Make image, variant, and cart updates faster with useOptimistic (#1365)

components/product/variant-selector.tsx

@@ -1,14 +1,13 @@
 'use client';
 
 import clsx from 'clsx';
+import { useProduct, useUpdateURL } from 'components/product/product-context';
 import { ProductOption, ProductVariant } from 'lib/shopify/types';
-import { createUrl } from 'lib/utils';
-import { usePathname, useRouter, useSearchParams } from 'next/navigation';
 
 type Combination = {
   id: string;
   availableForSale: boolean;
-  [key: string]: string | boolean; // ie. { color: 'Red', size: 'Large', ... }
+  [key: string]: string | boolean;
 };
 
 export function VariantSelector({
@@ -18,9 +17,8 @@ export function VariantSelector({
   options: ProductOption[];
   variants: ProductVariant[];
 }) {
-  const router = useRouter();
-  const pathname = usePathname();
-  const searchParams = useSearchParams();
+  const { state, updateOption } = useProduct();
+  const updateURL = useUpdateURL();
   const hasNoOptionsOrJustOneOption =
     !options.length || (options.length === 1 && options[0]?.values.length === 1);
 
@@ -31,7 +29,6 @@ export function VariantSelector({
   const combinations: Combination[] = variants.map((variant) => ({
     id: variant.id,
     availableForSale: variant.availableForSale,
-    // Adds key / value pairs for each variant (ie. "color": "Black" and "size": 'M").
     ...variant.selectedOptions.reduce(
       (accumulator, option) => ({ ...accumulator, [option.name.toLowerCase()]: option.value }),
       {}
@@ -39,68 +36,58 @@ export function VariantSelector({
   }));
 
   return options.map((option) => (
-    <dl className="mb-8" key={option.id}>
-      <dt className="mb-4 text-sm uppercase tracking-wide">{option.name}</dt>
-      <dd className="flex flex-wrap gap-3">
-        {option.values.map((value) => {
-          const optionNameLowerCase = option.name.toLowerCase();
+    <form key={option.id}>
+      <dl className="mb-8">
+        <dt className="mb-4 text-sm uppercase tracking-wide">{option.name}</dt>
+        <dd className="flex flex-wrap gap-3">
+          {option.values.map((value) => {
+            const optionNameLowerCase = option.name.toLowerCase();
 
-          // Base option params on current params so we can preserve any other param state in the url.
-          const optionSearchParams = new URLSearchParams(searchParams.toString());
+            // Base option params on current selectedOptions so we can preserve any other param state.
+            const optionParams = { ...state, [optionNameLowerCase]: value };
 
-          // Update the option params using the current option to reflect how the url *would* change,
-          // if the option was clicked.
-          optionSearchParams.set(optionNameLowerCase, value);
-          const optionUrl = createUrl(pathname, optionSearchParams);
+            // Filter out invalid options and check if the option combination is available for sale.
+            const filtered = Object.entries(optionParams).filter(([key, value]) =>
+              options.find(
+                (option) => option.name.toLowerCase() === key && option.values.includes(value)
+              )
+            );
+            const isAvailableForSale = combinations.find((combination) =>
+              filtered.every(
+                ([key, value]) => combination[key] === value && combination.availableForSale
+              )
+            );
 
-          // In order to determine if an option is available for sale, we need to:
-          //
-          // 1. Filter out all other param state
-          // 2. Filter out invalid options
-          // 3. Check if the option combination is available for sale
-          //
-          // This is the "magic" that will cross check possible variant combinations and preemptively
-          // disable combinations that are not available. For example, if the color gray is only available in size medium,
-          // then all other sizes should be disabled.
-          const filtered = Array.from(optionSearchParams.entries()).filter(([key, value]) =>
-            options.find(
-              (option) => option.name.toLowerCase() === key && option.values.includes(value)
-            )
-          );
-          const isAvailableForSale = combinations.find((combination) =>
-            filtered.every(
-              ([key, value]) => combination[key] === value && combination.availableForSale
-            )
-          );
+            // The option is active if it's in the selected options.
+            const isActive = state[optionNameLowerCase] === value;
 
-          // The option is active if it's in the url params.
-          const isActive = searchParams.get(optionNameLowerCase) === value;
-
-          return (
-            <button
-              key={value}
-              aria-disabled={!isAvailableForSale}
-              disabled={!isAvailableForSale}
-              onClick={() => {
-                router.replace(optionUrl, { scroll: false });
-              }}
-              title={`${option.name} ${value}${!isAvailableForSale ? ' (Out of Stock)' : ''}`}
-              className={clsx(
-                'flex min-w-[48px] items-center justify-center rounded-full border bg-neutral-100 px-2 py-1 text-sm dark:border-neutral-800 dark:bg-neutral-900',
-                {
-                  'cursor-default ring-2 ring-blue-600': isActive,
-                  'ring-1 ring-transparent transition duration-300 ease-in-out hover:scale-110 hover:ring-blue-600 ':
-                    !isActive && isAvailableForSale,
-                  'relative z-10 cursor-not-allowed overflow-hidden bg-neutral-100 text-neutral-500 ring-1 ring-neutral-300 before:absolute before:inset-x-0 before:-z-10 before:h-px before:-rotate-45 before:bg-neutral-300 before:transition-transform dark:bg-neutral-900 dark:text-neutral-400 dark:ring-neutral-700 before:dark:bg-neutral-700':
-                    !isAvailableForSale
-                }
-              )}
-            >
-              {value}
-            </button>
-          );
-        })}
-      </dd>
-    </dl>
+            return (
+              <button
+                formAction={() => {
+                  const newState = updateOption(optionNameLowerCase, value);
+                  updateURL(newState);
+                }}
+                key={value}
+                aria-disabled={!isAvailableForSale}
+                disabled={!isAvailableForSale}
+                title={`${option.name} ${value}${!isAvailableForSale ? ' (Out of Stock)' : ''}`}
+                className={clsx(
+                  'flex min-w-[48px] items-center justify-center rounded-full border bg-neutral-100 px-2 py-1 text-sm dark:border-neutral-800 dark:bg-neutral-900',
+                  {
+                    'cursor-default ring-2 ring-blue-600': isActive,
+                    'ring-1 ring-transparent transition duration-300 ease-in-out hover:ring-blue-600':
+                      !isActive && isAvailableForSale,
+                    'relative z-10 cursor-not-allowed overflow-hidden bg-neutral-100 text-neutral-500 ring-1 ring-neutral-300 before:absolute before:inset-x-0 before:-z-10 before:h-px before:-rotate-45 before:bg-neutral-300 before:transition-transform dark:bg-neutral-900 dark:text-neutral-400 dark:ring-neutral-700 before:dark:bg-neutral-700':
+                      !isAvailableForSale
+                  }
+                )}
+              >
+                {value}
+              </button>
+            );
+          })}
+        </dd>
+      </dl>
+    </form>
   ));
 }