Trying to increment a customer metafield for each item in an order.

[MVS-ONE]

Currently I'm trying to create a flow where it loops through each item in an order and increments an integer field on the customer's profile:

 

When the Flow runs, it can see it successfully looping through each item in the order:

 

But the field isn't being incremented by 1 for each item as expected. If an order has 3 items in it, it will still just increment the field by 1 for the whole order.

If I make a new order, the field will be incremented by 1 each time, so I can see it's at least reading the existing value correctly.

[tim]

Why don't you calculate first and then update once?

Multiple consecutive MF updates are never good...

(my key does not match yours)

Update: the below seems to not be an issue:

Also your existing metafield reference seems odd, I'd use {{sum | plus: order.customer.metafields.custom.total_Items.value }} , but looks like they've added a new way or referencing metafields --  https://changelog.shopify.com/posts/shopify-flow-access-typed-metafields 

[MVS-ONE]

Sum is a good lead (I didn't know it existed, I just started using Flow), but I also need to be able to count only products that are in a certain collection in the order. 

[tim · Accepted solution]

Ah, that changes a lot.

In this case I'd rather jump to "update metafield" straight from the trigger and loop over line items and count in the liquid code in metafield value.

If not -- adding logging and little sleep (using Wait action) inside your loop may help if the problem is with multiple consecutive metafield updates failing.

[MVS-ONE]

Ditching the loop option in Flow and just doing it in liquid was the answer:

{%- assign counter = order.customer.stateMachinePurchases.value -%}
{%- for a in order.lineItems -%}
  {%- for b in a.product.collections -%}
    {%- if b.title == "State Machine" -%}
      {%- assign counter = counter | plus: 1 -%}
    {%- endif -%}
  {%- endfor -%}
{%- endfor -%}
{{- counter -}}

It's all good now. Thanks Tim!