date input: add labels, validation, fix NaN checking

src/lib/Dateinput.svelte

@@ -2,7 +2,9 @@
 	import { InputValidatorEvent, liveValidator, validate } from '@svelte-toolkit/validate';
 	import { CalendarBlank } from 'phosphor-svelte';
 	import { type Snippet } from 'svelte';
-	import type { ClassValue, FormEventHandler, KeyboardEventHandler } from 'svelte/elements';
+	import type { ClassValue, KeyboardEventHandler } from 'svelte/elements';
+	import { generateIdentifier } from './util.js';
+	import Label from './Label.svelte';
 
 	type FormatString = 'year' | 'month' | 'day';
 	const blankState = {
@@ -16,7 +18,9 @@
 		value?: Date;
 		min?: Date;
 		max?: Date;
+		label?: string;
 		required?: boolean;
+		invalidMessage?: string;
 		class?: ClassValue | undefined | null;
 		format?: FormatString[];
 	}
@@ -24,13 +28,19 @@
 	let {
 		name,
 		value = $bindable<Date | undefined>(),
+		/** min specifies lower bounds for the date input (WARNING: NOT IMPLEMENTED) */
 		min = new Date(1900, 0, 1),
+		/** max specifies upper bounds for the date input (WARNING: NOT IMPLEMENTED) */
 		max = new Date(2100, 11, 31),
+		label,
 		required = false,
+		invalidMessage = 'Valid date is required',
 		class: classList,
 		format = ['year', 'month', 'day']
 	}: Props = $props();
 
+	const id = $derived(generateIdentifier('dateinput', name));
+
 	const inputSnippets = $derived.by(() => {
 		const found: Partial<Record<FormatString, boolean>> = {};
 		const arr: Snippet[] = [];
@@ -56,11 +66,8 @@
 
 	let valid = $state(true);
 	let containerElement: HTMLDivElement;
-	let yearValid = $state(true);
 	let yearElement = $state<HTMLDivElement | null>(null);
-	let monthValid = $state(true);
 	let monthElement = $state<HTMLDivElement | null>(null);
-	let dayValid = $state(true);
 	let dayElement = $state<HTMLDivElement | null>(null);
 	let previousYearValue = $state<string | undefined>(undefined);
 	let yearValue = $derived.by(() => {
@@ -108,8 +115,8 @@
 					setPrevious();
 					previousYearValue = undefined;
 					value = undefined;
-					return;
 				}
+				return;
 			}
 		}
 
@@ -121,8 +128,8 @@
 					setPrevious();
 					previousMonthValue = undefined;
 					value = undefined;
-					return;
 				}
+				return;
 			}
 		}
 
@@ -134,8 +141,8 @@
 					setPrevious();
 					previousDayValue = undefined;
 					value = undefined;
-					return;
 				}
+				return;
 			}
 		}
 
@@ -193,7 +200,13 @@
 	};
 </script>
 
-<div
+<div>
+	<!-- Date input Label -->
+	{#if label}
+		<Label for={id}>{label}</Label>
+	{/if}
+
+	<div
 		bind:this={containerElement}
 		class={[
 			'inline-flex w-54 items-center justify-start gap-1',
@@ -203,8 +216,14 @@
 			!valid && 'border-red-500!',
 			classList
 		]}
->
-	<input type="hidden" {name} value={value?.toISOString() ?? ''} />
+	>
+		<input
+			type="hidden"
+			{name}
+			{id}
+			value={value?.toISOString() ?? ''}
+			use:validate={{ required }}
+		/>
 
 		{#each inputSnippets as snippet, i}
 			{@render snippet()}
@@ -215,6 +234,12 @@
 		{/each}
 
 		<CalendarBlank size="1.5em" class="ml-auto" />
+	</div>
+
+	<!-- Error message if invalid -->
+	<div class={['opacity-0 transition-opacity', !valid && 'opacity-100']}>
+		<Label for={id} error>{invalidMessage}</Label>
+	</div>
 </div>
 
 {#snippet year()}
@@ -235,7 +260,6 @@
 		}}
 		use:liveValidator={{ constrain: true }}
 		onvalidate={(e) => {
-			yearValid = e.detail.valid;
 			handleComponentValidate(e);
 		}}
 	></div>
@@ -259,7 +283,6 @@
 		}}
 		use:liveValidator={{ constrain: true }}
 		onvalidate={(e) => {
-			monthValid = e.detail.valid;
 			handleComponentValidate(e);
 		}}
 	></div>
@@ -283,7 +306,6 @@
 		}}
 		use:liveValidator={{ constrain: true }}
 		onvalidate={(e) => {
-			dayValid = e.detail.valid;
 			handleComponentValidate(e);
 		}}
 	></div>

src/lib/Label.svelte

@@ -15,7 +15,7 @@
 		'transition-fontColor block',
 		error && !bigError
 			? 'mt-1 text-sm font-normal text-red-500'
-			: 'text-text dark:text-background mb-3 text-base font-medium',
+			: 'text-text dark:text-background mb-2 text-base font-medium',
 		bigError && 'text-red-500!'
 	]}
 >