Sharing config between node app and client side javascript

Question

I need to have some config object both in the node app and in the browser. Here is the path and the content of the config:

path: [app]/public/js/config.js
content:

var config = {
    "foo": "bar",
    "num": 42,
    "list": ["a","b","f"]
};
var isBrowser=new Function("try {return this===window;}catch(e){ return false;}");
if(!isBrowser) {
    module.exports = config;
}

In my html I just add a script element and it works fine:

<script src="/js/config.js"></script>

In node app however I do not seem to have imported the object and I get an empty object:

var config = require('./public/js/config.js');
console.log('config:', config); // gives config: {}

What am I doing wrong?

you need `module.exports = ` in the config.js for `require` to work? — Anthony Kong, Nov 14 '17 at 09:36
Why not using a standard [UMD](https://github.com/umdjs/umd) instead of the above function trick? — ghybs, Nov 14 '17 at 09:36
@AnthonyKong, I do have `module.exports =` in the config.js. — Majid Fouladpour, Nov 14 '17 at 09:38
@ghybs, I'll test that to see if it takes care of the issue. Thanks. — Majid Fouladpour, Nov 14 '17 at 09:39

score 3 · Accepted Answer · answered Nov 14 '17 at 09:40

3

Your isBrowser variable is assigned a function, but it is never executed.

Therefore it does not perform any environment detection.

answered Nov 14 '17 at 09:40

ghybs

47,565
6
74
99

Thanks! That part was borrowed (read copied) from [this answer](https://stackoverflow.com/a/31090240/66580) but I missed the function call part. Changing `if(!isBrowser) {` to `if(!isBrowser()) {` resolved the issue. – Majid Fouladpour Nov 14 '17 at 09:47

score 1 · Answer 2 · answered Nov 14 '17 at 09:44

1

The code should have been

if(!isBrowser()) {
    module.exports = config;
}

isBrowser is a function here. Since in your version !isBrowser always return false so module.exports = config is never executed.

answered Nov 14 '17 at 09:44

Anthony Kong

37,791
46
172
304

Saurabh Agrawal · Answer 3 · 2017-11-14T09:51:54.843

1

Replace if block

if(!isBrowser) {
    module.exports = config;
}

to

if(!isBrowser()) {//this isBrowser() function
    module.exports = config;
}

edited Nov 14 '17 at 09:51

answered Nov 14 '17 at 09:45

Saurabh Agrawal

7,581
2
27
51

Sharing config between node app and client side javascript

3 Answers3