devextreme/dist/transpiled/core/events_strategy.js

HTML5 JavaScript Component Suite for Responsive Web Development

"use strict";

var Callbacks = require("./utils/callbacks"),
    isFunction = require("./utils/type").isFunction,
    each = require("./utils/iterator").each,
    Class = require("./class");

module.exports = Class.inherit({
    ctor: function ctor(owner) {
        this._events = {};
        this._owner = owner;
    },

    hasEvent: function hasEvent(eventName) {
        var callbacks = this._events[eventName];
        if (callbacks) {
            return callbacks.has();
        }
        return false;
    },

    fireEvent: function fireEvent(eventName, eventArgs) {
        var callbacks = this._events[eventName];
        if (callbacks) {
            callbacks.fireWith(this._owner, eventArgs);
        }
    },

    on: function on(eventName, eventHandler) {
        var callbacks = this._events[eventName],
            addFn;

        if (!callbacks) {
            callbacks = Callbacks();
            this._events[eventName] = callbacks;
        }
        addFn = callbacks.originalAdd || callbacks.add;
        addFn.call(callbacks, eventHandler);
    },

    off: function off(eventName, eventHandler) {
        var callbacks = this._events[eventName];
        if (callbacks) {
            if (isFunction(eventHandler)) {
                callbacks.remove(eventHandler);
            } else {
                callbacks.empty();
            }
        }
    },

    dispose: function dispose() {
        each(this._events, function () {
            this.empty();
        });
    }
});