Check to see if attribute exists before creating one automatically

Ok, so I have the following set up to assign attributes to a new token automatically. on("add:character", function(obj) { createObj("attribute", { name: "Strength", current: 10, characterid: obj.id }); }); The problem is, when ever a new sandbox spins up, it adds the attribute again. Making redundant copies. I don't want this, obviously. My solution thus far has been to disable the script. However, I want to add more tokens and characters now, and it keeps adding to those that already exist. I've tried this, on("add:character", function(obj) { if (obj.get("Strength") === 0){ createObj("attribute", { name: "Strength", current: 10, characterid: obj.id }); }; }); But this doesn't work. What do I need to do to simply check if the attribute already exists? obj.get() returns the value, so I checked it against FALSE 0, rather than "0" obviously. Would this work? The error I get is: ReferenceError: Invalid left-hand side in assignment at evalmachine.:3:5 at eval ( This makes me think it's a syntax error. I'm not familiar with JavaScript, I use LUA, and Perl.

In an add:character event, obj is the character object, not the attribute object. You'll want to find the attribute with the name "Strength" and a _characterid equal to obj.id , and check if that exists: on('add:character', function (obj) { var strAttr = findObjs({ _characterid: obj.id, name: 'Strength' })[0]; // If the character doesn't have the Strength attribute, findObjs() will return a 0-length array. // The first element in a 0-length array (index 0) is undefined. // If the character has at least one Strength attribute, findObjs() will return an array with elements // and we assume the first element is the most relevant one if (!strAttr) { // `undefined` is a "falsey" value, so `!undefined` returns `true` // Create attribute Strength } }); Because characters do not have a property named "Strength", obj.get("Strength") should be returning undefined . The exactly equal operator (===) compares both value and type, and undefined is not a numeric type, like 0.

Thank you, very much. I've only been working with Roll20's API and/or JS for 2 weeks.