This code snippet defines a function loadLocations that parses a JSON file containing location data, groups locations by date, and stores them in a cache for efficient retrieval. It uses a custom importer module to stream the JSON data and process it asynchronously.

Run example

npm run import -- "Load location export data"

Load location export data

var importer = require('../Core');

var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];
function loadLocations(file) {
    var locationCache = {};
    var offset = (new Date()).getTimezoneOffset() * 60 * 1000;
    importer.streamJson(file, [true, {emitPath: true}], (match) => {
        if (match.path[0] === 'locations' && match.path.length === 3) {
            var currDate = new Date(parseInt(match.value.timestampMs));
            var newKey = currDate.getDate() + months[currDate.getMonth()]
                + (currDate.getFullYear() + '').substr(2, 2);
            var newRow = Object.assign({
                time: currDate,
                type: 'location',
                location: newKey
            }, match.value);
            var cache = locationCache[newRow.location];
            if (typeof cache === 'undefined') {
                cache = locationCache[newRow.location] = [];
            }
            cache[cache.length] = newRow;
        }
    })
    return locationCache;
};
module.exports = loadLocations;

const importer = require('../Core');

// Define months array for easier access
const MONTHS = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];

/**
 * Loads locations from a JSON file and caches them by date.
 * 
 * @param {string} file Path to the JSON file.
 * @returns {object} An object containing location caches.
 */
function loadLocations(file) {
    // Create a cache object to store locations
    const locationCache = {};

    // Get the current timezone offset
    const timezoneOffset = (new Date()).getTimezoneOffset() * 60 * 1000;

    // Use the importer to stream the JSON file
    importer.streamJson(file, [true, { emitPath: true }], (match) => {
        // Check if the path is locations and has a length of 3
        if (match.path[0] === 'locations' && match.path.length === 3) {
            // Parse the timestampMs value to a Date object
            const currDate = new Date(parseInt(match.value.timestampMs));

            // Create a new key for the location cache
            const newKey = `${currDate.getDate()}${MONTHS[currDate.getMonth()]}${currDate.getFullYear().toString().substr(-2)}`;

            // Create a new row object
            const newRow = {
                time: currDate,
                type: 'location',
                location: newKey,
               ...match.value,
            };

            // Get the cache for the new location
            const cache = locationCache[newRow.location];

            // If the cache is undefined, create it
            if (typeof cache === 'undefined') {
                locationCache[newRow.location] = cache = [];
            }

            // Add the new row to the cache
            cache.push(newRow);

            // Log a debug message to check the cache
            // TODO: Remove this after debugging
            // console.log(locationCache);
        }
    });

    // Return the location cache
    return locationCache;
}

module.exports = loadLocations;

This code snippet defines a function loadLocations that reads a JSON file containing location data and processes it to create a cache of locations grouped by date.

Here's a breakdown:

1. Dependencies:

   • importer: A custom module likely containing a function for streaming JSON data.

2. months Array:

   • Defines an array of abbreviated month names for date formatting.

3. loadLocations Function:

   • Takes a file path as input.
   • Initializes an empty object locationCache to store the processed location data.
   • Calculates the current timezone offset in milliseconds.
   • Uses importer.streamJson to read the JSON file asynchronously.
     • The callback function receives each JSON object (match) as it's processed.
     • It checks if the path of the current object is locations and has a length of 3.
     • If so, it extracts the timestamp, converts it to a date object, and creates a new key based on the date.
     • It then creates a new object newRow containing the location data, timestamp, type, and date key.
     • It checks if a cache entry for this location already exists in locationCache.
     • If not, it creates a new array for that location.
     • It adds the newRow to the corresponding cache entry.
   • Finally, it returns the locationCache object.

4. Module Export:

   • Exports the loadLocations function as the main module export.