nerd-coder/svelte-zod-form

README

🌵 Svelte Zod Form

Building forms in Svelte with breeze, using Zod

Note

Currently upgrading to Svelte 5's Runes 🔥, stay tuned!

Example

REPL: Simple login form

Installation

NPM

npm i @nerd-coder/svelte-zod-form

JSR (Recommended)

npx jsr add @nerd-coder/svelte-zod-form

How to use

First you need to create a Zod's schema

import { z } from 'zod'

const loginSchema = z.object({
  email: z.string().email(),
  pass: z.string().min(4),
})

Then pass the schema to ZodFormStore:

const form = new ZodFormStore(loginSchema, { onSubmit: v => console.log('Submitted values:', v) })

All the field's handler, value will be generated and typed for you:

// We need pull the generated field store out, in order
// to use the Svelte's "auto subscription" feature "$"
const { email_value, email_error, email_dirty, pass_value, pass_error, pass_dirty } = form.stores

Finally, use it in html

<form on:submit|preventDefault={form.triggerSubmit}>
  <fieldset>
    <input
      name="email"
      on:input={form.fields.email.handleChange}
      on:blur={form.fields.email.handleBlur}
      value={$email_value || ''}
      class:invalid={!!$email_error}
      class:valid={!$email_error && !!$email_dirty}
    />
    {#if $email_error}<p>{$email_error}</p>{/if}
  </fieldset>

  <fieldset>
    <input
      name="pass"
      type="password"
      on:input={form.fields.pass.handleChange}
      on:blur={form.fields.pass.handleBlur}
      value={$pass_value || ''}
      class:invalid={!!$pass_error}
      class:valid={!$pass_error && !!$pass_dirty}
    />
    {#if $pass_error}<p>{$pass_error}</p>{/if}
  </fieldset>

  <button type="submit">Sign In</button>
</form>

Configuration

`initialValue`

type: Partial<T>
required: false
default: undefined

The initial data in the form. Will revert to this value if call form.reset.

const form = new ZodFormStore(schema, {
  initialValue: { email: 'my@email.com' },
  ...
})

`onSubmit`

type: (v: T) => Promise<void | string> | string | void
required: true

Async callback to handle submmition of the form. Should return nothing, or an string contain error message

const form = new ZodFormStore(schema, {
  onSubmit: (values) => console.log('Submitted values:', values),
  ...
})

`debug`

type: boolean
required: false
default: false

Print various debug messages.

const form = new ZodFormStore(schema, {
  debug: true,
  ...
})

API

Prop	Type	Description
model	`Readable<T>`	Form's data. Will be passed to onSubmit handler
options	`readonly ZodFormStoreOptions<T>`	Form settings. Should not be update
triggerSubmit	`() => Promise<void>`	Function to start parsing, validating and submit the form's data
setupAutoSubmit	`(delay: number) => Unsubscriber`	Setup auto submit on every change of the model
reset	`() => void`	Function to reset the form to original state.
submitting	`Readable<boolean>`	True of submitting the form.
error	`Readable<string>`	Error message returned from `onSubmit` handler, or custom validation message.
errors	`Readable<string[]>`	Array of string contains all error messages (including fields's errors and error return from `onSubmit` handler).
dirty	`Readable<boolean>`	Indicate if the form is edited or submitted.
valid	`Readable<boolean>`	Indicate if the form is valid.
fields	`object`	Generated fields's functions.
stores	`object`	Generated fields's stores.

Generated stores's props

Prop	Type	Description
stores.`fieldName`_value	`Readable<T['fieldName']>`	Readable store holding field's value
stores.`fieldName`_touched	`Readable<boolean>`	The field have been touched or not
stores.`fieldName`_dirty	`Readable<boolean>`	The field value been changed or not
stores.`fieldName`_error	`Readable<string>`	The field validation error message, if any
stores.`fieldName`_valid	`Readable<boolean>`	The field value is valid or not

Generated field's functions

Prop	Type	Description
fields.`fieldName`.updateValue	`(updater: Updater<T['fieldName']>) => void`	Function to update field's value
stores.`fieldName`.setValue	`(val: T['fieldName']) => void`	Function to set field's value
stores.`fieldName`.handleChange	`(val: unknown) => void`	Callback to update field's value
stores.`fieldName`.handleBlur	`() => void`	Callback to mark field as touched
stores.`fieldName`.reset	`() => void`	Reset field to original state
stores.`fieldName`.setError	`(msg: string) => void`	Manually set field error
stores.`fieldName`.setTouched	`(val: boolean) => void`	Manually set touched state

Features

Use Svelte native stores
Fine-grained reactivity (currently up to field level)
Validation using Zod (Peer dependencies)
TypeScript
Minimal

Extra

Why the cactus 🌵?

> For its resilience

TODO

More tests
Support nested object
Support array

Contributions

Any contributions are highly appreciate, please make a pull-request. If you would like to discuses a new feature, please create an issue first.