feat(nuxt): add useResponseHeader composable (#27131)

docs/3.api/2.composables/use-response-header.md

@@ -0,0 +1,48 @@
+---
+title: "useResponseHeader"
+description: "Use useResponseHeader to set a server response header."
+links:
+  - label: Source
+    icon: i-simple-icons-github
+    to: https://github.com/nuxt/nuxt/blob/main/packages/nuxt/src/app/composables/ssr.ts
+    size: xs
+---
+
+::important
+This composable is available in Nuxt v3.14+.
+::
+
+You can use the built-in [`useResponseHeader`](/docs/api/composables/use-response-header) composable to set any server response header within your pages, components, and plugins.
+
+```ts
+// Set the a custom response header
+const header = useResponseHeader('X-My-Header');
+header.value = 'my-value';
+```
+
+## Example
+
+We can use `useResponseHeader` to easily set a response header on a per-page basis.
+
+```vue [pages/test.vue]
+<script setup>
+// pages/test.vue
+const header = useResponseHeader('X-My-Header');
+header.value = 'my-value';
+</script>
+
+<template>
+  <h1>Test page with custom header</h1>
+  <p>The response from the server for this "/test" page will have a custom "X-My-Header" header.</p>
+</template>
+```
+
+We can use `useResponseHeader` for example in Nuxt [middleware](/docs/guide/directory-structure/middleware) to set a response header for all pages.
+
+```ts [middleware/my-header-middleware.ts]
+export default defineNuxtRouteMiddleware((to, from) => {
+  const header = useResponseHeader('X-My-Always-Header');
+  header.value = `I'm Always here!`;
+});
+
+```

packages/nuxt/src/app/composables/index.ts

@@ -24,7 +24,7 @@ export { useFetch, useLazyFetch } from './fetch'
 export type { FetchResult, UseFetchOptions } from './fetch'
 export { useCookie, refreshCookie } from './cookie'
 export type { CookieOptions, CookieRef } from './cookie'
-export { onPrehydrate, prerenderRoutes, useRequestHeaders, useRequestEvent, useRequestFetch, setResponseStatus } from './ssr'
+export { onPrehydrate, prerenderRoutes, useRequestHeaders, useRequestEvent, useRequestFetch, setResponseStatus, useResponseHeader } from './ssr'
 export { onNuxtReady } from './ready'
 export { abortNavigation, addRouteMiddleware, defineNuxtRouteMiddleware, onBeforeRouteLeave, onBeforeRouteUpdate, setPageLayout, navigateTo, useRoute, useRouter } from './router'
 export type { AddRouteMiddlewareOptions, RouteMiddleware } from './router'

packages/nuxt/src/app/composables/ssr.ts

@@ -1,6 +1,6 @@
 import type { H3Event } from 'h3'
-import { setResponseStatus as _setResponseStatus, appendHeader, getRequestHeader, getRequestHeaders } from 'h3'
+import { setResponseStatus as _setResponseStatus, appendHeader, getRequestHeader, getRequestHeaders, getResponseHeader, removeResponseHeader, setResponseHeader } from 'h3'
-import { getCurrentInstance } from 'vue'
+import { computed, getCurrentInstance, ref } from 'vue'
 import { useServerHead } from '@unhead/vue'
 
 import type { NuxtApp } from '../nuxt'
@@ -61,6 +61,34 @@ export function setResponseStatus (arg1: H3Event | number | undefined, arg2?: nu
   }
 }
 
+/** @since 3.14.0 */
+export function useResponseHeader (header: string) {
+  if (import.meta.client) {
+    if (import.meta.dev) {
+      return computed({
+        get: () => undefined,
+        set: () => console.warn('[nuxt] Setting response headers is not supported in the browser.'),
+      })
+    }
+    return ref()
+  }
+
+  const event = useRequestEvent()!
+
+  return computed({
+    get () {
+      return getResponseHeader(event, header)
+    },
+    set (newValue) {
+      if (!newValue) {
+        return removeResponseHeader(event, header)
+      }
+
+      return setResponseHeader(event, header, newValue)
+    },
+  })
+}
+
 /** @since 3.8.0 */
 export function prerenderRoutes (path: string | string[]) {
   if (!import.meta.server || !import.meta.prerender) { return }

packages/nuxt/src/app/index.ts

@@ -1,7 +1,7 @@
 export { applyPlugin, applyPlugins, callWithNuxt, createNuxtApp, defineAppConfig, defineNuxtPlugin, definePayloadPlugin, isNuxtPlugin, registerPluginHooks, tryUseNuxtApp, useNuxtApp, useRuntimeConfig } from './nuxt'
 export type { CreateOptions, NuxtApp, NuxtPayload, NuxtPluginIndicator, NuxtSSRContext, ObjectPlugin, Plugin, PluginEnvContext, PluginMeta, ResolvedPluginMeta, RuntimeNuxtHooks } from './nuxt'
 
-export { defineNuxtComponent, useAsyncData, useLazyAsyncData, useNuxtData, refreshNuxtData, clearNuxtData, useHydration, callOnce, useState, clearNuxtState, clearError, createError, isNuxtError, showError, useError, useFetch, useLazyFetch, useCookie, refreshCookie, onPrehydrate, prerenderRoutes, useRequestHeaders, useRequestEvent, useRequestFetch, setResponseStatus, onNuxtReady, abortNavigation, addRouteMiddleware, defineNuxtRouteMiddleware, onBeforeRouteLeave, onBeforeRouteUpdate, setPageLayout, navigateTo, useRoute, useRouter, preloadComponents, prefetchComponents, preloadRouteComponents, isPrerendered, loadPayload, preloadPayload, definePayloadReducer, definePayloadReviver, getAppManifest, getRouteRules, reloadNuxtApp, useRequestURL, usePreviewMode, useId, useRouteAnnouncer, useHead, useSeoMeta, useServerSeoMeta } from './composables/index'
+export { defineNuxtComponent, useAsyncData, useLazyAsyncData, useNuxtData, refreshNuxtData, clearNuxtData, useHydration, callOnce, useState, clearNuxtState, clearError, createError, isNuxtError, showError, useError, useFetch, useLazyFetch, useCookie, refreshCookie, onPrehydrate, prerenderRoutes, useRequestHeaders, useRequestEvent, useRequestFetch, setResponseStatus, useResponseHeader, onNuxtReady, abortNavigation, addRouteMiddleware, defineNuxtRouteMiddleware, onBeforeRouteLeave, onBeforeRouteUpdate, setPageLayout, navigateTo, useRoute, useRouter, preloadComponents, prefetchComponents, preloadRouteComponents, isPrerendered, loadPayload, preloadPayload, definePayloadReducer, definePayloadReviver, getAppManifest, getRouteRules, reloadNuxtApp, useRequestURL, usePreviewMode, useId, useRouteAnnouncer, useHead, useSeoMeta, useServerSeoMeta } from './composables/index'
 export type { AddRouteMiddlewareOptions, AsyncData, AsyncDataOptions, AsyncDataRequestStatus, CookieOptions, CookieRef, FetchResult, NuxtAppManifest, NuxtAppManifestMeta, NuxtError, ReloadNuxtAppOptions, RouteMiddleware, UseFetchOptions } from './composables/index'
 
 export { defineNuxtLink } from './components/index'

packages/nuxt/src/imports/presets.ts

@@ -66,7 +66,7 @@ const granularAppPresets: InlinePreset[] = [
     from: '#app/composables/cookie',
   },
   {
-    imports: ['onPrehydrate', 'prerenderRoutes', 'useRequestHeader', 'useRequestHeaders', 'useRequestEvent', 'useRequestFetch', 'setResponseStatus'],
+    imports: ['onPrehydrate', 'prerenderRoutes', 'useRequestHeader', 'useRequestHeaders', 'useResponseHeader', 'useRequestEvent', 'useRequestFetch', 'setResponseStatus'],
     from: '#app/composables/ssr',
   },
   {

test/nuxt/composables.test.ts

@@ -12,7 +12,7 @@ import * as composables from '#app/composables'
 import { clearNuxtData, refreshNuxtData, useAsyncData, useNuxtData } from '#app/composables/asyncData'
 import { clearError, createError, isNuxtError, showError, useError } from '#app/composables/error'
 import { onNuxtReady } from '#app/composables/ready'
-import { setResponseStatus, useRequestEvent, useRequestFetch, useRequestHeaders } from '#app/composables/ssr'
+import { setResponseStatus, useRequestEvent, useRequestFetch, useRequestHeaders, useResponseHeader } from '#app/composables/ssr'
 import { clearNuxtState, useState } from '#app/composables/state'
 import { useRequestURL } from '#app/composables/url'
 import { getAppManifest, getRouteRules } from '#app/composables/manifest'
@@ -83,6 +83,7 @@ describe('composables', () => {
       'useRequestFetch',
       'isPrerendered',
       'useRequestHeaders',
+      'useResponseHeader',
       'useCookie',
       'clearNuxtState',
       'useState',
@@ -394,6 +395,7 @@ describe('ssr composables', () => {
     expect(useRequestFetch()).toEqual($fetch)
     expect(useRequestHeaders()).toEqual({})
     expect(prerenderRoutes('/')).toBeUndefined()
+    expect(useResponseHeader('x-test').value).toBeUndefined()
   })
 })