cart/add.js JSON issues

[SuperBand]

Hi Folks. I'm writing some javascript to add multiple items to the cart. The problem I'm having is that cart.js is complaining that my JSON is invalid some how. (cart is sending back a 400)

Here's a valid JSON string that uses read variant ID's: [{"id":"13596169994330","quantity":1},{"id":"13596169994330","quantity":1},{"id":"13596169994330","quantity":1}]

What I noticed is that on the API documentation for Ajax cart, https://shopify.dev/api/ajax/reference/cart , the json examples you provide always have an 'items' element for the json.

If I hard code a JSON object with that 'items' element, it'll add all of the items to the cart without issue but I cannot for the life of me figure out how to add that 'items' element to my javascript object which is then passed through JSON.stringify(); I've been trying to figure this out for a few days now and figured maybe I'd get lucky with support.

Here's my code sample:
(the object received by the function is a simple array with variant ID's and I hard code the quantity as 1. All vars not called within the function are defined globally outside of the function)

function addBadgesToCart(obj) {

for(var i = 0; i < obj.length; i++) {

newJsObj.id = obj[i];
newJsObj.quantity = 1;
throwAwayArray.push(newJsObj)
}

var myJSON = JSON.stringify(throwAwayArray);

var xhr = new XMLHttpRequest();
xhr.open("POST", '/cart/add.js', true);
xhr.setRequestHeader('Content-Type', 'application/json; charset=UTF-8');
xhr.send(myJSON);
}

Appreciate any help!

[JHKCreate · Accepted solution]

Hi @SuperBand !

Let's try the code below:

var jsonToSend = {"items": throwAwayArray};
var myJSON = JSON.stringify(jsonToSend );

This part of the code creates a JSON object jsonToSend containing "items" as a key and your array of items as its value. It is then passed to JSON.stringify() instead of throwAwayArray.

Let me know if that works for you!

[SuperBand]

Cheers, mate! That did the trick!

[hogian]

According to JHK, this piece of the code makes a JSON object jsonToSend containing "things" as a key and your variety of things as its worth. It is then passed to JSON.stringify() rather than throwAwayArray.

[Karagel]

In order to check the validity of a string whether it is a JSON string or not, We're using the JSON File. parse()method with a few variations. JSON. parse() This method parses a JSON string and constructs the JavaScript value or object specified by the string.