types.nope.IPubSubSystem

The default Publish and Subscribe System.

The System contains of publishers and subscribers which are linked using topics (based on strings).

• To add new publishers or subscribers use the function: register and provide the required options (see register)
• To add new subscriber you can use the function : registerSubscription which will receive a topic and a callback (see registerSubscription)
• After adding publishers or subscribers you can change the behavior using updateOptions (see updateOptions)
• To remove publishers or subscribers use unregister (see unregister)
• to emit data use emit (see emit)
• internally, if a subscriber / publisher is added, its options are changed or its removed, the pub sub system updates an matching structure. In the case you want to perform this manually execute updateMatching
• to check which publishers and subscribers are present, checkout the corresponding properties.
• You can subscribe to incremental changes using the eventEmitter onIncrementalDataChange
• If the pub-sub-system isnt needed any more dispose it!

The publisher might be observabes or eventEmitters.

The IPubSubSystem is implemented by the PubSubSystemBase-Class

The Behavior may differ based on the settings. Your are not able to change these options, after the instance has been created. (see IPubSubOptions for details) The Default of these options are settings are.

{
  mqttPatternBasedSubscriptions: true,
  forwardChildData: true,
  forwardParentData: true,
  matchTopicsWithoutWildcards: true,
}

// Describe the required Test:
let pubSubSystem = new PubSubSystemBase({
  generateEmitterType: function () {
    return new NopeEventEmitter() as INopeEventEmitter;
  },
});

// Create a Publisher for the system:
let publisher: INopeEventEmitter = new NopeEventEmitter();

pubSubSystem.register(publisher, {
  mode: "publish",
  schema: {},
  topic: "this/is/a/test",
});

// Create a Subscriber
let subscriber: INopeEventEmitter = new NopeEventEmitter();

subscriber = pubSubSystem.register(subscriber, {
  mode: "subscribe",
  schema: {},
  topic: "this/#",
});

subscriber.subscribe(console.log);
publisher.emit("Hello World!"); // Logs the following => "Hello World!", {...}

Author

M.Karkowski

Export

• IPubSubSystem

  ↳ IDataPubSubSystem

• PubSubSystem

Readonly emitters: Object

List all known Emitters in the System.

Readonly onIncrementalDataChange: INopeEventEmitter<IIncrementalChange, IIncrementalChange, IIncrementalChange, IEventAdditionalData>

An observable which holds the incremental data change. this will be triggered, if the an emitter (publisher) changes its data. Contains only the last emitted data and the topic

// Describe the required Test:
let pubSubSystem = new PubSubSystemBase({
  generateEmitterType: function () {
    return new NopeEventEmitter() as INopeEventEmitter;
  },
});

// Create a Publisher for the system:
let publisher: INopeEventEmitter = new NopeEventEmitter();

pubSubSystem.register(publisher, {
  mode: "publish",
  schema: {},
  topic: "this/is/a/test",
});

pubSubSystem.onIncrementalDataChange.subscribe(console.log);
publisher.emit("Hello World!"); // Logs the following => {path: "this/is/a/test", data: "Hello World!"}

Author

M.Karkowski

Memberof

IPubSubSystem

Readonly options: IPubSubOptions

Options which describe the Behavior

Author

M.Karkowski

Memberof

IPubSubSystem

Readonly publishers: IMapBasedMergeData<O, IPubSubEmitterOptions<AD>, O, string>

List containing all publishers.

Author

M.Karkowski

Memberof

IPubSubSystem

Readonly subscriptions: IMapBasedMergeData<O, IPubSubEmitterOptions<AD>, O, string>

List, containing all subscribers.

Author

M.Karkowski

Memberof

IPubSubSystem

dispose(): void

Disposes the Pub-Sub-System.

Author

M.Karkowski

Memberof

IPubSubSystem

void

emit(path, data, options?): void

Emits an Events and all subscribes, where the pattern matches will be informed

Author

M.Karkowski

Memberof

IPubSubSystem

void

register(emitter, options): O

Function to register an Observable. Please define the Options, to decide whether the data of the observable should be published or subscribed.

Author

M.Karkowski

Memberof

IPubSubSystem

O

{O}

registerSubscription<T>(path, subscription): INopeObserver

A Helper, that allows the user to subscribe to changes. Therfore he must transmit

Author

M.Karkowski

Memberof

IPubSubSystem

INopeObserver

{INopeObserver}

toDescription(): Object

Lists all publishers and subscribers of the system.

Object

unregister(emitter): boolean

Removes an observable of the Pub-Sub-System.

Author

M.Karkowski

Memberof

IPubSubSystem

boolean

{boolean}

updateMatching(): void

Helper to manually Trigger an update of the Matching. This will update subscribers and publishers and link them. Normally this is not necessary.

This will build an internal linking (based on the settings) between publishers and subscribers.

Author

M.Karkowski

Memberof

IPubSubSystem

void

updateOptions(emitter, options): void

Function to update the options and there by the topics of an observable.

Author

M.Karkowski

Memberof

IPubSubSystem

void