IDelegate<TFunc>

Interface

A subscription. Used to subscribe callbacks to events.

Type parameters

Name	Type
TFunc	extends Function

Properties

fire

Fire (Evoke)

Type

​TFunc

Methods

subscribe

Subscribe a callback function to this event. Subscribed callbacks are called when the event fires.

Example

// Log 'Series data loaded!' to the console the next time the data loaded event fires and then unsubscribe automatically.
seriesApi.onDataLoaded().subscribe(null, () => { console.log('Series data loaded!'); }, true);

Subscribe to an event within a class. Manually unsubscribe when some condition is true.

class Example {
  constructor(seriesApi) {
    this._seriesApi = seriesApi;
    this._seriesApi.onDataLoaded().subscribe(this, this._onDataLoaded);
  }

  _onDataLoaded() {
    // Do something in response to the event.

    if (someUnsubscribeCondition) {
      this._seriesApi.onDataLoaded().unsubscribe(this, this._onDataLoaded);
    }
  }
}

Signature

subscribe(obj: object, member: TFunc, singleshot?: boolean) => void

Parameters

Name	Type	Description
obj	object	Object used as the this value bound to the callback function.
member	TFunc	Function called when the event is fired.
singleshot?	boolean	true if the subscription should be automatically removed after the first time it is fired.

Returns

​void

---

unsubscribe

Unsubscribe a previously subscribed callback function. It is important that the obj and member arguments are the same as the ones passed when the callback was subscribed.

Signature

unsubscribe(obj: object, member: TFunc) => void

Parameters

Name	Type	Description
obj	object	Object passed as the this value when the callback was subscribed.
member	TFunc	Function subscribed to the event.

Returns

​void

---

unsubscribeAll

Unsubscribe all callbacks that were subscribed with the same obj value.

Example

// Unsubscribe all three callback functions at once in the `destroy` method.
class Example {
  constructor(seriesApi) {
    this._seriesApi = seriesApi;
    this._seriesApi.onDataLoaded().subscribe(this, this._callback1);
    this._seriesApi.onDataLoaded().subscribe(this, this._callback2);
    this._seriesApi.onDataLoaded().subscribe(this, this._callback3);
  }

  destroy() {
    this._seriesapi.onDataLoaded().unsubscribeAll(this);
  }

  _callback1() { ... }
  _callback2() { ... }
  _callback3() { ... }
}

Signature

unsubscribeAll(obj: object) => void

Parameters

Name	Type	Description
obj	object	obj value passed when the callbacks were subscribed.

Returns

​void