Set boolean on object change Parse.com

Question

Situation:

I have a database at Parse.com. In this database I have objects which have an Array and a boolean.

Wanted Result:

I want the boolean to be set to true if the Array length is bigger than 0. And false if the size is 0.

Problem:

I do not want to set this boolean on adding/deleting from array, but i want some kind of listener that reacts on a change to the object.

A must

This solution has to be possible with only cloud code.

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Is there any way to do this?

Answer 1

Absolutely and this can be easily accomplished using a cloud code beforeSave hook.

In the beforeSave of the desired class, look at the size of the array and set the bool accordingly. This will guarantee the bool is up-to-date for every save.

Here's some sample code

// Update the boolean based on the array length
Parse.Cloud.beforeSave("yourClass", function(request, response) {

    var yourArray = request.object.get("yourArray");

    if (yourArray.length > 0) {
        request.object.set("booleanProperty", true);
    } else {
        request.object.set("booleanProperty", false);
    }
    response.success();
});