Channel Namespace

ChannelMessage interface

Every message delivered to a subscribe callback is wrapped in a ChannelMessage<D> envelope.

Definition

export interface ChannelMessage<D = ChannelMessageData> {
    address: {
        boundary: string; // Scope boundary of the address (e.g. 'WORLD')
        category: string; // Push category of the address (e.g. 'RUN')
        key: string;      // Scope key for the address
    };
    sender: {
        type: string; // Sender type, e.g. 'USER' or 'SYSTEM'
        key: string;  // Sender key
    };
    content: D;      // The published payload
    date: string;    // ISO 8601 timestamp of when the message was sent
    type: string;    // Message type/category
}

Properties

• address.boundary: The scope boundary of the address (e.g. WORLD).
• address.category: The push category of the address (e.g. RUN).
• address.key: The scope key for the address (e.g. your world key when boundary is WORLD).
• sender.type: The sender type — typically USER or SYSTEM.
• sender.key: The unique key identifying the sender.
• content: The published payload, typed as D.
• date: An ISO 8601 timestamp string for when the message was sent.
• type: The message type/category.

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ChannelScope interface

The ChannelScope interface describes the scope of a push channel. It extends the GenericScope interface.

Properties

• Inherits all properties of GenericScope.
• pushCategory (string): Identifies the channel type. For details, see PUSH_CATEGORY enum.

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ChannelMessageData type

Default type for the content field of ChannelMessage interface.

Override by passing a type argument to Channel<MyType> class to get end-to-end typing on both publish and subscribe.

Definition

export type ChannelMessageData = unknown;

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Channel class

Implements push channels in Epicenter using CometD.

learn more

For a detailed description of the class and its methods, read Channel class.