Hi Divya,
you can check this document it’s so helpful: https://apidocs.rnd.mendix.com/8/client/mx.data.html 

best regards,
Abdelrahman Abu Al-Ata

I'm afraid I've no complete answer for you, I struggle also with it.

The reason for the undefined message, is that the nanoflow should have been declared first.

You can however provide the nanoflow as a parameter to the JS-action.

Same applies for the context.

So you get something like this:

    return new Promise(function (resolve, reject) {
        mx.data.callNanoflow({
            nanoflow: testNanoflow, // parameter JS-action
            context: testEntity, // parameter JS-action
            origin: page, // ??????
            callback: function(result) {
                alert("Nanoflow completed with result " + result);
            },
            error: function(error) {
                alert(error.message);
            }
       });

Leaves the origin I guess, perhaps somebody else can provide some final answer here.

Hi Divya,

Call I microflow could be really easy. with the Nanoflow parameter (not sure what version it was introduced)

https://docs.mendix.com/refguide/javascript-actions#2-2-2-type

Before it was a bit harder, to get the nanoflow exported, it required a helper widget

https://appstore.home.mendix.com/link/app/111132/

Alternatively, you could also return the date from the the JS action and call a sub nanoflow (now supported) with the data of your custom action.

Cheers, Andries

For those who arrive here wondering how to pass multiple parameters to the nanoflow via JS, following is a snippet:
 

export async function JS_ExecuteSyncInBackground(nanoflow, obj1, obj2, obj3) {

    // BEGIN USER CODE

    nanoflow({ParameterName1: obj1, ParameterName2: obj1, ParameterName3: obj3});

    // END USER CODE

}