value-breakpoints/lib/index.js

Run specific stuff when value reaches a specific range.

"use strict";

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; }; }();

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

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

var deffy = require("deffy"),
    EventEmitter = require("events").EventEmitter,
    fnResult = require("fn-result");

var BreakpointObj = function () {
    /**
     * BreakpointObj
     * Creates a breakpoint object instance.
     *
     * @name BreakpointObj
     * @function
     * @param {Object} input An object containing the following fields:
     *
     *   - `min` (Number): The min value to be caught (default: `-Infinity`).
     *   - `max` (Number): The max value to be caught (default: `+Infinity`).
     *   - `start` (Function): The start handler (optional).
     *   - `inside` (Function): The inside handler (optional).
     *   - `end` (Function): The end handler (optional).
     *   - `event` (String): The event to be emitted when the value is in the specific range.
     *
     * @returns {BreakpointObj} The `BreakpointObj` instance containing the following fields:
     *
     *   - `min` (Number): The min value to be caught (default: `-Infinity`).
     *   - `max` (Number): The max value to be caught (default: `+Infinity`).
     *   - `handlers` (Object):
     *
     *      - `start` (Function): The start handler (optional).
     *      - `inside` (Function): The inside handler (optional).
     *      - `end` (Function): The end handler (optional).
     *
     *   - `started` (Boolean): `true`, if the value reached the min number, `false` otherwise.
     *   - `ended` (Boolean): `true`, if the value reached the max number, `false` otherwise.
     *   - `event` (String): The event to be emitted when the value is in the specific range.
     *   - `_` (Object): The original input object.
     *
     */
    function BreakpointObj(input) {
        _classCallCheck(this, BreakpointObj);

        this.min = deffy(input.min, -Infinity);
        this.max = deffy(input.max, Infinity);
        this._ = input;

        this.handlers = {
            start: input.start,
            inside: input.inside,
            end: input.end
        };

        this.started = false;
        this.ended = false;

        this.event = input.event;
    }

    /**
     * check
     *
     * @name check
     * @function
     * @param {Number} val The value to be checked.
     * @returns {Object} An object containing the following fields:
     *
     *  - `handlers` (Array): The array of functions to call.
     *  - `isInside` (Boolean): `true`, if the value is in the specified range.
     *  - `wasInside` (Boolean): `true`, if the value was in the specified range one step before.
     *
     */


    _createClass(BreakpointObj, [{
        key: "check",
        value: function check(val) {
            var handlers = [];

            var isInside = this.min <= val && val < this.max;
            var wasInside = this.wasInside;

            if (this.handlers.start && isInside && !this.started) {
                handlers.push(this.handlers.start);
                this.started = true;
            }

            if (this.handlers.inside && isInside) {
                handlers.push(this.handlers.inside);
            }

            if (this.handlers.end && wasInside && val > this.max && !this.ended) {
                handlers.push(this.handlers.end);
                this.ended = true;
            }

            this.wasInside = isInside;

            return {
                handlers: handlers,
                isInside: isInside,
                wasInside: wasInside
            };
        }
    }]);

    return BreakpointObj;
}();

var ValueBreakpoints = function (_EventEmitter) {
    _inherits(ValueBreakpoints, _EventEmitter);

    /**
     * ValueBreakpoints
     * Run specific stuff when value reaches a specific range.
     *
     * @name ValueBreakpoints
     * @function
     * @param {Array} brks An array of breakpoint objects.
     * @returns {ValueBreakpoints} The `ValueBreakpoints` extended from `EventEmitter`.
     */
    function ValueBreakpoints(brks) {
        _classCallCheck(this, ValueBreakpoints);

        var _this = _possibleConstructorReturn(this, (ValueBreakpoints.__proto__ || Object.getPrototypeOf(ValueBreakpoints)).call(this));

        brks = brks || [];
        _this.brks = [];
        _this.add(brks);
        _this._intervals = [];
        return _this;
    }

    /**
     * stop
     * Stops all the intervals.
     *
     * @name stop
     * @function
     * @returns {ValueBreakpoints} The current `ValueBreakpoints` instance.
     */


    _createClass(ValueBreakpoints, [{
        key: "stop",
        value: function stop() {
            this._intervals.forEach(function (c) {
                return c.stop();
            });
        }

        /**
         * add
         * Adds one or more breakpoints.
         *
         * @name add
         * @function
         * @param {Object} brk The breakpoint object or an array of breakpoints.
         * @returns {ValueBreakpoints} The current `ValueBreakpoints` instance.
         */

    }, {
        key: "add",
        value: function add(brk) {
            var _this2 = this;

            if (Array.isArray(brk)) {
                brk.forEach(function (c) {
                    return _this2.add(c);
                });
            } else {
                this.brks.push(new BreakpointObj(brk));
            }
            return this;
        }

        /**
         * check
         *
         * @name check
         * @function
         * @param {Function|Number} fn The function to be called when checking the value automatically. Manual checking is possible by passing a number.
         * @param {Number} interval The interval duration.
         * @returns {ValueBreakpoints} The current `ValueBreakpoints` instance (if a number was passed), or an object:
         *
         *  - `stop` (Function): If called, it will stop the checking.
         *  - `fn` (Function): The function checking the value.
         */

    }, {
        key: "check",
        value: function check(_fn, interval) {
            var _this3 = this;

            if (typeof _fn !== "function") {
                this.brks.forEach(function (c) {
                    var res = c.check(_fn);
                    res.isInside && c.event && _this3.emit(c.event, c, _fn, res);
                    res.handlers.forEach(function (cFn) {
                        return cFn(c, _fn, res);
                    });
                });
                return this;
            } else {
                interval = deffy(interval, 1000);

                var res = {
                    stop: function stop() {
                        this.stopped = true;
                    },
                    fn: function fn() {
                        if (res.stopped) {
                            return;
                        }
                        fnResult(_fn, function (err, val) {
                            if (err) {
                                return _this3.emit("error", err);
                            }
                            _this3.check(val);
                            setTimeout(res.fn, interval);
                        });
                    }
                };
                res.fn();
                this._intervals.push(res);

                return res;
            }
        }
    }]);

    return ValueBreakpoints;
}(EventEmitter);

module.exports = ValueBreakpoints;