Uttori Event Dispatcher

An event bus system for registering, unregistering and triggering events.

Install

npm install --save @uttori/event-dispatcher

Example

const hooks = new EventDispatcher();
hooks.on('update', callback);
hooks.dispatch('update', { data }, this);
hooks.off('update', callback);

API Reference

EventDispatcher

An event bus system for registering, unregistering and triggering events.

Kind: global class
Properties

| Name | Type | Description | | --- | --- | --- | | events | Record.<string, UttoriEvent> | The collection of events to listen for. |

• EventDispatcher
  • new EventDispatcher()
  • instance
    • .events : Record.<string, UttoriEvent>
    • .validate(label, data, [context]) ⇒ Promise.<boolean>
    • .filter(label, data, [context]) ⇒ Promise.<T>
    • .dispatch(label, data, [context])
    • .fetch(label, data, [context]) ⇒ Promise.<Array.<T>>
    • .on(label, callback)
    • .once(label, callback)
    • .off(label, callback)
  • static
    • .check(label)

new EventDispatcher()

Creates a new EventDispatcher instance.

Example (new EventDispatcher())

const bus = new EventDispatcher();
bus.on('update', callback);
bus.dispatch('update', { data }, { context });
bus.off('update', callback);

eventDispatcher.events : Record.<string, UttoriEvent>

The collection of events to listen for.

Kind: instance property of EventDispatcher

eventDispatcher.validate(label, data, [context]) ⇒ Promise.<boolean>

Fires off an event with passed in data and context for a given label.

Kind: instance method of EventDispatcher
Returns: Promise.<boolean> - The conclusion of the spam checks, true being it is spam, false meaning it is clean.

| Param | Type | Description | | --- | --- | --- | | label | string | The human readable identifier of the event. | | data | any | Data to be used, updated, or modified by event callbacks. | | [context] | object | Context to help with updating or modification of the data. |

Example

is_spam = await bus.validate('check-for-spam', { data }, this);

eventDispatcher.filter(label, data, [context]) ⇒ Promise.<T>

Fires off an event with passed in data and context for a given label.

Kind: instance method of EventDispatcher
Returns: Promise.<T> - The original input data, either modified or untouched.

| Param | Type | Description | | --- | --- | --- | | label | string | The human readable identifier of the event. | | data | any | Data to be used, updated, or modified by event callbacks. | | [context] | object | Context to help with updating or modification of the data. |

Example

output = await bus.filter('loaded', { data }, this);

eventDispatcher.dispatch(label, data, [context])

Fires off an event with passed in data and context for a given label.

Kind: instance method of EventDispatcher

| Param | Type | Description | | --- | --- | --- | | label | string | The human readable identifier of the event. | | data | any | Data to be used, updated, or modified by event callbacks. | | [context] | object | Context to help with updating or modification of the data. |

Example

bus.dispatch('loaded', { data }, this);

eventDispatcher.fetch(label, data, [context]) ⇒ Promise.<Array.<T>>

Fires off an event with passed in data and context for a given label and returns an array of the results.

Kind: instance method of EventDispatcher
Returns: Promise.<Array.<T>> - An array of the results.

| Param | Type | Description | | --- | --- | --- | | label | string | The human readable identifier of the event. | | data | any | Data to be used by event callbacks. | | [context] | object | Context to help with updating or modification of the data. |

Example

popular = await bus.fetch('popular-documents', { limit: 10 }, this);

eventDispatcher.on(label, callback)

Add a function to an event that will be called when the label is dispatched. If no label is found, one is created.

Kind: instance method of EventDispatcher

| Param | Type | Description | | --- | --- | --- | | label | string | The human readable identifier of the event. | | callback | UttoriEventCallback.<any, any> | Function to be called when the event is fired. |

Example

bus.on('loaded', callback);

eventDispatcher.once(label, callback)

Add a function to an event that will be called only once when the label is dispatched. Uses the EventDispatcher.on method with a function wrapped to call off on use.

Kind: instance method of EventDispatcher

| Param | Type | Description | | --- | --- | --- | | label | string | The human readable identifier of the event. | | callback | UttoriEventCallback.<any, any> | Function to be called when the event is fired. |

Example

bus.once('one-time-process', callback);

eventDispatcher.off(label, callback)

Remove a function from an event.

Kind: instance method of EventDispatcher

| Param | Type | Description | | --- | --- | --- | | label | string | The human readable identifier of the event. | | callback | UttoriEventCallback.<any, any> | Function to be removed. |

Example

bus.off('loaded', callback);

EventDispatcher.check(label)

Verifies an event label.

Kind: static method of EventDispatcher

| Param | Type | Description | | --- | --- | --- | | label | string | The human readable identifier of the event. |

Example

EventDispatcher.check('event'); // No Error
EventDispatcher.check(1); // Throws Error

Tests

To run the test suite, first install the dependencies, then run npm test:

npm install
npm test
DEBUG=Uttori* npm test

Contributors

• Matthew Callis
• You

License

• MIT