Introduction
What is this?
Formsnap takes the already incredible sveltekit-superforms (winner of Svelte Hack 2023 for best library), made by the brilliant Andreas Söderlund and wraps it with components that make it simpler to use while making your forms accessible by default.
The Same Form, Two Ways
To showcase the value provided by Formsnap, let's take a look at a simple sign up form using only Superforms, and then using Superforms with Formsnap.
Superforms Only
<script lang="ts">
import type { PageData } from "./$types";
import { superForm } from "sveltekit-superforms";
import { zodClient } from "sveltekit-superforms/adapters";
import { signupFormSchema } from "./schema";
let { data } = $props();
const { form, errors, enhance, constraints } = superForm(data.form, {
validators: zodClient(signupFormSchema),
});
</script>
<form method="POST" use:enhance>
<label for="name">Name</label>
<input
id="name"
name="name"
aria-describedby={$errors.name ? "name-error name-desc" : "name-desc"}
aria-invalid={$errors.name ? "true" : undefined}
aria-required={$constraints.name?.required ? "true" : undefined}
bind:value={$form.name}
/>
<span id="name-desc">Be sure to use your real name.</span>
<span id="name-error" aria-live="assertive">
{#if $errors.name.length}
{#each $errors.name as err}
{err}
{/each}
{/if}
</span>
<label for="email">Email</label>
<input
id="email"
name="email"
type="email"
aria-describedby={$errors.email ? "email-error email-desc" : "email-desc"}
aria-invalid={$errors.email ? "true" : undefined}
aria-required={$constraints.email?.required ? "true" : undefined}
bind:value={$form.email}
/>
<span id="email-desc">It's preferred that you use your company email.</span>
<span id="email-error" aria-live="assertive">
{#if $errors.email.length}
{#each $errors.email as err}
{err}
{/each}
{/if}
</span>
<label for="password">Password</label>
<input
id="password"
name="password"
type="password"
aria-describedby={$errors.password ? "password-error password-desc" : "password-desc"}
aria-invalid={$errors.password ? "true" : undefined}
aria-required={$constraints.password?.required ? "true" : undefined}
bind:value={$form.password}
/>
<span id="password-desc">Ensure the password is at least 10 characters.</span>
<span id="password-error" aria-live="assertive">
{#if $errors.password.length}
{#each $errors.password as err}
{err}
{/each}
{/if}
</span>
<button>Submit</button>
</form>
That's quite a bit of code required to get a simple, accessible form up and running. We can't move as quickly as we'd like to, it's not very DRY, and is ripe for copy-paste errors.
All is not lost though, as the whole idea behind Formsnap is to make this process simpler, without sacrificing the flexibility that Superforms provides.
Superforms + Formsnap
<script lang="ts">
import { Field, Control, Label, FieldErrors, Description } from "formsnap";
import { signupFormSchema } from "./schema.ts";
import { zodClient } from "sveltekit-superforms/adapters";
import { superForm } from "sveltekit-superforms";
let { data } = $props();
const form = superForm(data.form, {
validators: zodClient(signupFormSchema),
});
const { form: formData, enhance } = form;
</script>
<form method="POST" use:enhance>
<Field {form} name="name">
<Control>
{#snippet children({ props })}
<Label>Name</Label>
<input {...props} bind:value={$formData.name} />
{/snippet}
</Control>
<Description>Be sure to use your real name.</Description>
<FieldErrors />
</Field>
<Field {form} name="email">
<Control>
{#snippet children({ props })}
<Label>Email</Label>
<input {...props} type="email" bind:value={$formData.email} />
{/snippet}
</Control>
<Description>It's preferred that you use your company email.</Description>
<FieldErrors />
</Field>
<Field {form} name="password">
<Control>
{#snippet children({ props })}
<Label>Password</Label>
<input {...props} type="password" bind:value={$formData.password} />
{/snippet}
</Control>
<Description>Ensure the password is at least 10 characters.</Description>
<FieldErrors />
</Field>
</form>
That's it! We just condensed a bunch of code, while retaining the same functionality.
Next Steps
To get started using Formsnap, head over to the Quick start section of the docs, where you'll learn how to install and use the library.