Vulcan/packages/example-forum/lib/modules/posts/parameters.js

/*

Posts parameters

*/

import { Injected } from 'meteor/meteorhacks:inject-initial';
import moment from 'moment';
import { addCallback } from 'meteor/vulcan:core';

// Add 'after' and 'before' properties to terms which can be used to limit posts in time.
function addTimeParameter (parameters, terms, apolloClient) {

  // console.log('// addTimeParameter')

  if (typeof parameters.selector.postedAt === 'undefined') {

    let postedAt = {}, mAfter, mBefore, startOfDay, endOfDay, clientTimezoneOffset, serverTimezoneOffset, timeDifference;

    /*

    If we're on the client, add the time difference between client and server

    Example: client is on Japanese time (+9 hours),
    server on UCT (Greenwich) time (+0 hours), for a total difference of +9 hours.

    So the time '00:00, UCT' is equivalent to '09:00, JST'.

    So if we want to express the timestamp '00:00, UCT' on the client,
    we *add* 9 hours to '00:00, JST' on the client to get '09:00, JST' and
    sync up both times.

    */

    if (Meteor.isClient) {
      clientTimezoneOffset = -1 * new Date().getTimezoneOffset();
      serverTimezoneOffset = -1 * Injected.obj('serverTimezoneOffset').offset;
      timeDifference = clientTimezoneOffset - serverTimezoneOffset;

      // console.log('client time:'+clientTimezoneOffset);
      // console.log('server time:'+serverTimezoneOffset);
      // console.log('difference: '+timeDifference);
    }

    if (terms.after) {

      // console.log('// after: '+terms.after);

      mAfter = moment(terms.after, 'YYYY-MM-DD');
      startOfDay = mAfter.startOf('day');

        // console.log('// normal      ', mAfter.toDate(), mAfter.valueOf());
        // console.log('// startOfDay  ', startOfDay.toDate(), startOfDay.valueOf());

      if (Meteor.isClient) {
        startOfDay.add(timeDifference, 'minutes');
        // console.log('// after add   ', startOfDay.toDate(), startOfDay.valueOf());
        // note: on the client, dates are stored as strings, 
        // so use strings for MongoDB filtering options too
        postedAt.$gte = startOfDay.toISOString();
      } else {
        postedAt.$gte = startOfDay.toDate();
      }

    }

    if (terms.before) {

      mBefore = moment(terms.before, 'YYYY-MM-DD');
      endOfDay = mBefore.endOf('day');

      if (Meteor.isClient) {
        endOfDay.add(timeDifference, 'minutes');
        postedAt.$lt = endOfDay.toISOString();
      } else {
        postedAt.$lt = endOfDay.toDate();
      }

    }

    if (!_.isEmpty(postedAt)) {
      parameters.selector.postedAt = postedAt;
    }

  }

  return parameters;
}
addCallback('posts.parameters', addTimeParameter);