collection_partial_caching.md

🗃️ Efficient Collection Partial Caching

Rails can automatically cache each item in a collection when rendering a partial with cached: true, dramatically reducing view rendering time for large lists. Use render with the collection and cached: true options so that each element is cached by its model cache key. When any item changes, Rails will expire only that fragment instead of re-rendering the entire list.

<%# app/views/products/index.html.erb %>
<%= render partial: 'products/product', collection: @products, cached: true %>

<%# app/views/products/_product.html.erb %>
<div class="product" id="product-<%= product.id %>">
  <h2><%= product.name %></h2>
  <p><%= product.description.truncate(100) %></p>
</div>