node.js require of a json file

Question

I am trying to require() this JSON file.

{
    "info" : function (request) {
        var i = "<pre>";
        i+= "current working directory: " + process.cwd() + "\n";
        i+="request url: " + request.url + "\n";
        i+= "</pre>";
        return i;
    }
}

Using this line

var render = require('./render.json');

But I get an exception from the JSON file of : Unexpected token u

What am I doing wrong please ?

The following works in a browser. Which I would expect, since a function is a object. And nodejs docs suggests JSON can be a module: http://nodejs.org/api/modules.html#modules_file_modules

<html>
<head>
</head>
<body>

<script>

  var a = {
    "b" : function(msg){
      alert(msg);
    }
  }

  a.b("Hello");

</script>

</body>
</html>

unexpected token "u" is because the only valid token after "f" is "a" (for "false") — Andrey Sidorov, Sep 28 '13 at 00:56
That makes perfect sense @andrey-sidorov. I am new to nodejs, so maybe modules are not what I think they are. — Anthony Scaife, Oct 01 '13 at 12:06
You're trying to mix JSON and JS here. The two languages are actually distinct from one another, despite sharing very similar syntax. JSON is basically the specific subset of JS syntax that allows you to define certain data structures - strings, booleans, numbers, Objects, and Arrays. Note that functions are *not* part of this! JS, on the other hand is... well.. everything else. Your `render.json` file isn't valid JSON *or* JS. Thus, there's no way to interpret it that makes sense in either context! tl;dr - functions aren't valid JSON. — broofa, Nov 27 '14 at 12:56

score 4 · Answer 1 · edited May 23 '17 at 10:31

4

JSON is purely meant to be a data description language. Per http://www.json.org, it is a "lightweight data-interchange format." - not a programming language.

you cannot have function inside your JSON and use node.

{
    "error": [
        function (request) {

        }
    ]

}

Is it valid to define functions in JSON results?

edited May 23 '17 at 10:31

Community

1
1

answered Sep 28 '13 at 00:50

Thalaivar

23,282
5
60
71

score 2 · Accepted Answer · edited Jan 17 '17 at 16:32

2

The way I have gotten around this is to create a js file instead of a json file:
config.js

exports.config = [
    {
        "foo": 12,
        "bar": 10,
        "baz": function(a){
            console.dir(a);
        }
    }
]

then within node:

 config = require('./config.js').config;

 var a = {
   m: 'something',
   o: 'somethingelses'
 }

 config[0].baz(a);

edited Jan 17 '17 at 16:32

Kirill

2,590
1
17
16

answered Feb 05 '14 at 06:54

Don Vawter

46
2

node.js require of a json file

2 Answers2