From 2779b3300144f1d779647598e4eec1c41fc9f403 Mon Sep 17 00:00:00 2001
From: Harlan Wilton <harlan@harlanzw.com>
Date: Mon, 2 Jun 2025 13:23:40 +1000
Subject: [PATCH] feat: revoke script consent

---
 playground/pages/features/cookie-consent.vue  | 33 ++++++--
 .../composables/useScriptTriggerConsent.ts    | 75 ++++++++++++-------
 2 files changed, 72 insertions(+), 36 deletions(-)

diff --git a/playground/pages/features/cookie-consent.vue b/playground/pages/features/cookie-consent.vue
index 17ec3d2f..fb9639dc 100644
--- a/playground/pages/features/cookie-consent.vue
+++ b/playground/pages/features/cookie-consent.vue
@@ -8,6 +8,10 @@ function acceptCookies() {
   scriptConsent.accept()
   showCookieBanner.value = false
 }
+function revokeCookies() {
+  scriptConsent.revoke()
+  showCookieBanner.value = true
+}
 useScriptGoogleTagManager({
   id: 'GTM-MWW974PF',
   scriptOptions: {
@@ -18,16 +22,29 @@ useScriptGoogleTagManager({
 </script>
 
 <template>
-  <div v-if="showCookieBanner" id="cookie-consent" class="p-5 bg-blue-900">
-    <div class="font-bold mb-2">
-      Do you accept cookies?
+  <div>
+    <div v-if="showCookieBanner" id="cookie-consent" class="p-5 bg-blue-900">
+      <div class="font-bold mb-2">
+        Do you accept cookies?
+      </div>
+      <div class="flex items-center gap-4">
+        <UButton @click="acceptCookies">
+          Yes
+        </UButton>
+        <UButton @click="showCookieBanner = false">
+          No
+        </UButton>
+      </div>
     </div>
-    <div class="flex items-center gap-4">
-      <UButton @click="acceptCookies">
-        Yes
+    <div v-else class="p-5 bg-gray-100">
+      <div class="font-bold mb-2">
+        Cookie Status: {{ scriptConsent.consented.value ? 'Accepted' : 'Declined' }}
+      </div>
+      <UButton v-if="scriptConsent.consented.value" color="red" @click="revokeCookies">
+        Revoke Consent
       </UButton>
-      <UButton @click="showCookieBanner = false">
-        No
+      <UButton v-else color="green" @click="acceptCookies">
+        Accept Cookies
       </UButton>
     </div>
   </div>
diff --git a/src/runtime/composables/useScriptTriggerConsent.ts b/src/runtime/composables/useScriptTriggerConsent.ts
index 03abaee4..70bb9d2e 100644
--- a/src/runtime/composables/useScriptTriggerConsent.ts
+++ b/src/runtime/composables/useScriptTriggerConsent.ts
@@ -1,4 +1,4 @@
-import { isRef, ref, toValue, watch } from 'vue'
+import { isRef, type Ref, ref, toValue, watch } from 'vue'
 import { tryUseNuxtApp, onNuxtReady, requestIdleCallback } from 'nuxt/app'
 import type { ConsentScriptTriggerOptions } from '../types'
 
@@ -7,10 +7,19 @@ interface UseConsentScriptTriggerApi extends Promise<void> {
    * A function that can be called to accept the consent and load the script.
    */
   accept: () => void
+  /**
+   * A function that can be called to revoke the consent and unload the script.
+   */
+  revoke: () => void
+  /**
+   * Reactive reference to the consent state
+   */
+  consented: Ref<boolean>
 }
 
 /**
  * Load a script once consent has been provided either through a resolvable `consent` or calling the `accept` method.
+ * Supports revoking consent which will unload the script by rejecting the trigger promise.
  * @param options
  */
 export function useScriptTriggerConsent(options?: ConsentScriptTriggerOptions): UseConsentScriptTriggerApi {
@@ -18,17 +27,33 @@ export function useScriptTriggerConsent(options?: ConsentScriptTriggerOptions):
     return new Promise(() => {}) as UseConsentScriptTriggerApi
 
   const consented = ref<boolean>(false)
-  // user may want ot still load the script on idle
   const nuxtApp = tryUseNuxtApp()
-  const promise = new Promise<void>((resolve) => {
-    watch(consented, (ready) => {
-      if (ready) {
+
+  // Setup initial consent value
+  if (options?.consent) {
+    if (isRef(options?.consent)) {
+      watch(options.consent, (_val) => {
+        const val = toValue(_val)
+        consented.value = Boolean(val)
+      }, { immediate: true })
+    }
+    // check for boolean primitive
+    else if (typeof options?.consent === 'boolean') {
+      consented.value = options?.consent
+    }
+    // consent is a promise
+    else if (options?.consent instanceof Promise) {
+      options?.consent.then((res) => {
+        consented.value = typeof res === 'boolean' ? res : true
+      })
+    }
+  }
+
+  const promise = new Promise<void>((resolve, reject) => {
+    watch(consented, (newValue, oldValue) => {
+      if (newValue && !oldValue) {
+        // Consent granted - load script
         const runner = nuxtApp?.runWithContext || ((cb: () => void) => cb())
-        // TODO drop support in v1
-        if (options?.postConsentTrigger instanceof Promise) {
-          options.postConsentTrigger.then(() => runner(resolve))
-          return
-        }
         if (typeof options?.postConsentTrigger === 'function') {
           // check if function has an argument
           if (options?.postConsentTrigger.length === 1) {
@@ -50,29 +75,23 @@ export function useScriptTriggerConsent(options?: ConsentScriptTriggerOptions):
         // other trigger not supported
         runner(resolve)
       }
-    })
-    if (options?.consent) {
-      if (isRef(options?.consent)) {
-        watch(options.consent, (_val) => {
-          const val = toValue(_val)
-          consented.value = Boolean(val)
-        }, { immediate: true })
-      }
-      // check for boolean primitive
-      else if (typeof options?.consent === 'boolean') {
-        consented.value = options?.consent
+      else if (!newValue && oldValue) {
+        // Consent revoked - trigger rejection to signal script should be unloaded
+        reject(new Error('Consent revoked'))
       }
-      // consent is a promise
-      else if (options?.consent instanceof Promise) {
-        options?.consent.then((res) => {
-          consented.value = typeof res === 'boolean' ? res : true
-        })
-      }
-    }
+    })
   }) as UseConsentScriptTriggerApi
+
   // we augment the promise with a consent API
   promise.accept = () => {
     consented.value = true
   }
+
+  promise.revoke = () => {
+    consented.value = false
+  }
+
+  promise.consented = consented
+
   return promise as UseConsentScriptTriggerApi
 }