Build Forms With API Routes

An HTML form causes the browser to refresh the page or navigate to a new one. To send form data to an API endpoint instead, you must intercept the form submission using JavaScript.

This recipe shows you how to send form data to an API endpoint and handle that data.

• A project with SSR (output: 'server') enabled
• A UI Framework integration installed

1. Create a form component using your UI framework. Each input should have a name attribute that describes the value of that input.

   Be sure to include a <button> or <input type="submit"> element to submit the form.

   PreactReactSolidSvelteVue

   src/components/FeedbackForm.tsx

2. Create the post API endpoint that will receive the form data. Use request.formData() to process it. Be sure to validate the form values before you use them.

   This example sends a JSON object with a message back to the client.

   src/pages/api/feedback.ts

3. Create a function that accepts a submit event, then pass it as a submit event handler to your form. In the function, call preventDefault on the event to override the browser’s default submission process.

   Then, create a FormData object and send it to your endpoint using fetch.

   PreactReactSolidSvelteVue

   src/components/FeedbackForm.tsx

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