blazepress/lib/collections/ActiveMap.js

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const EventEmitter = require( 'events' ).EventEmitter

/**
 *  @class
 *  A Map which emits events on mutation
 */

class ActiveMap extends Map {

	constructor( ...args ) {

		super( ...args )

		this.events = new EventEmitter;

	}

	set( ...args ) {

		Map.prototype.set.call( this, ...args )

		this.events.emit( 'set', ...args )

	}

	delete( ...args ) {

		Map.prototype.delete.call( this, ...args )

		this.events.emit( 'deleted', ...args )

	}

	clear() {

		let entries = Array.from( this.entries() )

		Set.prototype.clear.call( this )

		for( let value of entries ) {

			this.events.emit( 'deleted', value )

		}

	}

}

module.exports = ActiveMap