wikimedia/mediawiki-extensions-UniversalLanguageSelector

/*!
 * ULS GeoIP client
 *
 * Copyright (C) 2012 Alolita Sharma, Amir Aharoni, Arun Ganesh, Brandon Harris,
 * Niklas Laxström, Pau Giner, Santhosh Thottingal, Siebrand Mazeland and other
 * contributors. See CREDITS for a list.
 *
 * UniversalLanguageSelector is dual licensed GPLv2 or later and MIT. You don't
 * have to do anything special to choose one license or the other and you don't
 * have to notify anyone which license you are using. You are free to use
 * UniversalLanguageSelector in commercial projects as long as the copyright
 * header is left intact. See files GPL-LICENSE and MIT-LICENSE for details.
 *
 * @file
 * @ingroup Extensions
 * @licence GNU General Public Licence 2.0 or later
 * @licence MIT License
 */

( function () {
    'use strict';

    var geo,
        cacheAge = 60 * 60 * 8, // 8 hours
        service = mw.config.get( 'wgULSGeoService' );

    // This is not supposed to happen. For sanity prefer existing value.
    if ( window.Geo ) {
        return;
    }

    // Using cache for speed and to reduce load on the third-party service.
    // Using cookies over localStorage because cookies support automatic expiring.
    // This cookie is not currently read server-side.
    geo = mw.cookie.get( 'ULSGeo' );
    if ( geo ) {
        try {
            window.Geo = JSON.parse( geo );
            return;
        } catch ( e ) {}
    }

    $.getJSON( service ).done( function ( data ) {
        window.Geo = data;
        mw.cookie.set( 'ULSGeo', JSON.stringify( data ), cacheAge );
    } );

}() );