feat: cross-theme cart placement for the storefront widget

Many themes only expose "Add section" for the cart's checkout area, not
"Add block" next to the actual Checkout button — Shopify gives apps no
supported way to inject a block into an arbitrary spot in a theme's own
section markup, so a manually-placed app block can only ever land as a
disconnected standalone section on those themes.

Add a JS-based fallback via the app embed (already loaded site-wide,
independent of block placement): app-embed.liquid now carries the same
config settings as the block plus an "auto-place on cart page" toggle
(default on), emitted as an inert <template> with the widget's config as
data-* attributes. datetime-widget.ts's maybeAutoPlaceOnCart() finds the
theme's own Checkout button by CSS selector (a few common patterns, most
specific first) and inserts a live widget immediately before it — skipped
entirely if a block-placed widget already exists on the page, or no
Checkout button can be found by any known selector.

Also fix shopify.app.toml: automatically_update_urls_on_dev was left on
after the app got a real, permanent production domain
(metatron-delivery.thedomainnest.com) — leaving it on meant a future local
`shopify app dev` session would silently overwrite the live app's
application_url with a temporary Cloudflare tunnel, breaking the deployed
app until someone noticed and redeployed with the real URL.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

extensions/datetime-widget/assets/datetime-widget.css

@@ -6,6 +6,16 @@
   min-height: 3.5rem; /* reserves space before JS renders content, to avoid layout shift */
 }
 
+/* Cart-page auto-injection (datetime-widget.ts's maybeAutoPlaceOnCart) lands
+   the widget as a sibling immediately before the theme's own Checkout
+   button, which can be inside a narrow flex/inline-sized wrapper — force
+   full width and give it breathing room so it doesn't get visually
+   squeezed regardless of that wrapper's own layout rules. */
+.dd-widget--cart-injected {
+  width: 100%;
+  margin-block: 1rem;
+}
+
 .dd-widget__heading {
   font-size: 1rem;
   font-weight: 600;

extensions/datetime-widget/blocks/app-embed.liquid

@@ -1,10 +1,99 @@
 {{ 'datetime-widget.css' | asset_url | stylesheet_tag }}
 <script src="{{ 'datetime-widget.js' | asset_url }}" defer="defer"></script>
 
+{% comment %}
+  Cross-theme cart placement (PRODUCT_STRATEGY.md competitive parity item):
+  a manually-placed app BLOCK only ever lands wherever the active theme's
+  own section schema declares an `@app` slot — many themes don't expose one
+  next to the cart's Checkout button at all, only "Add section" at the top
+  level, which is what was showing up as a disconnected block. Shopify
+  gives apps no supported way to inject a block into an arbitrary spot in a
+  theme's own section markup, so this app embed (always loaded site-wide,
+  independent of any block placement) instead emits an inert <template>
+  carrying the widget's config as data-* attributes; datetime-widget.js
+  finds the theme's own Checkout button by CSS selector at runtime and
+  inserts a live widget immediately before it. Best-effort — it depends on
+  the theme's Checkout button being findable by one of a few common
+  selectors (see datetime-widget.ts's CHECKOUT_BUTTON_SELECTOR) — but it's
+  the only way to get placement that isn't at the mercy of whether a given
+  theme's cart section happens to support app blocks.
+{% endcomment %}
+{% if block.settings.auto_place_cart %}
+  <template
+    id="dd-widget-cart-template"
+    data-heading="{{ block.settings.heading | escape }}"
+    data-show-shipping="{{ block.settings.show_shipping }}"
+    data-show-local-delivery="{{ block.settings.show_local_delivery }}"
+    data-show-pickup="{{ block.settings.show_pickup }}"
+    data-label-shipping="{{ 'widget.method_shipping' | t | escape }}"
+    data-label-local-delivery="{{ 'widget.method_local_delivery' | t | escape }}"
+    data-label-pickup="{{ 'widget.method_pickup' | t | escape }}"
+    data-attr-label-shipping="{{ 'widget.date_label_shipping' | t | escape }}"
+    data-attr-label-local-delivery="{{ 'widget.date_label_local_delivery' | t | escape }}"
+    data-attr-label-pickup="{{ 'widget.date_label_pickup' | t | escape }}"
+    data-label-choose-date="{{ 'widget.choose_date' | t | escape }}"
+    data-label-choose-time="{{ 'widget.choose_time' | t | escape }}"
+    data-label-no-dates="{{ 'widget.no_dates' | t | escape }}"
+    data-label-confirmed="{{ 'widget.confirmed' | t | escape }}"
+    data-label-change="{{ 'widget.change' | t | escape }}"
+    data-label-loading="{{ 'widget.loading' | t | escape }}"
+    data-label-error="{{ 'widget.error' | t | escape }}"
+    data-label-postal-code="{{ 'widget.postal_code' | t | escape }}"
+    data-label-postal-code-submit="{{ 'widget.postal_code_submit' | t | escape }}"
+    data-label-out-of-area="{{ 'widget.out_of_area' | t | escape }}"
+    {% if block.settings.location_id != blank %}data-location-id="{{ block.settings.location_id | escape }}"{% endif %}
+    {% if block.settings.google_maps_api_key != blank %}data-google-maps-api-key="{{ block.settings.google_maps_api_key | escape }}"{% endif %}
+  ></template>
+{% endif %}
+
 {% schema %}
 {
   "name": "t:app_embed.name",
   "target": "body",
-  "settings": []
+  "settings": [
+    {
+      "type": "checkbox",
+      "id": "auto_place_cart",
+      "label": "t:app_embed.auto_place_cart_label",
+      "info": "t:app_embed.auto_place_cart_info",
+      "default": true
+    },
+    {
+      "type": "text",
+      "id": "heading",
+      "label": "t:app_embed.heading_label",
+      "default": "Choose your delivery date"
+    },
+    {
+      "type": "checkbox",
+      "id": "show_shipping",
+      "label": "t:app_embed.show_shipping_label",
+      "default": true
+    },
+    {
+      "type": "checkbox",
+      "id": "show_local_delivery",
+      "label": "t:app_embed.show_local_delivery_label",
+      "default": true
+    },
+    {
+      "type": "checkbox",
+      "id": "show_pickup",
+      "label": "t:app_embed.show_pickup_label",
+      "default": true
+    },
+    {
+      "type": "text",
+      "id": "location_id",
+      "label": "t:app_embed.location_id_label",
+      "info": "t:app_embed.location_id_info"
+    },
+    {
+      "type": "text",
+      "id": "google_maps_api_key",
+      "label": "t:app_embed.google_maps_api_key_label",
+      "info": "t:app_embed.google_maps_api_key_info"
+    }
+  ]
 }
 {% endschema %}

extensions/datetime-widget/locales/en.default.schema.json

@@ -1,6 +1,16 @@
 {
   "app_embed": {
-    "name": "Delivery Date & Time"
+    "name": "Delivery Date & Time",
+    "auto_place_cart_label": "Show automatically on the cart page",
+    "auto_place_cart_info": "Inserts the picker right before your theme's Checkout button, without needing to add a block in the theme editor. Turn this off if you've already placed the \"Date & time picker\" block manually and don't want it to show twice.",
+    "heading_label": "Heading",
+    "show_shipping_label": "Show Shipping",
+    "show_local_delivery_label": "Show Local Delivery",
+    "show_pickup_label": "Show Pickup",
+    "location_id_label": "Location ID (advanced)",
+    "location_id_info": "Leave blank to use the shop's default location.",
+    "google_maps_api_key_label": "Google Maps API key",
+    "google_maps_api_key_info": "Optional — shows a map for Pickup locations. Restrict this key to your store's domain in Google Cloud Console."
   },
   "datetime_picker": {
     "name": "Date & Time Picker",

shopify.app.toml

@@ -2,14 +2,14 @@
 
 client_id = "fd503f515942a32aa8b811c1ab8c89d0"
 name = "Metatron-delivery"
-# Placeholder — `shopify app dev` overwrites this on Shopify's live app
-# record automatically each session (via automatically_update_urls_on_dev
-# below), it does NOT rewrite this file. That auto-update only works
-# because shopify.web.toml exists at the repo root telling the CLI how to
-# run this project's Remix app; without it, the CLI has no local dev-server
-# port to build a tunnel URL from and silently keeps using whatever's here
-# — which is exactly what caused the embedded admin app to never load
-# during initial setup (see shopify.web.toml's own comment).
+# The app's real, permanent production URL — PM2 (ecosystem.config.cjs)
+# keeps the Remix server running here on the actual deployment server, per
+# .env's SHOPIFY_APP_URL/PORT on that machine. NOT a placeholder anymore:
+# automatically_update_urls_on_dev is deliberately OFF (see [build] below)
+# specifically so a local `shopify app dev` session never overwrites this
+# with a temporary Cloudflare tunnel URL and breaks the live app for real
+# usage. Only change this value (and redeploy) if the production domain
+# itself changes.
 application_url = "https://metatron-delivery.thedomainnest.com"
 embedded = true
 
@@ -105,16 +105,22 @@ api_version = "unstable"
   uri = "/webhooks/events/placeholder"
 
 # App proxy so the storefront Theme App Extension can call our backend
-# without CORS issues (see IMPLEMENTATION_PLAN.md §5.3). `shopify app dev`
-# points this at your dev tunnel automatically when
-# automatically_update_urls_on_dev is true (see [build] below); if it
-# doesn't, set it manually to `<your-tunnel-url>/apps/scheduling` — the
-# Remix routes it forwards to (apps.scheduling.*.tsx) assume that exact
-# prefix.
+# without CORS issues (see IMPLEMENTATION_PLAN.md §5.3). Points at the real
+# production domain — the Remix routes it forwards to (apps.scheduling.*.tsx)
+# assume the exact /apps/scheduling prefix below.
 [app_proxy]
 url = "https://metatron-delivery.thedomainnest.com/apps/scheduling"
 subpath = "scheduling"
 prefix = "apps"
 
 [build]
-automatically_update_urls_on_dev = true
+# Deliberately OFF now that there's a real, permanent production URL above
+# — if this were true, running `shopify app dev` locally (e.g. to test a
+# theme/UI extension change) would silently overwrite application_url on
+# Shopify's live app record with a temporary Cloudflare tunnel, breaking
+# the deployed app for anyone using it until someone notices and redeploys
+# with the real URL. Local `shopify app dev` sessions still work fine for
+# testing extensions with this off; the embedded admin app just won't be
+# reachable through that session's tunnel (test it against the real
+# production domain above instead).
+automatically_update_urls_on_dev = false

widget-src/datetime-widget/datetime-widget.ts

@@ -567,11 +567,71 @@ class DateTimeWidget {
   }
 }
 
+// Cross-theme cart placement: a manually-placed app BLOCK only ever lands
+// wherever the active theme's own section schema happens to declare an
+// `@app` slot — many themes only expose "Add section" for the cart's
+// checkout area, not "Add block" next to the actual Checkout button, which
+// is what shows up as a disconnected standalone section. There's no
+// Shopify-supported way for an app to inject a block into an arbitrary
+// spot in a theme's own markup, so instead: the app embed (blocks/
+// app-embed.liquid, loaded site-wide once merchants enable it, independent
+// of any block placement) emits an inert <template id="dd-widget-cart-
+// template"> carrying the widget's config as data-* attributes. If we're
+// on the cart page, no block-placed widget already exists (avoids a
+// double render), and a Checkout button can be found by one of these
+// selectors, clone a live widget in immediately before it. Ordered
+// roughly most-to-least specific/reliable across common theme markup
+// patterns; the first match wins.
+const CHECKOUT_BUTTON_SELECTORS = [
+  'form[action*="/cart"] button[name="checkout"]',
+  'form[action*="/cart"] input[name="checkout"]',
+  '[name="checkout"]',
+  '#checkout',
+  'a[href="/checkout"]',
+];
+
+function findCheckoutButton(): HTMLElement | null {
+  for (const selector of CHECKOUT_BUTTON_SELECTORS) {
+    const el = document.querySelector<HTMLElement>(selector);
+    if (el) return el;
+  }
+  return null;
+}
+
+function isCartPage(): boolean {
+  // Matches /cart, /cart/, and locale-prefixed variants like /en/cart —
+  // but not /cart/add or similar sub-paths that aren't the cart page itself.
+  return window.location.pathname.replace(/\/+$/, "").endsWith("/cart");
+}
+
+function maybeAutoPlaceOnCart() {
+  if (!isCartPage()) return;
+  if (document.querySelector("[data-dd-widget]")) return; // a block is already placed manually — don't double up
+
+  const template = document.getElementById("dd-widget-cart-template");
+  if (!template) return; // merchant turned auto-placement off in the app embed's settings
+
+  const checkoutButton = findCheckoutButton();
+  if (!checkoutButton) return; // couldn't find a safe, theme-agnostic anchor — do nothing rather than guess
+
+  const widget = document.createElement("div");
+  widget.setAttribute("data-dd-widget", "");
+  widget.classList.add("dd-widget--cart-injected");
+  for (const attr of Array.from(template.attributes)) {
+    if (attr.name === "id") continue;
+    widget.setAttribute(attr.name, attr.value);
+  }
+
+  checkoutButton.insertAdjacentElement("beforebegin", widget);
+  new DateTimeWidget(readConfig(widget)).mount();
+}
+
 function init() {
   const roots = document.querySelectorAll<HTMLElement>("[data-dd-widget]");
   roots.forEach((root) => {
     new DateTimeWidget(readConfig(root)).mount();
   });
+  maybeAutoPlaceOnCart();
 }
 
 if (document.readyState === "loading") {