AppStateESS/homestead

/**
 * jQuery based magnetic stripe card reader "driver" to be used in web
 * applications.
 *
 * Copyright @ 2009-2010 Jonathan Stoppani (http://garetjax.info/)
 * Licensed under the MIT license (see LICENSE for details)
 * http://garetjax.info/blog/articles/2010/01/magnetic-card-jquery/
 * https://github.com/garetjax/CardReader
 */

var CardReader = function (error_start, track_start, track_end, timeout) {
    this.error_start = error_start || "é";
    this.track_start = track_start || ";";
    this.track_end = track_end || "?";
    this.timeout = timeout || 100;

    this.error_start = this.error_start.charCodeAt(0);
    this.track_start = this.track_start.charCodeAt(0);
    this.track_end = this.track_end.charCodeAt(0);

    this.started = false;
    this.finished = false;
    this.isError = false;
    this.input = "";
    this.timer = undefined;
    this.callbacks = [];
    this.errbacks = [];
    this.validators = [];
    this.isDispatching = false;
};

CardReader.prototype = {
    dispatch: function (data, isError) {
        if (!isError) {
            for (var cb in this.validators) {
                if (!this.validators[cb](data)) {
                    isError = true;
                    break;
                }
            }
        }

        if (this.isDispatching) {
            if (isError) {
                //console.log("Immediate error!");
                return;
            } else {
                clearTimeout(this.isDispatching);
            }
        }

        reader = this;

        this.isDispatching = setTimeout(function () {
            //console.log("Error timeout cleared");
            reader.isDispatching = false;
        }, 200);

        if (isError) {
            for (var cb in this.errbacks) {
                this.errbacks[cb](this.input);
            }
        } else {
            for (var cb in this.callbacks) {
                this.callbacks[cb](this.input);
            }
        }
    },

    readObserver: function (e) {
        var ob = this;

        if (!this.started && (e.which === this.track_start || e.which === this.error_start)) {
            e.stopImmediatePropagation();
            e.preventDefault();

            this.started = true;
            this.isError = e.which === this.error_start;

            this.timer = setTimeout(function () {
                ob.started = false;
                ob.finished = false;
                ob.isError = false;
                ob.input = "";
            }, this.timeout);
        } else if (this.started && e.which === this.track_end) {
            e.stopImmediatePropagation();
            e.preventDefault();

            this.finished = true;

            clearTimeout(this.timer);
            this.timer = setTimeout(function () {
                ob.started = false;
                ob.finished = false;
                ob.isError = false;
                ob.input = "";
            }, this.timeout);
        } else if (this.started && this.finished && e.which === 13) {
            e.stopImmediatePropagation();
            e.preventDefault();

            this.dispatch(this.input, this.isError);

            this.started = false;
            this.finished = false;
            this.isError = false;
            this.input = "";

            clearTimeout(this.timer);

        } else if (this.started) {
            e.stopImmediatePropagation();
            e.preventDefault();

            this.input += String.fromCharCode(e.which);

            clearTimeout(this.timer);
            this.timer = setTimeout(function () {
                ob.started = false;
                ob.finished = false;
                ob.isError = false;
                ob.input = "";
            }, this.timeout);
        }
    },

    observe: function (element) {
        var func = this;

        $(element).keypress(function (e) {
            CardReader.prototype.readObserver.apply(func, arguments);
        });
    },

    validate: function (validator) {
        this.validators.push(validator);
    },

    cardRead: function (callback) {
        this.callbacks.push(callback);
    },

    cardError: function (errback) {
        this.errbacks.push(errback);
    },
}