Here’s a link to the template: https://shopify.com/admin/apps/flow/web/editor/templates/908286d2-3e4c-4d9d-8e28-3cf9b12db4df
If that doesn’t work, look for the one titled, “Update a product metafield if a product tag has a certain prefix”
Topic summary
A user seeks to automatically populate product metafields from prefixed tags (e.g., ‘brand_nike’) using Shopify Flow, since they cannot fully transition to metafields due to collection limitations and listing integrations.
Solution Provided:
- Flow can extract tag values after a prefix using Liquid code in the ‘Update product metafield’ action
- Template available: ‘Update a product metafield if a product tag has a certain prefix’
- Example Liquid:
{% for tag in product.tags %}{% if tag contains "brand_" %}{{ tag | remove: "brand_" }}{% endif %}{% endfor %}
Key Limitations:
- No ‘product updated’ or ‘tag updated’ trigger exists; only works on product creation or status changes
- Manual backfill possible via ‘Run Flow automation’ under ‘More actions’ for existing products
Common Issues Resolved:
- Error: ‘Value must be a single line text string’ - caused by empty values or case sensitivity mismatches between Flow conditions and Liquid code
- Solution: Use exact case matching or normalize with uppercase/lowercase, add hyphens to remove whitespace (
{{- tag -}})
Alternative Approach:
- One user successfully reversed the workflow: setting metafields with predefined options first, then generating tags from metafields to reduce human error
- ‘Run code action’ template now available as an app-free alternative