fluxtuate/lib/event-dispatcher/event-dispatcher.js

a javascript ES7 library for handling complex data transactions

"use strict";

Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.default = undefined;

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

var _invokeFunction = require("../utils/invokeFunction");

var _invokeFunction2 = _interopRequireDefault(_invokeFunction);

var _internals = require("./_internals");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

var isPaused = Symbol("fluxtuateEventDispatcher_isPaused");
var children = Symbol("fluxtuateEventDispatcher_children");
var parent = Symbol("fluxtuateEventDispatcher_parent");

function sortEvents(event1, event2) {
    if (event1.priority > event2.priority) return -1;else if (event2.priority > event1.priority) return 1;else return 0;
}

var EventDispatcher = function () {
    function EventDispatcher() {
        var _this = this;

        _classCallCheck(this, EventDispatcher);

        this[_internals.eventDispatchCallback] = null;
        this[_internals.eventMap] = {};
        this[isPaused] = false;
        this[children] = [];

        this[_internals.pause] = function () {
            _this[isPaused] = true;
        };

        this[_internals.resume] = function () {
            _this[isPaused] = false;
        };

        this[_internals.destroy] = function () {
            var cs = _this[children].slice();
            cs.forEach(function (e) {
                e[_internals.destroy]();
            });
            _this[children] = [];
            _this[parent] = undefined;
            _this[_internals.eventMap] = {};
        };

        this[_internals.propagateToParent] = function (event, payload, eventMetaData, rootDispatcher) {
            if (!eventMetaData.shouldPropagate || !eventMetaData.shouldImmediatelyPropagate) {
                return;
            }
            if (_this[parent]) {
                _this[parent][_internals.sendEvent](Object.assign({}, event, { currentTarget: _this[parent] }), payload, eventMetaData);
                if (_this[parent]) _this[parent][_internals.propagateToParent](event, payload, eventMetaData, rootDispatcher);
            } else if (rootDispatcher) {
                rootDispatcher[_internals.propagateToChildren](event, payload, eventMetaData);
            }
        };

        this[_internals.propagateToChildren] = function (event, payload, eventMetaData, rootDispatcher) {
            if (_this[children] && _this[children].length > 0) {
                for (var i = 0; i < _this[children].length; i++) {
                    if (!eventMetaData.shouldPropagate || !eventMetaData.shouldImmediatelyPropagate) {
                        break;
                    }
                    var c = _this[children][i];
                    c[_internals.sendEvent](Object.assign({}, event, { currentTarget: c }), payload, eventMetaData);
                    c[_internals.propagateToChildren](event, payload, eventMetaData);
                }
            }

            if (rootDispatcher) {
                rootDispatcher[_internals.propagateToParent](event, payload, eventMetaData);
            }
        };

        this[_internals.sendEvent] = function (event, payload, eventMetaData) {
            var eventList = _this[_internals.eventMap][event.eventName];
            if (!eventList) return;

            if (_this[_internals.eventDispatchCallback]) {
                _this[_internals.eventDispatchCallback](event, payload, eventMetaData);
            }

            eventList = eventList.slice();

            eventList = eventList.sort(sortEvents);

            for (var i = 0; i < eventList.length; i++) {
                if (!eventMetaData.shouldImmediatelyPropagate) {
                    break;
                }
                var eventObject = eventList[i];
                if (eventObject.capture && !event.capture || !eventObject.capture && event.capture) {
                    continue;
                }
                (0, _invokeFunction2.default)(eventObject.callbackFunction, [event, payload]);
                if (eventObject.oneShot) {
                    eventObject.remove();
                }
            }
        };
    }

    _createClass(EventDispatcher, [{
        key: "addChild",
        value: function addChild(eventDispatcher) {
            if (!eventDispatcher) return;
            if (this[children].indexOf(eventDispatcher) !== -1) return;

            this[children].push(eventDispatcher);
            eventDispatcher[parent] = this;
        }
    }, {
        key: "removeChild",
        value: function removeChild(eventDispatcher) {
            var index = this[children].indexOf(eventDispatcher);
            if (index === -1) return;

            this[children].splice(index, 1);
            eventDispatcher[parent] = undefined;
        }
    }, {
        key: "dispatch",
        value: function dispatch(eventName, payload) {
            if (this[isPaused]) return;

            var eventMetaData = {
                shouldPropagate: true,
                shouldImmediatelyPropagate: true
            };

            var event = {
                eventName: eventName,
                stopPropagation: function stopPropagation() {
                    eventMetaData.shouldPropagate = false;
                },
                stopImmediatePropagation: function stopImmediatePropagation() {
                    eventMetaData.shouldImmediatelyPropagate = false;
                },
                currentTarget: this,
                target: this
            };

            this[_internals.propagateToParent](event, payload, eventMetaData, this);
            this[_internals.sendEvent](event, payload, eventMetaData);

            eventMetaData = {
                shouldPropagate: true,
                shouldImmediatelyPropagate: true
            };

            event = {
                eventName: eventName,
                capture: true,
                stopPropagation: function stopPropagation() {
                    eventMetaData.shouldPropagate = false;
                },
                stopImmediatePropagation: function stopImmediatePropagation() {
                    eventMetaData.shouldImmediatelyPropagate = false;
                },
                currentTarget: this,
                target: this
            };

            this[_internals.sendEvent](event, payload, eventMetaData);
            this[_internals.propagateToChildren](event, payload, eventMetaData, this);
        }
    }, {
        key: "addListener",
        value: function addListener(eventName, callbackFunction) {
            var priority = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 0;
            var oneShot = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : false;

            if (!this[_internals.eventMap][eventName]) this[_internals.eventMap][eventName] = [];
            var self = this;

            var eventObject = {
                callbackFunction: callbackFunction,
                oneShot: oneShot,
                priority: priority,
                remove: function remove() {
                    var list = self[_internals.eventMap][eventName];
                    if (!list) return;
                    var index = list.indexOf(eventObject);
                    if (index === -1) return;
                    list.splice(index, 1);
                }
            };

            this[_internals.eventMap][eventName].push(eventObject);

            return {
                remove: eventObject.remove
            };
        }
    }, {
        key: "capture",
        value: function capture(eventName, callbackFunction) {
            var priority = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 0;
            var oneShot = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : false;

            if (!this[_internals.eventMap][eventName]) this[_internals.eventMap][eventName] = [];
            var self = this;

            var eventObject = {
                callbackFunction: callbackFunction,
                oneShot: oneShot,
                priority: priority,
                capture: true,
                remove: function remove() {
                    var list = self[_internals.eventMap][eventName];
                    if (!list) return;
                    var index = list.indexOf(eventObject);
                    if (index === -1) return;
                    list.splice(index, 1);
                }
            };

            this[_internals.eventMap][eventName].push(eventObject);

            return {
                remove: eventObject.remove
            };
        }
    }, {
        key: "children",
        get: function get() {
            return this[children].slice();
        }
    }, {
        key: "parent",
        get: function get() {
            return this[parent];
        }
    }]);

    return EventDispatcher;
}();

exports.default = EventDispatcher;