you can use the following method(s) in the Dart SDK:
var myKeyset =
Keyset(subscribeKey: 'subscribeKey', userId: UserId('myUniqueUserId'));
Parameter | Type | Required | Default | Description |
---|---|---|---|---|
userId | String | Yes | User ID to be used as a device identifier. |
Basic Usage
Required UserId
Always set the userId
to uniquely identify the user or device that connects to PubNub. This userId
should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the userId
, you won't be able to connect to PubNub.
final pubnub = PubNub(
defaultKeyset: Keyset(
subscribeKey: 'mySubscribeKey',
userId: UserId('myUniqueUserId')));
// to know which userId is set
var userId = pubnub.keysets.defaultKeyset.userId;
Authentication Key
Setter and getter for users' authentication key.
Method(s)
var myKeyset = Keyset(
subscribeKey: 'subscribeKey',
authKey: 'myAuthkey',
userId: UserId('myUniqueUserId'));
Parameter | Type | Required | Description |
---|---|---|---|
authKey | String | Yes | If Access Manager is utilized, client will use this authKey in all restricted requests. |
Basic Usage
final pubnub = PubNub(
defaultKeyset: Keyset(
subscribeKey: 'mySubscribeKey',
authKey: 'myAuthkey',
userId: UserId('myUniqueUserId')));
Filter Expression
Requires Stream Controller add-on
This method requires that the Stream Controller add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.
Stream filtering allows a subscriber to apply a filter to only receive messages that satisfy the conditions of the filter. The message filter is set by the subscribing client(s) but it's applied on the server side thus preventing unwanted messages (those that do not meet the conditions of the filter) from reaching the subscriber.
To set or get message filters, you can use the following method. To learn more about filtering, refer to the Publish Messages documentation.
Method(s)
// to know which filter expression is set
var filterExpression = pubnub.keysets.defaultKeyset.filterExpression;
Parameter | Type | Required | Description |
---|---|---|---|
filterExpression | String | Yes | PSV2 feature to subscribe with a custom filter expression. |
Basic Usage
var myKeyset =
Keyset(subscribeKey: 'subscribeKey', userId: UserId('myUniqueUserId'))
..filterExpression = 'such=wow';
final pubnub = PubNub(defaultKeyset: myKeyset);
Handling Disconnects
The client may disconnect due to unpredictable network conditions. By default, the client reconnects exponentially for subscribe connections only.
For more information, refer to Reconnection Policy.
You can configure automatic reconnection as follows:
var pubnub = PubNub(
networking:
NetworkingModule(retryPolicy: RetryPolicy.exponential(maxRetries: 10)));
Available retry policies include:
RetryPolicy.exponential({int? maxRetries, int? maximumDelay});
RetryPolicy.linear({int? backoff, int? maxRetries, int? maximumDelay})
Argument | Type | Description |
---|---|---|
maximumDelay | int | Maximum amount of milliseconds to wait until retry is executed. |
backoff | int | Backoff amount in milliseconds. |
maxRetries | int | Number of max retries. |