Cómo añadir un formulario de contacto a un sitio estático sin backend

<form id="contact" action="https://ikiform.com/f/frm_xxxxxxxxxxxxxxxx" method="post">
  <label for="name">Name</label>
  <input id="name" name="name" autocomplete="name" maxlength="120" required />
  <p class="field-error" data-error-for="name" hidden></p>

  <label for="email">Email</label>
  <input id="email" name="email" type="email" autocomplete="email" required />
  <p class="field-error" data-error-for="email" hidden></p>

  <label for="message">Message</label>
  <textarea id="message" name="message" rows="6" minlength="10" maxlength="5000" required></textarea>
  <p class="field-error" data-error-for="message" hidden></p>

  <input type="hidden" name="_redirect" value="https://example.com/thanks.html" />
  <input name="_gotcha" type="text" tabindex="-1" autocomplete="off" hidden />
  <button type="submit">Send message</button>
  <p id="contact-status" role="status"></p>
</form>
<p id="contact-sent" role="status" hidden>Thanks. Your message is on its way, and I'll reply by email.</p>

<script src="/contact.js" defer></script>

const form = document.querySelector("#contact");
const status = document.querySelector("#contact-status");
const done = document.querySelector("#contact-sent");
const button = form.querySelector("button");

function showErrors(fields = {}) {
  for (const slot of form.querySelectorAll("[data-error-for]")) {
    const name = slot.dataset.errorFor;
    const message = fields[name]?.[0] ?? "";
    slot.textContent = message;
    slot.hidden = !message;
    form.elements[name]?.setAttribute("aria-invalid", message ? "true" : "false");
  }
}

form.addEventListener("submit", async (event) => {
  event.preventDefault();
  button.disabled = true;
  status.textContent = "Sending";
  try {
    const response = await fetch(form.action, {
      method: "POST",
      headers: { Accept: "application/json" },
      body: new FormData(form),
    });
    const result = await response.json();
    if (result.ok) {
      form.hidden = true;
      done.hidden = false;
      return;
    }
    showErrors(result.error.fields);
    status.textContent = result.error.message;
  } catch {
    status.textContent = "Couldn't send. Check your connection and try again.";
  }
  button.disabled = false;
});

import type { NextConfig } from "next";

const nextConfig: NextConfig = {
  output: "export",
};

export default nextConfig;

"use client";

import { type FormEvent, useState } from "react";

const ENDPOINT = "https://ikiform.com/f/frm_xxxxxxxxxxxxxxxx";

type Field = "name" | "email" | "message";
type Errors = Partial<Record<Field, string>>;

export function ContactForm() {
  const [sentTo, setSentTo] = useState("");
  const [sending, setSending] = useState(false);
  const [errors, setErrors] = useState<Errors>({});
  const [notice, setNotice] = useState("");

  async function onSubmit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    const body = new FormData(event.currentTarget);
    setSending(true);
    setNotice("");
    try {
      const response = await fetch(ENDPOINT, { method: "POST", headers: { Accept: "application/json" }, body });
      const result = await response.json();
      if (result.ok) {
        setSentTo(String(body.get("email")));
        return;
      }
      const fields = result.error.fields ?? {};
      setErrors({ name: fields.name?.[0], email: fields.email?.[0], message: fields.message?.[0] });
      setNotice(result.error.message);
    } catch {
      setNotice("Couldn't send. Check your connection and try again.");
    } finally {
      setSending(false);
    }
  }

  if (sentTo) return <p role="status">Thanks. I'll reply to {sentTo}.</p>;

  return (
    <form action={ENDPOINT} method="post" onSubmit={onSubmit}>
      <label htmlFor="name">Name</label>
      <input id="name" name="name" autoComplete="name" maxLength={120} required aria-invalid={!!errors.name} />
      {errors.name ? <p>{errors.name}</p> : null}
      <label htmlFor="email">Email</label>
      <input id="email" name="email" type="email" autoComplete="email" required aria-invalid={!!errors.email} />
      {errors.email ? <p>{errors.email}</p> : null}
      <label htmlFor="message">Message</label>
      <textarea id="message" name="message" rows={6} minLength={10} required aria-invalid={!!errors.message} />
      {errors.message ? <p>{errors.message}</p> : null}
      <input name="_gotcha" type="text" tabIndex={-1} autoComplete="off" hidden />
      {notice ? <p role="alert">{notice}</p> : null}
      <button disabled={sending}>{sending ? "Sending" : "Send message"}</button>
    </form>
  );
}

---
import Layout from "../layouts/Layout.astro";

const endpoint = "https://ikiform.com/f/frm_xxxxxxxxxxxxxxxx";
---

<Layout title="Contact">
  <form id="contact" action={endpoint} method="post">
    <label for="name">Name</label>
    <input id="name" name="name" autocomplete="name" required />
    <label for="email">Email</label>
    <input id="email" name="email" type="email" autocomplete="email" required />
    <label for="message">Message</label>
    <textarea id="message" name="message" rows="6" minlength="10" required></textarea>
    <input type="hidden" name="_redirect" value={new URL("/thanks/", Astro.site).href} />
    <input name="_gotcha" type="text" tabindex="-1" autocomplete="off" hidden />
    <button>Send message</button>
    <output id="contact-status" role="status"></output>
  </form>
</Layout>

<script>
  const form = document.querySelector<HTMLFormElement>("#contact")!;
  const status = document.querySelector<HTMLOutputElement>("#contact-status")!;

  form.addEventListener("submit", async (event) => {
    event.preventDefault();
    status.value = "Sending";
    const response = await fetch(form.action, {
      method: "POST",
      headers: { Accept: "application/json" },
      body: new FormData(form),
    }).catch(() => null);
    const result = await response?.json().catch(() => null);
    if (result?.ok) {
      form.replaceWith(Object.assign(document.createElement("p"), { textContent: "Thanks. Your message is on its way, and I'll reply by email." }));
      return;
    }
    const fields: Record<string, string[]> = result?.error?.fields ?? {};
    const first = Object.entries(fields)[0];
    status.value = first ? `${first[0]}: ${first[1][0]}` : (result?.error?.message ?? "Couldn't send. Check your connection and try again.");
  });
</script>

import { tanstackStart } from "@tanstack/react-start/plugin/vite";
import viteReact from "@vitejs/plugin-react";
import { defineConfig } from "vite";

export default defineConfig({
  plugins: [
    tanstackStart({
      spa: {
        enabled: true,
      },
    }),
    viteReact(),
  ],
});

import { createFileRoute, useNavigate } from "@tanstack/react-router";
import { type FormEvent, useState } from "react";

const ENDPOINT = "https://ikiform.com/f/frm_xxxxxxxxxxxxxxxx";

export const Route = createFileRoute("/contact")({ component: Contact });

function Contact() {
  const navigate = useNavigate();
  const [problems, setProblems] = useState<string[]>([]);
  const [sending, setSending] = useState(false);

  async function onSubmit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    setSending(true);
    try {
      const response = await fetch(ENDPOINT, {
        method: "POST",
        headers: { Accept: "application/json" },
        body: new FormData(event.currentTarget),
      });
      const result = await response.json();
      if (result.ok) {
        await navigate({ to: "/thanks" });
        return;
      }
      const fields: Record<string, string[]> = result.error.fields ?? {};
      setProblems(Object.keys(fields).length ? Object.values(fields).map((list) => list[0]) : [result.error.message]);
    } catch {
      setProblems(["Couldn't send. Check your connection and try again."]);
    }
    setSending(false);
  }

  return (
    <form action={ENDPOINT} method="post" onSubmit={onSubmit}>
      {problems.length ? (
        <ul role="alert">
          {problems.map((problem) => (
            <li key={problem}>{problem}</li>
          ))}
        </ul>
      ) : null}
      <label htmlFor="name">Name</label>
      <input id="name" name="name" autoComplete="name" required />
      <label htmlFor="email">Email</label>
      <input id="email" name="email" type="email" autoComplete="email" required />
      <label htmlFor="message">Message</label>
      <textarea id="message" name="message" rows={6} minLength={10} required />
      <input name="_gotcha" type="text" tabIndex={-1} autoComplete="off" hidden />
      <button disabled={sending}>{sending ? "Sending" : "Send message"}</button>
    </form>
  );
}

import type { Config } from "@react-router/dev/config";

export default {
  ssr: false,
} satisfies Config;

import { Form, redirect, useNavigation } from "react-router";
import type { Route } from "./+types/contact";

const ENDPOINT = "https://ikiform.com/f/frm_xxxxxxxxxxxxxxxx";

export async function clientAction({ request }: Route.ClientActionArgs) {
  const response = await fetch(ENDPOINT, {
    method: "POST",
    headers: { Accept: "application/json" },
    body: await request.formData(),
  });
  const result = await response.json();
  if (result.ok) return redirect("/thanks");
  return {
    fields: (result.error.fields ?? {}) as Record<string, string[]>,
    message: String(result.error.message),
  };
}

export default function Contact({ actionData }: Route.ComponentProps) {
  const sending = useNavigation().state === "submitting";
  const error = (name: string) => actionData?.fields[name]?.[0];

  return (
    <Form method="post">
      <label htmlFor="name">Name</label>
      <input id="name" name="name" autoComplete="name" required />
      {error("name") ? <p>{error("name")}</p> : null}
      <label htmlFor="email">Email</label>
      <input id="email" name="email" type="email" autoComplete="email" required />
      {error("email") ? <p>{error("email")}</p> : null}
      <label htmlFor="message">Message</label>
      <textarea id="message" name="message" rows={6} minLength={10} required />
      {error("message") ? <p>{error("message")}</p> : null}
      <input name="_gotcha" type="text" tabIndex={-1} autoComplete="off" hidden />
      {actionData?.message ? <p role="alert">{actionData.message}</p> : null}
      <button disabled={sending}>{sending ? "Sending" : "Send message"}</button>
    </Form>
  );
}

export const prerender = true;

<script lang="ts">
  const ENDPOINT = "https://ikiform.com/f/frm_xxxxxxxxxxxxxxxx";

  let phase = $state<"idle" | "sending" | "sent">("idle");
  let errors = $state<Record<string, string[]>>({});
  let notice = $state("");

  async function send(event: SubmitEvent) {
    event.preventDefault();
    phase = "sending";
    notice = "";
    try {
      const response = await fetch(ENDPOINT, {
        method: "POST",
        headers: { Accept: "application/json" },
        body: new FormData(event.currentTarget as HTMLFormElement),
      });
      const result = await response.json();
      if (result.ok) {
        phase = "sent";
        return;
      }
      errors = result.error.fields ?? {};
      notice = result.error.message;
    } catch {
      notice = "Couldn't send. Check your connection and try again.";
    }
    phase = "idle";
  }
</script>

{#if phase === "sent"}
  <p role="status">Thanks. Your message is on its way, and I'll reply by email.</p>
{:else}
  <form action={ENDPOINT} method="post" onsubmit={send}>
    <label for="name">Name</label>
    <input id="name" name="name" autocomplete="name" required aria-invalid={!!errors.name} />
    {#if errors.name}<p>{errors.name[0]}</p>{/if}
    <label for="email">Email</label>
    <input id="email" name="email" type="email" autocomplete="email" required aria-invalid={!!errors.email} />
    {#if errors.email}<p>{errors.email[0]}</p>{/if}
    <label for="message">Message</label>
    <textarea id="message" name="message" rows="6" minlength="10" required aria-invalid={!!errors.message}></textarea>
    {#if errors.message}<p>{errors.message[0]}</p>{/if}
    <input name="_gotcha" type="text" tabindex="-1" autocomplete="off" hidden />
    {#if notice}<p role="alert">{notice}</p>{/if}
    <button disabled={phase === "sending"}>{phase === "sending" ? "Sending" : "Send message"}</button>
  </form>
{/if}

<script setup lang="ts">
const ENDPOINT = "https://ikiform.com/f/frm_xxxxxxxxxxxxxxxx";

const form = reactive({ name: "", email: "", message: "", _gotcha: "" });
const errors = ref<Record<string, string[]>>({});
const notice = ref("");
const sending = ref(false);

async function send() {
  sending.value = true;
  notice.value = "";
  try {
    await $fetch(ENDPOINT, { method: "POST", headers: { Accept: "application/json" }, body: form });
    await navigateTo("/thanks");
  } catch (failure) {
    const data = (failure as { data?: { error?: { message?: string; fields?: Record<string, string[]> } } }).data;
    errors.value = data?.error?.fields ?? {};
    notice.value = data?.error?.message ?? "Couldn't send. Check your connection and try again.";
  } finally {
    sending.value = false;
  }
}
</script>

<template>
  <form :action="ENDPOINT" method="post" @submit.prevent="send">
    <label for="name">Name</label>
    <input id="name" v-model="form.name" name="name" autocomplete="name" required />
    <p v-if="errors.name">{{ errors.name[0] }}</p>
    <label for="email">Email</label>
    <input id="email" v-model="form.email" name="email" type="email" autocomplete="email" required />
    <p v-if="errors.email">{{ errors.email[0] }}</p>
    <label for="message">Message</label>
    <textarea id="message" v-model="form.message" name="message" rows="6" minlength="10" required />
    <p v-if="errors.message">{{ errors.message[0] }}</p>
    <input v-model="form._gotcha" name="_gotcha" type="text" tabindex="-1" autocomplete="off" hidden />
    <p v-if="notice" role="alert">{{ notice }}</p>
    <button :disabled="sending">{{ sending ? "Sending" : "Send message" }}</button>
  </form>
</template>

VITE_IKIFORM_ENDPOINT=https://ikiform.com/f/frm_xxxxxxxxxxxxxxxx

import { type FormEvent, useState } from "react";

const ENDPOINT = import.meta.env.VITE_IKIFORM_ENDPOINT;

type Status = { kind: "idle" } | { kind: "sending" } | { kind: "sent" } | { kind: "failed"; lines: string[] };

export function ContactForm() {
  const [status, setStatus] = useState<Status>({ kind: "idle" });

  async function onSubmit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    const body = new FormData(event.currentTarget);
    setStatus({ kind: "sending" });
    try {
      const response = await fetch(ENDPOINT, { method: "POST", headers: { Accept: "application/json" }, body });
      const result = await response.json();
      if (result.ok) return setStatus({ kind: "sent" });
      const fields: Record<string, string[]> = result.error.fields ?? {};
      const lines = Object.entries(fields).map(([name, list]) => `${name}: ${list[0]}`);
      setStatus({ kind: "failed", lines: lines.length ? lines : [result.error.message] });
    } catch {
      setStatus({ kind: "failed", lines: ["Couldn't send. Check your connection and try again."] });
    }
  }

  if (status.kind === "sent") return <p role="status">Thanks. Your message is on its way, and I'll reply by email.</p>;

  return (
    <form action={ENDPOINT} method="post" onSubmit={onSubmit}>
      <label htmlFor="name">Name</label>
      <input id="name" name="name" autoComplete="name" required />
      <label htmlFor="email">Email</label>
      <input id="email" name="email" type="email" autoComplete="email" required />
      <label htmlFor="message">Message</label>
      <textarea id="message" name="message" rows={6} minLength={10} required />
      <input name="_gotcha" type="text" tabIndex={-1} autoComplete="off" hidden />
      {status.kind === "failed" ? (
        <div role="alert">
          {status.lines.map((line) => (
            <p key={line}>{line}</p>
          ))}
        </div>
      ) : null}
      <button disabled={status.kind === "sending"}>{status.kind === "sending" ? "Sending" : "Send message"}</button>
    </form>
  );
}

<script setup lang="ts">
import { computed, ref } from "vue";

const ENDPOINT = import.meta.env.VITE_IKIFORM_ENDPOINT;

const sending = ref(false);
const sent = ref(false);
const fields = ref<Record<string, string[]>>({});
const notice = ref("");
const firstError = computed(() => Object.values(fields.value)[0]?.[0] ?? notice.value);

async function send(event: SubmitEvent) {
  sending.value = true;
  try {
    const response = await fetch(ENDPOINT, {
      method: "POST",
      headers: { Accept: "application/json" },
      body: new FormData(event.target as HTMLFormElement),
    });
    const result = await response.json();
    sent.value = result.ok;
    fields.value = result.ok ? {} : (result.error.fields ?? {});
    notice.value = result.ok ? "" : result.error.message;
  } catch {
    notice.value = "Couldn't send. Check your connection and try again.";
  } finally {
    sending.value = false;
  }
}
</script>

<template>
  <p v-if="sent" role="status">Thanks. Your message is on its way, and I'll reply by email.</p>
  <form v-else :action="ENDPOINT" method="post" @submit.prevent="send">
    <label for="name">Name</label>
    <input id="name" name="name" autocomplete="name" required :aria-invalid="!!fields.name" />
    <label for="email">Email</label>
    <input id="email" name="email" type="email" autocomplete="email" required :aria-invalid="!!fields.email" />
    <label for="message">Message</label>
    <textarea id="message" name="message" rows="6" minlength="10" required :aria-invalid="!!fields.message" />
    <input name="_gotcha" type="text" tabindex="-1" autocomplete="off" hidden />
    <p v-if="firstError" role="alert">{{ firstError }}</p>
    <button :disabled="sending">{{ sending ? "Sending" : "Send message" }}</button>
  </form>
</template>