Shopify Flow: Calculating Order Balances with Metafield Magic

Diving into Dynamic Order Balance Updates with Shopify Flow

Hey everyone! I was just digging through some interesting discussions in the Shopify community, and I stumbled upon a thread that I think a lot of you will find helpful, especially if you're managing things like installment payments or custom order attributes. The original poster, andre_14, was trying to figure out how to automatically update an order's balance based on manually tracked installment payments using Shopify Flow and metafields.

It's a pretty common scenario: you have staff manually entering installment payments into a metafield, and you want the remaining balance to automatically update. Andre_14's specific setup involved a metafield called payment_installment, which contained a list of metaobjects, each representing an individual installment with its own amount. The goal was to sum up all the installment amounts and deduct that from the order's balance, storing the new balance in a balance_remaining metafield.

The Challenge: Accessing Metaobject Data in Flow

The main hurdle was figuring out how to access the 'amount' field within each metaobject in the payment_installment list so they could calculate the total paid. It's one thing to trigger a flow when a metafield updates, but it's another to actually manipulate the data inside it!

Solution 1: The "Run Code" Action

Mivicle, another community member, suggested using the "Run code" action within Flow. This is a powerful option, but it does require some coding knowledge. The key, Mivicle pointed out, is to first make sure Flow has access to the metafield data. Here's the suggested sequence:

1. After the Get order data action, add For each action, and then Log output so that the Add variable button becomes available to you
2. Using the Add variable button, select the Metafield field from For each get order data and in the opened window select the tracked metafield. This will add this metafield to the workflow, after which you will be able to select it in the Run code action. After you have added the metafield to the workflow, you can even delete the Log output action, as it was only needed to access the Add variable link
3. Next, you can add the Run code action and select the metafield values in it to calculate the new value you want to set.

Mivicle even shared a screenshot to illustrate:

Solution 2: Liquid Calculations Directly in "Update Metafield"

Another community member, tim_1, offered a potentially simpler approach. Instead of using "Run code," tim_1 suggested trying to perform the calculations directly within the "Update metafield" action using Liquid. The idea is that you could potentially access the metaobject data and perform the summation and subtraction all within the Liquid code.

Tim_1 suggested that if Liquid alone wasn't enough, you could use "get metaobject entries" and build a custom query for this by extracting MO ids from the metafield value. Then either “run code” or simply use sum action…

Breaking it Down: A Step-by-Step Approach (Combining the Advice)

Here's a consolidated approach based on the community's insights, combining the best of both suggestions:

1. Trigger: Use the Flow Trigger Extension to listen for updates to the payment_installment metafield. This part Andre_14 already had working, which is great!
2. Get Order Data: Use the "Get order data" action to retrieve the order information, including the current balance.
3. Access Metaobjects: This is where it gets interesting. Try using the "For Each" action as described by Mivicle, along with "Log output" to make the "Add variable" button available. Add the payment_installment metafield to the workflow.
4. Attempt Liquid Calculation: In the "Update metafield" action for the balance_remaining metafield, try to use Liquid to iterate through the payment_installment metaobjects and sum their 'amount' fields. Then, subtract the total from the order's balance. This might look something like this (but you'll need to adapt it to your specific metaobject structure):

{% assign total_installments = 0 %}
{% for installment in order.metafields.custom.payment_installment %}
  {% assign total_installments = total_installments | plus: installment.amount %}
{% endfor %}
{{ order.total_price | minus: total_installments }}

5. If Liquid Fails, Use "Run Code": If the Liquid approach doesn't work (and it might not, depending on the complexity of the data structure), then fall back on the "Run code" action. You'll need to write JavaScript to access the metaobject data, perform the calculations, and return the new balance.
6. Update Metafield: Finally, use the "Update metafield" action to store the calculated balance in the balance_remaining metafield.

Remember, Andre_14 posted some screenshots that are helpful for visualizing the setup:

It's worth noting that Mivicle also mentioned their Flow Companion app, which includes an "Order metafield changed" trigger. This could simplify the setup, but it's always good to explore the native options first!

So, there you have it! A breakdown of how to tackle dynamic order balance updates using Shopify Flow and metafields, inspired by a real community discussion. Remember to test thoroughly and adapt the solutions to your specific data structure. Good luck!