ReferenceError - what am I doing wrong/don't I understand correctly


I want to preload data in the To Do App in the tutorial (the Blaze version)

My dir/file structure is:

 +- client
  |  +- main.cs
  |   +- main.html
  |   +- main.js
 +- api
 |    +- tasks.js
 +- ui
 |    +- body.html
 |    +- body.js
 +- package.json
 +- server
      +- main.js

The only difference with my code and the tutorial is in /server/main.js

import { Meteor } from 'meteor/meteor';

import '../imports/api/tasks.js';

Meteor.startup(() => {
  // code to run on server at startup

  // start up function that creates entries in the Websites databases.
  // code to run on server at startup
  if (!Tasks.findOne()){
    console.log("No tasks yet. Creating starter data.");
        text: "Hello world!",
        createdAt: new Date()

But I keep on getting :

W20160520-08:42:51.801(2)? (STDERR) at server/main.js:10:8
W20160520-08:42:51.800(2)? (STDERR) ReferenceError: Tasks is not defined
W20160520-08:42:51.801(2)? (STDERR) at /Users/johannesdejong/Meteor.projects/simple-todos/.meteor/local/build/programs/server/boot.js:290:5

If I read (understand) the load order correctly Load Order
/server.main.js should be loaded last and thus after /imports/api/tasks.js where the collection Tasks is defined.

Surely Tasks should be known/visible by then?

Thanks for taking the time to read this.


If you want to use ES2015 import / export you have to import the Tasks-Symbol in your main.js file:

import Tasks from '../imports/api/tasks.js';

and within tasks.js:

export default Tasks = new Meteor.Collection(....)


Thanks macrozone.

I though import ‘…/imports/api/tasks.js’; made Tasks visible.
Do I need to still keep the import ‘…/imports/api/tasks.js’; line in my code ?

The original error is solved.

I’m now getting this error : TypeError: Cannot call method ‘findOne’ of undefined

On this line: if (!Tasks.findOne()){



It depends.

Before meteor 1.3 any file would be evaulated (in a specific order). If you declare variables without var, let or const in a file, this means this variable is global (or at least package scope), but the availability of this variable is dependent on the load-order.

With meteor 1.3 this is still possible, but you can change the load order by importing files like you did.

So if you have declared the Tasks-variable as global in ../imports/api/tasks.js, then your code should work.

Maybe its best to show us the code in tasks.js


Sorry for the delay work got in the way this weekend.
No time for my new hobby :frowning:

Here the code in tasks.js

import { Mongo } from 'meteor/mongo';

export const Tasks = new Mongo.Collection('tasks');


You are exporting a named constant, so the correct syntax for your server-side import is:

import { Tasks } from '/imports/api/tasks';


Thanks Rob. Works now. :grin:

I will have to do some serious studying/reading up.

For one I tried both your import

import { Tasks } from '/imports/api/tasks';


import { Tasks } from '../imports/api/tasks.js';

Both work. Which confuses the heck out of me.
Will need to get to understand the finer points to become good at this.