static/toggles.js

// Copyright (c) 2016, Matt Godbolt
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//       this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

"use strict";
var _ = require('underscore');
var $ = require('jquery');
var EventEmitter = require('events');

function get(domRoot) {
    var result = {};
    _.each(domRoot.find(".btn"), function (a) {
        var obj = $(a);
        result[obj.data().bind] = obj.hasClass("active");
    });
    return result;
}

function Toggles(root, state) {
    EventEmitter.call(this);
    this.domRoot = root;
    state = _.extend(get(this.domRoot), state);
    this.domRoot.find('.btn')
        .click(_.bind(this.onClick, this))
        .each(function () {
            $(this).toggleClass('active', !!state[$(this).data().bind]);
        });
    this.state = state;
}

_.extend(Toggles.prototype, EventEmitter.prototype);

Toggles.prototype.get = function () {
    return _.clone(this.state);
};

Toggles.prototype.set = function (key, value) {
    this._change(function () {
        this.state[key] = value;
    }.bind(this));
};

Toggles.prototype._change = function (update) {
    var before = this.get();
    update();
    this.emit('change', before, this.get());
};

Toggles.prototype.onClick = function (event) {
    var button = $(event.currentTarget);
    if (button.hasClass("disabled")) return;
    button.toggleClass('active');
    this._change(function () {
        this.state = get(this.domRoot);
    }.bind(this));
};

module.exports = Toggles;