Selecting a variant before add to cart

Topic summary

Goal: require selecting a size variant before enabling Add to Cart; otherwise prompt “Select a size.”

Proposed approach: locate variant rendering in product.liquid/product-template.liquid, wrap/identify the Add to Cart button, and add JavaScript to listen for variant selection changes. An example jQuery snippet was shared to keep the button disabled until a non-empty option is chosen.

Shared add-to-cart Liquid shows conditions (sold_out, variantCount, color swatches, Quick Shop) and renders Add to Cart, Pre-Order, or a Select Options link, but it does not include JavaScript to enforce selection-first behavior.

Access was requested to implement changes; the store owner declined due to privacy and asked for guidance using the posted code. Two other participants asked for help applying the same logic to their stores.

Outcome: no finalized implementation; discussion remains open. Action item: add a selection-change handler targeting the variant dropdown and the existing Add to Cart button so the button stays disabled until a valid variant is selected. Code snippets are central to understanding the proposed solution.

Summarized with AI on January 2. AI used: gpt-5.

hi, would like to use this logic in my shopify store. Can you help me out?