Faurm

faurm (pronounced like "form" or "foarm") is a simple library that aims to enhance the already great Remote Form from the even greater SvelteKit It's a form wrapper around SvelteKit preflight front-end validation. It adds DX niceties, namely timers, callbacks and more.

Before we begin

Remote form function are still in their infancy. This library's API, like the tech it depends on is subject to frequent breaking changes.

Installation

npm install faurm

Get Started

Write a schema of you file using any standard schema compliant library

// ./lib/schema.ts
import z from 'zod/v4';

export const createTodoFormSchema = z.object({
	title: z.string('The title field must be a string.').min(1, 'The title field is required')
});

Pass your schema to a remote form function.

// ./lib/todos.remote.ts
import { createTodoFormSchema } from './schema.js';
import { form } from '$app/server';

export const createTodo = form(createTodoFormSchema, (data) => {
	return {
		...data
	};
});

Enhance your form using the useFaurm wrapper.

<script lang="ts">
    import {createTodo} from "./lib/todos.remote.js";
    import {useFaurm} from "faurm";

    const form = useFaurm(createTodo, {
        initialData: {
            title: "A first todo"
        },
    })
    const {fields, enhance} = form;

</script>

<form {...enhance}>
    <label>
        Title
        <input {...fields.title.as('text')}
               aria-describedby={fields.title.issues() ? `invalid-title-helper` : null}/>
        {#if fields.title.issues() !== undefined }
            <small id={`invalid-title-helper`}>
                {(fields.title.issues() ?? []).map(i => i.message).join(', ')}
            </small>
        {/if}
    </label>

    <input type="submit" value="Create"/>
</form>


```sveltehtml
To enable front-end validation, pass your schema to the useFaurm wrapper
<script lang="ts">
    import {createTodo} from "./lib/todos.remote.js";
    import {useFaurm} from "faurm";
    import {createTodoFormSchema} from "./lib/schema.js";

    const form = useFaurm(createTodo, {
        validate: createTodoFormSchema,
        initialData: {
            title: "hello world"
        },
    })

    const {fields, enhance} = form;
</script>

<form {...enhance}>
    <label>
        Title
        <input {...fields.title.as('text')}
               aria-describedby={fields.title.issues() ? `invalid-title-helper` : null}/>
        {#if fields.title.issues() !== undefined }
            <small id={`invalid-title-helper`}>
                {(fields.title.issues() ?? []).map(i => i.message).join(', ')}
            </small>
        {/if}
    </label>


    <input type="submit" value="Create"/>
</form>

Event handlers allow you to react to your form submissions and their potential results

<script lang="ts">
    import {createTodo} from "./lib/todos.remote.js";
    import {useFaurm} from "faurm";

    const form = useFaurm(createTodo, {
        initialData: {
            title: "hello world"
        },
        onSubmit(data){
            console.log({submitted: data})
        },
        onValidationError(){
            console.log({issues: fields.title.issues()});
        },
        onSuccess(){
            console.log({result : createTodo.result});
        },
    })

    const {fields, enhance} = form;

</script>

<form {...enhance}>
    <label>
        Title
        <input {...fields.title.as('text')}
               aria-describedby={fields.title.issues() ? `invalid-title-helper` : null}/>
        {#if fields.title.issues() !== undefined }
            <small id={`invalid-title-helper`}>
                {(fields.title.issues() ?? []).map(i => i.message).join(', ')}
            </small>
        {/if}
    </label>
    <input type="submit" value="Create"/>
</form>

The timers object can be used to indicate loading state. You can use it to disable inputs, buttons or show messages !

<script lang="ts">
    import {createTodo} from "./lib/todos.remote.js";
    import {useFaurm} from "faurm";
    import {createTodoFormSchema} from "./lib/schema.js";

    const form = useFaurm(createTodo, {
        validate: createTodoFormSchema,
        initialData: {
            title: "hello world"
        },
        delay: 500,
        timeout: 3000
    })

    const {fields, enhance, timers} = form;
</script>

<form {...enhance}>
    <label>
        Title
        <input {...fields.title.as('text')}
               aria-describedby={fields.title.issues() ? `invalid-title-helper` : null}/>
        {#if fields.title.issues() !== undefined }
            <small id={`invalid-title-helper`}>
                {(fields.title.issues() ?? []).map(i => i.message).join(', ')}
            </small>
        {/if}
    </label>


    <input type="submit" value="{timers.submitting ? 'loading': 'Create'}"/>
    {#if timers.delayed}
        <p>Loading, with a small delay</p>
    {/if}

    {#if timers.timeout}
        <p>It's been 3 seconds already ? </p>
    {/if}
</form>

Share your form through svelte state with our helper type for a clean typed DX.

//./lib/context.svelte.ts
import type { InferFaurmContext } from 'faurm';
import { createTodos } from './todos.remote.js';
class TodosContext {
	form: InferFaurmContext<typeof createTodos>;
	//...

Features

• [x] Typesafe form enhancer with callbacks and timers
• [x] Integrate new Svelte Kit form functionalities ? Client driven single flight mutation could be used
• [x] Accessible components
• [ ] Extract constraints from our validation
• [ ] Draw the rest of the owl

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

License

MIT

Who are we ?

We are the French digital agency GRAUW. We love to build websites and apps, mainly using Laravel, Vue and SvelteKit. Feel free to reach out ! GRAUW.