title: Shopify Product Replacement Parts
body: <p>Looking for some advice on an interesting situation using Shopify. I'm building a site for a client that has Products that have free replacement parts available. Each replacement part has variant color options.</p>
  
  <p>So far I have had the users at the company add all the replacement parts as products in the store. I have filtered the search results and the catalog results so the replacment parts are not show.</p>
  
  <p>The only place they want the replacement parts to show is when a user visits a PRODUCT, they can click a button that says order replacement parts. Then a screen will show with all the replacement parts for that product.</p>
  
  <p>A single replacement part may belong to several products and may have different color variants.</p>
  
  <p>So what I have done thus far was had the client tag all parts with at least two tags. A tag called "part" that identifies the product as a part. And one or more tags like "link:SKU123" that links the part to one or more products. Then on my Product page I was using liquid to loop all parts and display the ones that matched the products SKU. Then I found out that the for loop has a 50 item limit...</p>
  
  <p>So I looked at the product API, which would be ok, except that it has no way to filter by tags. Tags seem so handy and yet I don't see many ways to use them... So ultimately I'm looking for a way to display all replacement parts for a particular product. It doesn't have to involve tags, although the client has already tagged all the parts and I would hate to tell them it was a waste of time. But really any thoughts on how to accomplish this would be greatly appreciated.</p>
  
  <p>The only way I can think to do it, is to return all of the replacement parts and then filter through them on the page. I see the API is limited to 250 products, but I suppose I could make multiple calls until I get them all. I'm not sure how many replacment parts there are total, but I suspect there could be upwards of 1000. Seems like a waste of network resources to have to pull them all down and then filter through them...</p>
  
  <p>P.S. - the replacement parts are free, can they be run through the checkout with a zero dollar amount?</p>