Update Metafield by counting number of purchased products

[jemsuede]

Hi everyone,

I am fairly new to liquid so I hope this will be a quick answer for someone. I am looking to do the following in Shopify flow.

I currently have a metafield that will be updated every time a customer purchases an item. For instance, they have purchased 10 items in the past and have a new order of 10, the Shopify Flow will update the metafield to 20. 

This is currently where I am stuck. As I cannot seem to find the the current metafield value before adding the new order quantity. 

[paul_n]

You can't access metafields that way in Flow yet. Storefront does something special to fetch metafields values by namespace. In Flow, you loop over order.customer.metafields ... FYI if you click add variable and choose the metafield value it will show you the loop part. 

Another way to do it is using where:

{% assign my_mf = order.customer.metafields | where: "namespace", "custom" | where: "key", "pledgedcards" | first %}
{{ my_mf.value }}