static/local.js

// Copyright (c) 2017, 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 options = require('./options');
var prefix = options.localStoragePrefix || '';

function get(key, ifNotPresent) {
    var result;
    try {
        result = window.localStorage.getItem(prefix + key);
    } catch (e) {
        // Swallow up any security exceptions...
        return ifNotPresent;
    }
    if (result === null) return ifNotPresent;
    return result;
}

function set(key, value) {
    try {
        window.localStorage.setItem(prefix + key, value);
        return true;
    } catch (e) {
        // Swallow up any security exceptions...
    }
    return false;
}

function remove(key) {
    try {
        window.localStorage.removeItem(prefix + key);
    } catch (e) {
        // Swallow up any security exceptions...
    }
}

module.exports = {
    set: set,
    get: get,
    remove: remove
};