Add custom domain support

client/middleware/custom-domain.global.js

@@ -1,16 +1,42 @@
-import opnformConfig from "~/opnform.config.js";
+import {customDomainUsed, getDomain, getHost} from "~/lib/utils.js";
 
-function getDomain (url) {
-  return (new URL(url)).hostname
+/**
+ * Added by Caddy when proxying to the app
+ * @type {string}
+ */
+const customDomainHeaderName = 'CUSTOM_DOMAIN_HEADER'
+
+/**
+ * List of routes that can be used with a custom domain
+ * @type {string[]}
+ */
+const customDomainAllowedRoutes = ['forms-slug']
+
+function redirectToMainDomain() {
+  return navigateTo(useRuntimeConfig().public.appUrl + '?utm_source=failed_custom_domain_redirect', { redirectCode: 301, external: true })
 }
 
 export default defineNuxtRouteMiddleware((to, from) => {
-  if (opnformConfig.custom_domains_enabled && process.client) {
-    const isCustomDomain = getDomain(window.location.href) !== getDomain(opnformConfig.app_url)
-    if (isCustomDomain && !['forms.show_public'].includes(to.name)) {
-      // If route isn't a public form, redirect
-      return navigateTo({name: 'home',query: {utm_source: 'failed_custom_domain_redirect'}});
-    }
+  if (process.client) return
+
+  const config = useRuntimeConfig()
+
+  if (!customDomainUsed()) return
+
+  const customDomainHeaderValue = useRequestHeaders()[customDomainHeaderName]
+  if (!customDomainHeaderValue || customDomainHeaderValue !== getDomain(getHost())) {
+    // If custom domain header doesn't match, redirect
+    return redirectToMainDomain()
+  }
+
+  if (!config.public.customDomainsEnabled) {
+    // If custom domain not allowed, redirect
+    return redirectToMainDomain()
+  }
+
+  if (!customDomainAllowedRoutes.includes(to.name)) {
+    // Custom domain only allowed for form url
+    return redirectToMainDomain()
   }
 })