How to trigger a flow on add and then again on update?

Hi there.

I’m a developer and manage a Shopify store where customers can register there email address and product code to be added to a flow which will send them the product care guide via email for that article of clothing.

This is for customers who purchase in a bricks and motar store outside of Shopify.
My products have a QR code on the tag so users know where to go.

I’ve setup a custom property that can accept one or more product codes when a user submits the form which will work with the from subscribe trigger and conditional logic to detect which product codes they’ve submitted.

The issue I have is when a user returns down the track if they’ve purchased a subsequent product then the flow isn’t triggered. 

After reading the forums I have seen a feature request for an ‘updated’ flow trigger to allow subsequent fires of a flow which would solve my problem.
I’m also aware that when a custom property is updated the original value is overwritten.

I looked into a custom metric and trigger to pass one called “Updated product codes” at the same time I submit the user to the list, however that doesn’t seem to register. Theory being that I could setup a flow off that custom metric which would then allow me to detect new subscribers to the list and then updates as well.

var _learnq = _learnq || [];

_learnq.push(["track", "Updated product codes",{

"GarmentCount": 2,

}]);

Is this achievable in Klaviyo? Am I on the right track?

I’d love to here in other suggestions or approaches if anyone has any ideas.

I have 50 products and was planning to setup the flow with 50 x conditional logic statements one for each product.