SvelteKit で見込み客を選別するリードフォームを作る

src/
  env.ts
  hooks.server.ts
  routes/
    contact-sales/
      +page.server.ts
      +page.svelte
      thanks/+page.svelte
vite.config.ts
.env

import { defineEnvVars } from "@sveltejs/kit/env";

export const variables = defineEnvVars({
  IKIFORM_SECRET_KEY: {},
});

import type { Handle } from "@sveltejs/kit/hooks";

const TAGS = ["utm_source", "utm_medium", "utm_campaign"];

export const handle: Handle = async ({ event, resolve }) => {
  if (event.request.method === "GET" && !event.cookies.get("lead_source")) {
    const referer = event.request.headers.get("referer") ?? "";
    const from = URL.canParse(referer) ? new URL(referer) : null;
    const external = from && from.host !== event.url.host ? from.href.slice(0, 300) : "";
    const source = new URLSearchParams();
    for (const tag of TAGS) source.set(tag, event.url.searchParams.get(tag)?.slice(0, 100) ?? "");

    if (external || TAGS.some((tag) => source.get(tag))) {
      source.set("referrer", external);
      source.set("landing_page", event.url.pathname.slice(0, 200));
      event.cookies.set("lead_source", source.toString(), {
        path: "/",
        httpOnly: true,
        sameSite: "lax",
        maxAge: 60 * 60 * 24 * 30,
      });
    }
  }
  return resolve(event);
};

import { fail, redirect } from "@sveltejs/kit";
import { IKIFORM_SECRET_KEY } from "$app/env/private";
import * as v from "valibot";
import type { Actions } from "./$types";

export const prerender = false;

const Lead = v.object({
  name: v.pipe(v.string(), v.trim(), v.nonEmpty("Tell us who to reply to."), v.maxLength(120)),
  email: v.pipe(v.string(), v.trim(), v.email("Enter a work email we can reply to.")),
  company: v.pipe(v.string(), v.trim(), v.nonEmpty("Which company is this for?"), v.maxLength(200)),
  company_size: v.picklist(["1_10", "11_50", "51_200", "201_1000", "1000_plus"], "Pick a company size."),
  budget: v.picklist(["under_10k", "10k_50k", "50k_plus", "unsure"], "Pick a budget range."),
  timeline: v.picklist(["this_quarter", "next_quarter", "later", "researching"], "Pick a timeline."),
  message: v.pipe(v.string(), v.trim(), v.maxLength(5000, "Keep it under 5,000 characters.")),
  _gotcha: v.string(),
});

const SOURCE = ["utm_source", "utm_medium", "utm_campaign", "referrer", "landing_page"];

export const actions = {
  default: async ({ request, cookies, fetch, url }) => {
    const form = await request.formData();
    const values = Object.fromEntries(Object.keys(Lead.entries).map((key) => [key, String(form.get(key) ?? "")]));
    const parsed = v.safeParse(Lead, values);
    if (!parsed.success) {
      const nested = v.flatten<typeof Lead>(parsed.issues).nested ?? {};
      const errors = Object.fromEntries(Object.entries(nested).map(([key, list]) => [key, list?.[0] ?? ""]));
      return fail(400, { errors, values });
    }

    const lead = parsed.output;
    const stored = new URLSearchParams(cookies.get("lead_source") ?? "");
    const qualified =
      lead.company_size !== "1_10" &&
      (lead.budget === "10k_50k" || lead.budget === "50k_plus") &&
      (lead.timeline === "this_quarter" || lead.timeline === "next_quarter");

    const response = await fetch("https://ikiform.com/f/frm_xxxxxxxxxxxxxxxx", {
      method: "POST",
      headers: {
        Accept: "application/json",
        "Content-Type": "application/json",
        Authorization: `Bearer ${IKIFORM_SECRET_KEY}`,
        Origin: request.headers.get("origin") ?? url.origin,
      },
      body: JSON.stringify({
        ...lead,
        ...Object.fromEntries(SOURCE.map((key) => [key, stored.get(key) ?? ""])),
        fit: qualified ? "qualified" : "nurture",
      }),
    });
    const result = await response.json().catch(() => null);
    if (!result?.ok) {
      const fields: Record<string, string[]> = result?.error?.fields ?? {};
      const errors = Object.fromEntries(Object.entries(fields).map(([key, list]) => [key, list[0] ?? ""]));
      if (!Object.keys(errors).length) errors.form = "We couldn't send that. Email sales@example.com instead.";
      return fail(response.status >= 400 ? response.status : 502, { errors, values });
    }

    if (!qualified || lead._gotcha) redirect(303, "/contact-sales/thanks");
    redirect(303, `https://cal.com/acme/intro?${new URLSearchParams({ name: lead.name, email: lead.email })}`, { external: true });
  },
} satisfies Actions;

<script lang="ts">
  import { enhance } from "$app/forms";
  import type { PageProps } from "./$types";

  let { form }: PageProps = $props();
  let pending = $state(false);
  const errors = $derived<Record<string, string | undefined>>(form?.errors ?? {});
  const values = $derived<Record<string, string | undefined>>(form?.values ?? {});

  const selects = [
    { id: "company_size", label: "Company size", options: [["1_10", "1 to 10"], ["11_50", "11 to 50"], ["51_200", "51 to 200"], ["201_1000", "201 to 1,000"], ["1000_plus", "More than 1,000"]] },
    { id: "budget", label: "Budget", options: [["under_10k", "Under $10k"], ["10k_50k", "$10k to $50k"], ["50k_plus", "More than $50k"], ["unsure", "Not sure yet"]] },
    { id: "timeline", label: "When do you want to start?", options: [["this_quarter", "This quarter"], ["next_quarter", "Next quarter"], ["later", "Later this year"], ["researching", "Researching for now"]] },
  ];
</script>

<form
  method="POST"
  use:enhance={() => {
    pending = true;
    return async ({ update }) => {
      await update({ reset: false });
      pending = false;
    };
  }}
>
  <label for="name">Name</label>
  <input id="name" name="name" autocomplete="name" required value={values.name ?? ""} />
  {#if errors.name}<p role="alert">{errors.name}</p>{/if}

  <label for="email">Work email</label>
  <input id="email" name="email" type="email" autocomplete="email" required value={values.email ?? ""} />
  {#if errors.email}<p role="alert">{errors.email}</p>{/if}

  <label for="company">Company</label>
  <input id="company" name="company" autocomplete="organization" required value={values.company ?? ""} />
  {#if errors.company}<p role="alert">{errors.company}</p>{/if}

  {#each selects as select (select.id)}
    <label for={select.id}>{select.label}</label>
    <select id={select.id} name={select.id} required value={values[select.id] ?? ""}>
      <option value="" disabled>Choose one</option>
      {#each select.options as [value, text] (value)}
        <option {value}>{text}</option>
      {/each}
    </select>
    {#if errors[select.id]}<p role="alert">{errors[select.id]}</p>{/if}
  {/each}

  <label for="message">Anything we should know?</label>
  <textarea id="message" name="message" rows="4">{values.message ?? ""}</textarea>

  <input name="_gotcha" type="text" tabindex="-1" autocomplete="off" hidden />
  {#if errors.form}<p role="alert">{errors.form}</p>{/if}
  <button disabled={pending}>{pending ? "Sending" : "Talk to sales"}</button>
</form>