Question

I need to create something like the following JSON entity:

{
"foo": function() { *some code* }
}

Can any of the common JSON libraries (json, jsonb, aeron etc.) easily achieve that?
I didn’t find a way to tell the library not to quote the function part when encoding.

Thanks,

p.s. I understand the reason for not allowing such usage is to enforce correct syntax, but I’m willing to take that risk here.

Answer 1

That is not a JSON entity, but a JavaScript object. JSON has no concept of functions.

The only way to have a function encoded in JSON is indeed to encode it in a string:

{ "foo": "function() { return \"Hello, World\" }" }

When you want to execute that function in JavaScript, you’ll have to eval the string:

var jsonObj = JSON.parse('{ "foo": "function() {return \\"Hello, World\\";}" }');
var jfoo = eval('(' + jsonObj.foo + ')');
alert(jfoo()); // Shows a dialog box "Hello, World"

Note that this allows the source of the JSON to execute arbitrary JavaScript in the context of your website or application. Therefore, you should transfer data instead of functions whenever possible, and make sure not to eval code from untrusted sources.