Standard librarywebsubhubclients

PublisherClient

Client: PublisherClient

The HTTP based client for WebSub topic registration and deregistration, and notifying the hub of new updates.

Constructor

Initializes the websub:PublisherClient.

1websub:PublisherClient publisherClient = check new("https://sample.hub.com");
init (string url, *ClientConfiguration config)
  • url string

  • The URL to publish/notify updates

  • config *ClientConfiguration

  • The websubhub:ClientConfiguration for the underlying client or else ()

Remote Methods

registerTopic

Registers a topic in a Ballerina WebSub Hub to which the subscribers can subscribe and the publisher will publish updates.

deregisterTopic

Deregisters a topic in a Ballerina WebSub Hub.

publishUpdate

Publishes an update to a remote Ballerina WebSub Hub.

notifyUpdate

Notifies a remote WebSubHub from which an update is available to fetch for hubs that require publishing.

registerTopic 

function registerTopic(string topic) returns TopicRegistrationSuccess | TopicRegistrationError
Isolated Function
Remote Function

Registers a topic in a Ballerina WebSub Hub to which the subscribers can subscribe and the publisher will publish updates.

1websubhub:TopicRegistrationSuccess response = check publisherClient->registerTopic("http://websubpubtopic.com");

Parameters

  • topic string

    • The topic to register

Return Type

(TopicRegistrationSuccess | TopicRegistrationError)

A websubhub:TopicRegistrationError if an error occurred registering the topic or else websubhub:TopicRegistrationSuccess

deregisterTopic 

function deregisterTopic(string topic) returns TopicDeregistrationSuccess | TopicDeregistrationError
Isolated Function
Remote Function

Deregisters a topic in a Ballerina WebSub Hub.

1websubhub:TopicDeregistrationSuccess response = check publisherClient->deregisterTopic("http://websubpubtopic.com");

Parameters

  • topic string

    • The topic to deregister

Return Type

(TopicDeregistrationSuccess | TopicDeregistrationError)

A websubhub:TopicDeregistrationError if an error occurred un registering the topic or else websubhub:TopicDeregistrationSuccess

publishUpdate 

function publishUpdate(string topic, map<string> | string | xml | json | byte[ ] payload, string? contentType) returns Acknowledgement | UpdateMessageError
Isolated Function
Remote Function

Publishes an update to a remote Ballerina WebSub Hub.

1websubhub:Acknowledgement response = check publisherClient->publishUpdate("http://websubpubtopic.com",{"action": "publish",
2"mode": "remote-hub"});

Parameters

  • topic string

    • The topic for which the update occurred

  • contentType string? (default ())

    • The type of the update content to set as the ContentType header

Return Type

(Acknowledgement | UpdateMessageError)

A websubhub:UpdateMessageErrorif an error occurred with the update or else websubhub:Acknowledgement

notifyUpdate 

function notifyUpdate(string topic) returns Acknowledgement | UpdateMessageError
Isolated Function
Remote Function

Notifies a remote WebSubHub from which an update is available to fetch for hubs that require publishing.

1 websubhub:Acknowledgement|websubhub:UpdateMessageError response = check publisherClient->notifyUpdate("http://websubpubtopic.com");

Parameters

  • topic string

    • The topic for which the update occurred

Return Type

(Acknowledgement | UpdateMessageError)

A websubhub:UpdateMessageError if an error occurred with the notification or else websubhub:Acknowledgement