How to display a Javascript object in Edge Trace?

[DChiesa]

Using a Javascript policy in Apigee Edge policy flow, I set a context variable. When I view that variable in Edge Trace, I see "[object Object]". Not helpful.

The test code looks like this:

var calculator = {
    "objName": "calculator",
    "random": Math.random(),
    "start": new Date(),
    "calculate": function getPrimes(max) {
        var sieve = [],
            i, j, primes = [];
        for (i = 2; i <= max; ++i) {
            if (!sieve[i]) {
                // i has not been marked -- it is prime
                primes.push(i);
                for (j = i << 1; j <= max; j += i) {
                    sieve[j] = true;
                }
            }
        }
        return primes;
    }
};


context.setVariable("calculator", calculator);

What can I do to see the JS object more clearly?

[brandon · Accepted solution]

Easiest way to do this is to stringify the object to JSON:

context.setVariable("calculator", JSON.stringify(calculator));

[DChiesa]

yep, that's the ticket!

[DChiesa]

The key is to stringify the object before storing it into the context variable.

JSON.stringify() works for this purpose, for most JS hashes. Your code would look like this:

context.setVariable("calculator", JSON.stringify(calculator));

That won't work properly if you want to see the content of the properties of type function . JSON.stringify(), by definition, omits properties of type function from the output. To rectify this, you'd need to use a replacer function, like this:

function replacer (key, val) {
  return (typeof val === 'function') ? '' + val : val;
}
var s = JSON.stringify(calculator, replacer);
context.setVariable("calculator", s);

And the result is like so:

But even there, you don't get to see the source of the function. On the positive side, you do get to see that it IS a function.

Much better!

[adevegowda]

Dear @Dino,

You need to convert calculator into string using the below code and you will see the values :

var str_calculator = JSON.stringify(calculator);
context.setVariable("str_calculator", str_calculator);

The output will be seen as shown below:

str_calculator = {"objName":"calculator","random":0.1834675877236256,"start":"2016-02-24T17:56:47.049Z"}

Regards,

Amar