使用 API 路由构建表单

一个 HTML 表单会导致浏览器刷新页面或跳转到新页面。为了将表单数据发送到 API 端点，就必须要使用 JavaScript 拦截提交的表单。

本节示例向你展示了如何发送表单数据到一个 API 端点，并处理这些数据。

前期准备

• 一个带有 用于按需渲染的适配器 的项目
• 安装一个集成的 UI 框架

操作步骤

1. 在 /api/feedback 上创建一个 POST API 端点，用于接收表单数据。然后使用 request.formData() 处理表单数据。但在你使用表单值之前，请确保对其进行必要的校验。

   在这个示例中会向客户端发送一个包含响应消息的 JSON 对象。

   export const prerender = false; // 'server' 模式下不需要
   import type { APIRoute } from "astro";
   
   export const POST: APIRoute = async ({ request }) => {
     const data = await request.formData();
     const name = data.get("name");
     const email = data.get("email");
     const message = data.get("message");
     // Validate the data - you'll probably want to do more than this
     if (!name || !email || !message) {
       return new Response(
         JSON.stringify({
           message: "Missing required fields",
         }),
         { status: 400 }
       );
     }
     // Do something with the data, then return a success response
     return new Response(
       JSON.stringify({
         message: "Success!"
       }),
       { status: 200 }
     );
   };

2. 使用你的 UI 框架创建一个表单组件。每个输入字段都应该有一个描述该输入值的 name 属性。

   请确保表单中包含一个 <button> 或 <input type="submit"> 元素，用于提交表单。

   Preact

     export default function Form() {
       return (
         <form>
           <label>
             Name
             <input type="text" id="name" name="name" required />
           </label>
           <label>
             Email
             <input type="email" id="email" name="email" required />
           </label>
           <label>
             Message
             <textarea id="message" name="message" required />
           </label>
           <button>Send</button>
         </form>
       );
     }

   React

     export default function Form() {
       return (
         <form>
           <label>
             Name
             <input type="text" id="name" name="name" required />
           </label>
           <label>
             Email
             <input type="email" id="email" name="email" required />
           </label>
           <label>
             Message
             <textarea id="message" name="message" required />
           </label>
           <button>Send</button>
         </form>
       );
     }

   Solid

     export default function Form() {
       return (
         <form>
           <label>
             Name
             <input type="text" id="name" name="name" required />
           </label>
           <label>
             Email
             <input type="email" id="email" name="email" required />
           </label>
           <label>
             Message
             <textarea id="message" name="message" required />
           </label>
           <button>Send</button>
         </form>
       );
     }

   Svelte

     <form>
       <label>
         Name
         <input type="text" id="name" name="name" required />
       </label>
       <label>
         Email
         <input type="email" id="email" name="email" required />
       </label>
       <label>
         Message
         <textarea id="message" name="message" required />
       </label>
       <button>Send</button>
     </form>

   Vue

     <template>
       <form>
         <label>
           Name
           <input type="text" id="name" name="name" required />
         </label>
         <label>
           Email
           <input type="email" id="email" name="email" required />
         </label>
         <label>
           Message
           <textarea id="message" name="message" required />
         </label>
         <button>Send</button>
       </form>
     </template>

3. 创建一个函数以接受提交事件（submit event），然后将其作为 submit 事件处理器传递给你的表单。

   在函数中：

   • 调用事件的 preventDefault() 方法，以覆盖浏览器的默认提交过程。
   • 创建一个 FormData 对象，并使用 fetch 将其以 POST 请求发送到你的端点。
   Preact

     import { useState } from "preact/hooks";
   
     export default function Form() {
       const [responseMessage, setResponseMessage] = useState("");
   
       async function submit(e: SubmitEvent) {
         e.preventDefault();
         const formData = new FormData(e.target as HTMLFormElement);
         const response = await fetch("/api/feedback", {
           method: "POST",
           body: formData,
         });
         const data = await response.json();
         if (data.message) {
           setResponseMessage(data.message);
         }
       }
   
       return (
         <form onSubmit={submit}>
           <label>
             Name
             <input type="text" id="name" name="name" required />
           </label>
           <label>
             Email
             <input type="email" id="email" name="email" required />
           </label>
           <label>
             Message
             <textarea id="message" name="message" required />
           </label>
           <button>Send</button>
           {responseMessage && <p>{responseMessage}</p>}
         </form>
       );
     }

   React

     import { useState } from "react";
     import type { FormEvent } from "react";
   
     export default function Form() {
       const [responseMessage, setResponseMessage] = useState("");
   
       async function submit(e: FormEvent<HTMLFormElement>) {
         e.preventDefault();
         const formData = new FormData(e.target as HTMLFormElement);
         const response = await fetch("/api/feedback", {
           method: "POST",
           body: formData,
         });
         const data = await response.json();
         if (data.message) {
           setResponseMessage(data.message);
         }
       }
   
       return (
         <form onSubmit={submit}>
           <label htmlFor="name">
             Name
             <input type="text" id="name" name="name" autoComplete="name" required />
           </label>
           <label htmlFor="email">
             Email
             <input type="email" id="email" name="email" autoComplete="email" required />
           </label>
           <label htmlFor="message">
             Message
             <textarea id="message" name="message" autoComplete="off" required />
           </label>
           <button>Send</button>
           {responseMessage && <p>{responseMessage}</p>}
         </form>
       );
     }

   Solid

     import { createSignal, createResource, Suspense } from "solid-js";
   
     async function postFormData(formData: FormData) {
       const response = await fetch("/api/feedback", {
         method: "POST",
         body: formData,
       });
       const data = await response.json();
       return data;
     }
   
     export default function Form() {
       const [formData, setFormData] = createSignal<FormData>();
       const [response] = createResource(formData, postFormData);
   
       function submit(e: SubmitEvent) {
         e.preventDefault();
         setFormData(new FormData(e.target as HTMLFormElement));
       }
   
       return (
         <form onSubmit={submit}>
           <label>
             Name
             <input type="text" id="name" name="name" required />
           </label>
           <label>
             Email
             <input type="email" id="email" name="email" required />
           </label>
           <label>
             Message
             <textarea id="message" name="message" required />
           </label>
           <button>Send</button>
           <Suspense>{response() && <p>{response().message}</p>}</Suspense>
         </form>
       );
     }

   Svelte

     <script lang="ts">
       let responseMessage: string;
   
       async function submit(e: SubmitEvent) {
         e.preventDefault();
         const formData = new FormData(e.currentTarget as HTMLFormElement);
         const response = await fetch("/api/feedback", {
           method: "POST",
           body: formData,
         });
         const data = await response.json();
         responseMessage = data.message;
       }
     </script>
   
     <form on:submit={submit}>
       <label>
         Name
         <input type="text" id="name" name="name" required />
       </label>
       <label>
         Email
         <input type="email" id="email" name="email" required />
       </label>
       <label>
         Message
         <textarea id="message" name="message" required />
       </label>
       <button>Send</button>
       {#if responseMessage}
         <p>{responseMessage}</p>
       {/if}
     </form>

   Vue

     <script setup lang="ts">
     import { ref } from "vue";
   
     const responseMessage = ref<string>();
   
     async function submit(e: Event) {
       e.preventDefault();
       const formData = new FormData(e.currentTarget as HTMLFormElement);
       const response = await fetch("/api/feedback", {
         method: "POST",
         body: formData,
       });
       const data = await response.json();
       responseMessage.value = data.message;
     }
     </script>
   
     <template>
       <form @submit="submit">
         <label>
           Name
           <input type="text" id="name" name="name" required />
         </label>
         <label>
           Email
           <input type="email" id="email" name="email" required />
         </label>
         <label>
           Message
           <textarea id="message" name="message" required />
         </label>
         <button>Send</button>
         <p v-if="responseMessage">{{ responseMessage }}</p>
       </form>
     </template>

4. 在一个页面中导入并包含你的 <FeedbackForm /> 组件。请确认使用了 client:* 指令以确保表单逻辑能在你需要的时候被激活。

   Preact

     ---
     import FeedbackForm from "../components/FeedbackForm"
     ---
     <FeedbackForm client:load />

   React

     ---
     import FeedbackForm from "../components/FeedbackForm"
     ---
     <FeedbackForm client:load />

   Solid

     ---
     import FeedbackForm from "../components/FeedbackForm"
     ---
     <FeedbackForm client:load />

   Svelte

     ---
     import FeedbackForm from "../components/FeedbackForm.svelte"
     ---
     <FeedbackForm client:load />

   Vue

     ---
     import FeedbackForm from "../components/FeedbackForm.vue"
     ---
     <FeedbackForm client:load />