store.js

/**
 * Patterns store - store pattern state locally in the browser
 *
 * Copyright 2008-2012 Simplon B.V.
 * Copyright 2011 Humberto Sermeño
 * Copyright 2011 Florian Friesdorf
 */
import logging from "./logging";

const log = logging.getLogger("Patternslib Store");

function Storage(backend, prefix) {
    this.prefix = prefix;
    this.backend = backend;
}

Storage.prototype._key = function Storage_key(name) {
    return this.prefix + ":" + name;
};

Storage.prototype._allKeys = function Storage_allKeys() {
    var keys = [],
        prefix = this.prefix + ":",
        prefix_length = prefix.length,
        key,
        i;

    for (i = 0; i < this.backend.length; i++) {
        key = this.backend.key(i);
        if (key.slice(0, prefix_length) === prefix) keys.push(key);
    }
    return keys;
};

Storage.prototype.get = function Storage_get(name) {
    var key = this._key(name),
        value = this.backend.getItem(key);
    if (value !== null) {
        try {
            value = JSON.parse(value);
        } catch {
            log.warn(`Cannot parse storage value for key ${key}`);
            return;
        }
    }
    return value;
};

Storage.prototype.set = function Storage_set(name, value) {
    var key = this._key(name);
    return this.backend.setItem(key, JSON.stringify(value));
};

Storage.prototype.remove = function Storage_remove(name) {
    var key = this._key(name);
    return this.backend.removeItem(key);
};

Storage.prototype.clear = function Storage_clear() {
    var keys = this._allKeys();
    for (var i = 0; i < keys.length; i++) this.backend.removeItem(keys[i]);
};

Storage.prototype.all = function Storage_all() {
    var keys = this._allKeys(),
        prefix_length = this.prefix.length + 1,
        lk,
        data = {};

    for (var i = 0; i < keys.length; i++) {
        lk = keys[i].slice(prefix_length);
        data[lk] = JSON.parse(this.backend.getItem(keys[i]));
    }
    return data;
};

function ValueStorage(store, name) {
    this.store = store;
    this.name = name;
}

ValueStorage.prototype.get = function ValueStorage_get() {
    return this.store.get(this.name);
};

ValueStorage.prototype.set = function ValueStorage_get(value) {
    return this.store.set(this.name, value);
};

ValueStorage.prototype.remove = function ValueStorage_remove() {
    return this.store.remove(this.name);
};

var store = {
    supported: false,

    local: function (name) {
        return new Storage(window.localStorage, name);
    },

    session: function (name) {
        return new Storage(window.sessionStorage, name);
    },

    ValueStorage: ValueStorage,

    // Update storage options for a given element.
    updateOptions: function store_updateOptions(trigger, options) {
        if (options.store !== "none") {
            if (!trigger.id) {
                log.warn("state persistance requested, but element has no id");
                options.store = "none";
            } else if (!store.supported) {
                log.warn(
                    "state persistance requested, but browser does not support webstorage"
                );
                options.store = "none";
            }
        }
        return options;
    },
};

// Perform the test separately since this may throw a SecurityError as
// reported in #326
try {
    store.supported = typeof window.sessionStorage !== "undefined";
} catch (e) {
    // just ignore.
}

export default store;
export { store as Store };