gpii-universal/gpii/node_modules/journal/src/JournalIdParser.js

Cross platform, core components of the GPII personalization infrastructure.

/**
 * GPII JournalIdParser.js
 *
 * Responsible for journalling the state of the system's settings in order to be able to recover from system crashes or corruption of the settings state
 *
 * Copyright 2016 Raising the Floor - International
 *
 * Licensed under the New BSD license. You may not use this file except in
 * compliance with this License.
 *
 */

"use strict";

var fluid = fluid || require("infusion");

var gpii = fluid.registerNamespace("gpii");

fluid.registerNamespace("gpii.journal");


gpii.journal.idFormatError = fluid.freezeRecursive({
    isError: true,
    message: "The only supported formats for journalId are HEAD, HEAD~, HEAD~2, etc. or <1995-10-9T10:11:12, >2009-11-29T01:02:59, etc."
});

gpii.journal.parseHeadId = function (journalId) {
    var index = journalId.substring("HEAD".length), depth = NaN;
    if (index.length > 0) {
        if (index.charAt(0) === "~") {
            var depthString = index.substring(1);
            depth = depthString.length === 0 ? 1 : fluid.parseInteger(depthString);
        } else {
            return gpii.journal.idFormatError;
        }
    } else {
        depth = 0;
    }
    if (Number.isNaN(depth)) {
        return gpii.journal.idFormatError;
    } else {
        return {
            type: "HEAD",
            depth: depth
        };
    }
};

gpii.journal.parseDateId = function (journalId) {
    var date = Date.parse(journalId.substring(1));
    return Number.isNaN(date) ? gpii.journal.idFormatError : {
        type: "DATE",
        before: journalId.charAt(0) === "<" ? 1 : -1,
        date: date
    };
};

gpii.journal.idParsers = {
    "HEAD": gpii.journal.parseHeadId,
    ">": gpii.journal.parseDateId,
    "<": gpii.journal.parseDateId
};

/** Parse a journalId specification string into a JSON form
 * @param {String} journalId - A journalId string beginning with HEAD, < or >.
 * @return {Object} A {ParsedJournalId} holding a field `type` (either "HEAD" or "DATE") and other type-specific fields.
 */

gpii.journal.parseId = function (journalId) {
    var togo = gpii.journal.idFormatError;
    fluid.each(gpii.journal.idParsers, function (func, start) {
        if (journalId.startsWith(start)) {
            togo = func(journalId);
        }
    });
    return togo;
};

/** Dereference a journalId given an array of journal files
 * @param {Array<JournalFile>} journalFiles - An array of JournalFile objects, sorted into increasing order of age.
 * @param {Object} parsed - A {ParsedJournalId} as returned from `gpii.journal.parseId` which will be used to index into `journalFiles.
 * @return {JournalFile|undefined} One of the JournalFile entries supplied, or undefined if the supplied journalId does not match.
 */
gpii.journal.fetchJournal = function (journalFiles, parsed) {
    if (parsed.type === "HEAD") {
        return journalFiles[parsed.depth];
    } else {
        var before = parsed.before;
        var toSearch = before === 1 ? journalFiles : fluid.makeArray(journalFiles).reverse();
        // For "before" - stop on the first one in reverse order (original) which is before
        // For "after" - stop on the first one in forward order (reversed) which is after
        return fluid.find_if(toSearch, function (journal) {
            return journal.createTime * before <= parsed.date * before;
        });
    }
};

/** Formats a millisecond timestamp into an ISO-8601 date string which is safe to
  * appear in a filename
  * @param {Number} time - A millisecond timestamp, as dispensed from `Date.now()`.
  * @return {String} An ISO-8601 date stamp without colon characters, e.g. 2016-07-05T220712.549Z.
  */
gpii.journal.formatTimestamp = function (time) {
    var date = new Date(time);
    var stamp = date.toISOString();
    var safeStamp = stamp.replace(/:/g, ""); // This is still a valid ISO-8601 date string, but Date.parse() will no longer parse it
    return safeStamp;
};