customRequest added to onSubmit

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - New validation library: [Superstruct](https://docs.superstructjs.org/)!
+- `customRequest` added to the [onSubmit](https://superforms.rocks/concepts/events#onsubmit) options, that lets you use a custom [fetch](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) or [XMLHttpRequest](https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest) when submitting the form. Very useful for progress bars when uploading large files.
 
 ### Fixed
 

src/lib/client/superForm.ts

@@ -25,7 +25,7 @@ import {
 import { beforeNavigate, goto, invalidateAll } from '$app/navigation';
 import { SuperFormError, flattenErrors, mapErrors, updateErrors } from '$lib/errors.js';
 import { cancelFlash, shouldSyncFlash } from './flash.js';
-import { applyAction, enhance as kitEnhance } from '$app/forms';
+import { applyAction, deserialize, enhance as kitEnhance } from '$app/forms';
 import { setCustomValidityForm, updateCustomValidity } from './customValidity.js';
 import { inputInfo } from './elements.js';
 import { Form as HtmlForm, scrollToFirstError } from './form.js';
@@ -105,6 +105,13 @@ export type FormOptions<
 			 * Override client validation temporarily for this form submission.
 			 */
 			validators: (validators: Exclude<ValidatorsOption<T>, 'clear'>) => void;
+			/**
+			 * Use a custom fetch or XMLHttpRequest implementation for this form submission. It must return an ActionResult in the response body.
+			 * If the request is using a XMLHttprequest, the promise must be resolved when the request is complete.
+			 */
+			customRequest: (
+				validators: (input: Parameters<SubmitFunction>[0]) => Promise<Response | XMLHttpRequest>
+			) => void;
 		}
 	) => MaybePromise<unknown | void>;
 	onResult: (event: {
@@ -1588,10 +1595,14 @@ export function superForm<
 		);
 
 		let currentRequest: AbortController | null;
+		let customRequest:
+			| ((input: Parameters<SubmitFunction>[0]) => Promise<Response | XMLHttpRequest>)
+			| undefined = undefined;
 
 		return kitEnhance(FormElement, async (submitParams) => {
 			let jsonData: Record<string, unknown> | undefined = undefined;
 			let validationAdapter = options.validators;
+			undefined;
 
 			const submit = {
 				...submitParams,
@@ -1603,8 +1614,11 @@ export function superForm<
 				},
 				validators(adapter: Exclude<ValidatorsOption<T>, 'clear'>) {
 					validationAdapter = adapter;
+				},
+				customRequest(request: typeof customRequest) {
+					customRequest = request;
 				}
-			};
+			} satisfies Parameters<NonNullable<FormOptions<T, M>['onSubmit']>>[0];
 
 			const _submitCancel = submit.cancel;
 			let cancelled = false;
@@ -1959,6 +1973,18 @@ export function superForm<
 				unsubCheckforNav();
 			}
 
+			if (customRequest) {
+				if (!cancelled) _submitCancel();
+				const response = await customRequest(submitParams);
+				const result: ActionResult =
+					response instanceof Response
+						? deserialize(await response.text())
+						: deserialize(response.responseText);
+
+				if (result.type === 'error') result.status = response.status;
+				validationResponse({ result });
+			}
+
 			return validationResponse;
 		});
 	}

src/routes/(v2)/v2/customrequest/+page.server.ts

@@ -0,0 +1,23 @@
+import { superValidate, message, withFiles } from '$lib/index.js';
+import { zod } from '$lib/adapters/zod.js';
+import { fail } from '@sveltejs/kit';
+import { schema } from './schema.js';
+
+export const load = async () => {
+	const form = await superValidate(zod(schema));
+	return { form };
+};
+
+export const actions = {
+	default: async ({ request }) => {
+		const formData = await request.formData();
+		console.log(formData);
+
+		const form = await superValidate(formData, zod(schema), { allowFiles: true });
+		console.log(form);
+
+		if (!form.valid) return fail(400, withFiles({ form }));
+
+		return message(form, 'Form posted successfully!');
+	}
+};

src/routes/(v2)/v2/customrequest/+page.svelte

@@ -0,0 +1,112 @@
+<script lang="ts">
+	import { page } from '$app/stores';
+	import { superForm } from '$lib/index.js';
+	import SuperDebug from '$lib/index.js';
+	import FileInput from './FileInput.svelte';
+	import type { PageData } from './$types.js';
+	import type { SubmitFunction } from '@sveltejs/kit';
+
+	export let data: PageData;
+	let progress = 0;
+
+	function fileUploadWithProgressbar(input: Parameters<SubmitFunction>[0]) {
+		return new Promise<XMLHttpRequest>((res) => {
+			let xhr = new XMLHttpRequest();
+
+			// listen for upload progress
+			xhr.upload.onprogress = function (event) {
+				progress = Math.round((100 * event.loaded) / event.total);
+				console.log(`File is ${progress}% uploaded.`);
+			};
+
+			// handle error
+			xhr.upload.onerror = function () {
+				console.log(`Error during the upload: ${xhr.status}.`);
+			};
+
+			// upload completed successfully
+			xhr.onload = function () {
+				if (xhr.readyState === xhr.DONE) {
+					console.log('Upload completed successfully.');
+					progress = 0;
+					res(xhr);
+				}
+			};
+
+			xhr.open('POST', input.action, true);
+			xhr.send(input.formData);
+
+			return xhr;
+		});
+	}
+
+	const { form, errors, message, enhance } = superForm(data.form, {
+		taintedMessage: null,
+		onSubmit({ customRequest }) {
+			customRequest(fileUploadWithProgressbar);
+		}
+	});
+	const acceptedExtensions = '.flac, .mp3';
+</script>
+
+<SuperDebug data={$form} />
+
+<h3>Superforms testing ground - Zod</h3>
+
+{#if $message}
+	<!-- eslint-disable-next-line svelte/valid-compile -->
+	<div class="status" class:error={$page.status >= 400} class:success={$page.status == 200}>
+		{$message}
+	</div>
+{/if}
+
+<form method="POST" enctype="multipart/form-data" use:enhance>
+	<FileInput
+		name="track"
+		label="Track"
+		accept={acceptedExtensions}
+		bind:value={$form.track}
+		errors={$errors.track}
+	/>
+	<br /><progress max="100" value={progress}>{progress}%</progress>
+
+	<div><button>Submit</button></div>
+</form>
+
+<hr />
+<p><a target="_blank" href="https://superforms.rocks/api">API Reference</a></p>
+
+<style>
+	.status {
+		color: white;
+		padding: 4px;
+		padding-left: 8px;
+		border-radius: 2px;
+		font-weight: 500;
+	}
+
+	.status.success {
+		background-color: seagreen;
+	}
+
+	.status.error {
+		background-color: #ff2a02;
+	}
+
+	a {
+		text-decoration: underline;
+	}
+
+	button {
+		margin-top: 1rem;
+	}
+
+	hr {
+		margin-top: 4rem;
+	}
+
+	form {
+		padding-top: 1rem;
+		padding-bottom: 1rem;
+	}
+</style>

src/routes/(v2)/v2/customrequest/FileInput.svelte

@@ -0,0 +1,36 @@
+<script lang="ts">
+	import type { InputConstraint } from '$lib/index.js';
+
+	export let value: File | File[] | null;
+	export let name: string;
+	export let label: string | undefined = undefined;
+	export let errors: string[] | undefined = undefined;
+	export let constraints: InputConstraint | undefined = undefined;
+
+	const input = (e: Event) => {
+		const file = (e.currentTarget as HTMLInputElement).files?.item(0) ?? null;
+		value = file;
+	};
+</script>
+
+<label for={name}>{label}</label>
+<input
+	{name}
+	id={name}
+	type="file"
+	on:change={input}
+	aria-invalid={errors ? 'true' : undefined}
+	{...constraints}
+	{...$$restProps}
+/>
+{#if errors}<span class="error">{errors}</span>{/if}
+
+<style>
+	.error {
+		color: red;
+	}
+
+	input {
+		margin-bottom: 0;
+	}
+</style>

src/routes/(v2)/v2/customrequest/schema.ts

@@ -0,0 +1,5 @@
+import { z } from 'zod';
+
+export const schema = z.object({
+	track: z.instanceof(File, { message: 'Please upload a file.' })
+});