From b9245234557cee1bbdf4c076f1bcf6c9641d6d2b Mon Sep 17 00:00:00 2001
From: Jon Staab <jstaab@protonmail.com>
Date: Fri, 25 Sep 2026 22:35:28 -0700
Subject: [PATCH] Make DragList generic over a key and reorder InputList and
 ImagesInput through it

---
 src/app/components/PrimaryNavSpaces.svelte |  2 +
 src/lib/components/DragList.svelte         | 49 +++++------
 src/lib/components/ImagesInput.svelte      | 94 +++++++++++-----------
 src/lib/components/InputList.svelte        | 80 +++++++++---------
 4 files changed, 114 insertions(+), 111 deletions(-)

diff --git a/src/app/components/PrimaryNavSpaces.svelte b/src/app/components/PrimaryNavSpaces.svelte
index 0cb6f33f..c0eee07b 100644
--- a/src/app/components/PrimaryNavSpaces.svelte
+++ b/src/app/components/PrimaryNavSpaces.svelte
@@ -1,5 +1,6 @@
 <script lang="ts">
   import cx from "classnames"
+  import {identity} from "@welshman/lib"
   import ImageIcon from "@lib/components/ImageIcon.svelte"
   import Divider from "@lib/components/Divider.svelte"
   import PrimaryNavItem from "@lib/components/PrimaryNavItem.svelte"
@@ -54,6 +55,7 @@
       <DragList
         class="flex flex-col items-center"
         items={$userSpaceUrls}
+        getKey={identity}
         onReorder={reorderSpaceUrls}>
         {#snippet item(url)}
           <PrimaryNavItemSpace {url} />
diff --git a/src/lib/components/DragList.svelte b/src/lib/components/DragList.svelte
index 1cb460e6..52a6c48c 100644
--- a/src/lib/components/DragList.svelte
+++ b/src/lib/components/DragList.svelte
@@ -1,14 +1,15 @@
-<script lang="ts">
+<script lang="ts" generics="T">
   import cx from "classnames"
   import type {Snippet} from "svelte"
   import {flip} from "svelte/animate"
   import {cubicOut} from "svelte/easing"
-  import {insertAt, removeAt} from "@welshman/lib"
+  import {equals, insertAt, removeAt} from "@welshman/lib"
 
   type Props = {
-    items: string[]
-    onReorder: (items: string[]) => void
-    item: Snippet<[string]>
+    items: T[]
+    getKey: (item: T) => string
+    onReorder: (items: T[]) => void
+    item: Snippet<[T]>
     class?: string
     itemClass?: string
     role?: string
@@ -17,6 +18,7 @@
 
   const {
     items,
+    getKey,
     onReorder,
     item,
     class: className = "",
@@ -25,20 +27,18 @@
     itemRole = undefined,
   }: Props = $props()
 
-  const isSameOrder = (a: string[], b: string[]) =>
-    a.length === b.length && a.every((item, index) => item === b[index])
-
   const moveTo = (source: string, target: string) => {
-    const from = order.indexOf(source)
-    const to = order.indexOf(target)
+    const keys = order.map(getKey)
+    const from = keys.indexOf(source)
+    const to = keys.indexOf(target)
 
     if (from >= 0 && to >= 0 && from !== to) {
       preview = insertAt(to, order[from], removeAt(from, order))
     }
   }
 
-  const onDragStart = (e: DragEvent, value: string) => {
-    dragged = value
+  const onDragStart = (e: DragEvent, key: string) => {
+    dragged = key
     dropped = false
 
     if (e.dataTransfer) {
@@ -50,19 +50,19 @@
     e.preventDefault()
   }
 
-  const onDragEnter = (e: DragEvent, value: string) => {
+  const onDragEnter = (e: DragEvent, key: string) => {
     e.preventDefault()
 
     if (dragged) {
-      moveTo(dragged, value)
+      moveTo(dragged, key)
     }
   }
 
-  const onDrop = (e: DragEvent, value: string) => {
+  const onDrop = (e: DragEvent, key: string) => {
     e.preventDefault()
 
     if (dragged) {
-      moveTo(dragged, value)
+      moveTo(dragged, key)
     }
 
     dragged = undefined
@@ -81,8 +81,8 @@
     dragged = undefined
   }
 
-  let preview = $state<string[] | undefined>()
-  let lastItems = $state<string[]>([])
+  let preview = $state.raw<T[] | undefined>()
+  let lastItems = $state.raw<T[]>([])
   let dragged = $state<string | undefined>()
   let dropped = $state(false)
 
@@ -91,7 +91,7 @@
 
   // The preview outlives the drop, since the caller takes a moment to publish the new order.
   $effect(() => {
-    if (!isSameOrder(items, lastItems)) {
+    if (!equals(items, lastItems)) {
       lastItems = items
       preview = undefined
     }
@@ -99,16 +99,17 @@
 </script>
 
 <div class={className} {role}>
-  {#each order as value (value)}
+  {#each order as value (getKey(value))}
+    {@const key = getKey(value)}
     <div
       animate:flip={{duration: 300, easing: cubicOut}}
-      class={cx("transition-opacity duration-200", itemClass, {"opacity-50": dragged === value})}
+      class={cx("transition-opacity duration-200", itemClass, {"opacity-50": dragged === key})}
       draggable="true"
       role={itemRole}
-      ondragstart={e => onDragStart(e, value)}
+      ondragstart={e => onDragStart(e, key)}
       ondragover={onDragOver}
-      ondragenter={e => onDragEnter(e, value)}
-      ondrop={e => onDrop(e, value)}
+      ondragenter={e => onDragEnter(e, key)}
+      ondrop={e => onDrop(e, key)}
       ondragend={onDragEnd}>
       {@render item(value)}
     </div>
diff --git a/src/lib/components/ImagesInput.svelte b/src/lib/components/ImagesInput.svelte
index 1ab9a469..21d62622 100644
--- a/src/lib/components/ImagesInput.svelte
+++ b/src/lib/components/ImagesInput.svelte
@@ -1,23 +1,28 @@
 <script lang="ts">
   import cx from "classnames"
-  import type {Maybe} from "@welshman/lib"
-  import {randomId} from "@welshman/lib"
-  import {removeAt, insertAt} from "@welshman/lib"
+  import {equals, randomId} from "@welshman/lib"
   import {preventDefault, stopPropagation} from "@lib/html"
   import CloseCircle from "@assets/icons/close-circle.svg?dataurl"
   import GallerySend from "@assets/icons/gallery-send.svg?dataurl"
   import Icon from "@lib/components/Icon.svelte"
   import Button from "@lib/components/Button.svelte"
+  import DragList from "@lib/components/DragList.svelte"
 
-  interface Props {
+  type Props = {
     value: (string | File)[]
     multiple?: boolean
   }
 
+  type Entry = {id: string; value: string | File}
+
   let {value = $bindable(), multiple = true}: Props = $props()
 
   const id = randomId()
 
+  const toEntry = (value: string | File) => ({id: randomId(), value})
+
+  const getKey = (entry: Entry) => entry.id
+
   const getImageUrl = (item: string | File): string => {
     if (typeof item === "string") {
       return item
@@ -25,15 +30,20 @@
     return URL.createObjectURL(item)
   }
 
+  const setEntries = (newEntries: Entry[]) => {
+    entries = newEntries
+    value = newEntries.map(entry => entry.value)
+  }
+
   const addFiles = (files: FileList | File[]) => {
-    const newFiles = Array.from(files).filter(file => file.type.startsWith("image/"))
+    const newEntries = Array.from(files)
+      .filter(file => file.type.startsWith("image/"))
+      .map(toEntry)
 
-    value = multiple ? [...value, ...newFiles] : newFiles.slice(0, 1)
+    setEntries(multiple ? [...entries, ...newEntries] : newEntries.slice(0, 1))
   }
 
-  const removeItem = (index: number) => {
-    value = removeAt(index, value)
-  }
+  const removeItem = (id: string) => setEntries(entries.filter(entry => entry.id !== id))
 
   const onFileChange = (e: Event) => {
     const target = e.target as HTMLInputElement
@@ -63,55 +73,47 @@
     dropActive = false
   }
 
-  let draggedIndex: Maybe<number> = $state()
+  // Urls can repeat, so each image carries an id to key it by.
+  let entries = $state.raw(value.map(toEntry))
   let dropActive = $state(false)
 
-  const handleDragStart = (e: DragEvent, index: number) => {
-    draggedIndex = index
-
-    if (e.dataTransfer) {
-      e.dataTransfer.effectAllowed = "move"
+  $effect(() => {
+    if (
+      !equals(
+        value,
+        entries.map(entry => entry.value),
+      )
+    ) {
+      entries = value.map(toEntry)
     }
-  }
-
-  const handleDragOver = (e: DragEvent, index: number) => {
-    e.preventDefault()
-
-    if (draggedIndex !== undefined && draggedIndex !== index) {
-      value = insertAt(index, value[draggedIndex], removeAt(draggedIndex, value))
-      draggedIndex = index
-    }
-  }
-
-  const handleDragEnd = () => {
-    draggedIndex = undefined
-  }
+  })
 </script>
 
 <div class="flex flex-col gap-2">
   <div class={cx("grid gap-3", multiple ? "grid-cols-3" : "grid-cols-1")} role="list">
-    {#each value as item, index (index)}
-      <div
-        class={cx(
-          "border-line bg-surface-more relative overflow-hidden rounded-2xl border border-solid",
-          multiple ? "aspect-square cursor-move" : "aspect-video",
-        )}
-        style:border-color={draggedIndex === index ? "var(--primary)" : undefined}
-        draggable={multiple}
-        role="listitem"
-        aria-label={multiple ? "Draggable image" : "Image"}
-        ondragstart={e => handleDragStart(e, index)}
-        ondragover={e => handleDragOver(e, index)}
-        ondragend={handleDragEnd}>
-        <img src={getImageUrl(item)} alt="Upload preview" class="h-full w-full object-cover" />
+    <DragList
+      class="contents"
+      itemClass={cx(
+        "border-line bg-surface-more relative overflow-hidden rounded-2xl border border-solid",
+        multiple ? "aspect-square cursor-move" : "aspect-video",
+      )}
+      itemRole="listitem"
+      items={entries}
+      {getKey}
+      onReorder={setEntries}>
+      {#snippet item(entry)}
+        <img
+          src={getImageUrl(entry.value)}
+          alt="Upload preview"
+          class="h-full w-full object-cover" />
         <Button
           aria-label="Remove image"
           class="button button-neutral button-xs button-circle bg-surface absolute right-1 top-1"
-          onclick={() => removeItem(index)}>
+          onclick={() => removeItem(entry.id)}>
           <Icon icon={CloseCircle} size={4} />
         </Button>
-      </div>
-    {/each}
+      {/snippet}
+    </DragList>
     {#if multiple || value.length === 0}
       <label
         for={id}
diff --git a/src/lib/components/InputList.svelte b/src/lib/components/InputList.svelte
index 6f3f45a6..75d0d00f 100644
--- a/src/lib/components/InputList.svelte
+++ b/src/lib/components/InputList.svelte
@@ -1,8 +1,8 @@
 <script lang="ts">
   import type {Snippet} from "svelte"
-  import type {Maybe} from "@welshman/lib"
-  import {append, removeAt, replaceAt, insertAt} from "@welshman/lib"
+  import {append, equals, randomId} from "@welshman/lib"
   import Button from "@lib/components/Button.svelte"
+  import DragList from "@lib/components/DragList.svelte"
   import TrashBin2 from "@assets/icons/trash-bin-2.svg?dataurl"
   import HamburgerMenu from "@assets/icons/hamburger-menu.svg?dataurl"
   import AddCircle from "@assets/icons/add-circle.svg?dataurl"
@@ -14,71 +14,69 @@
     placeholder?: string
   }
 
+  type Entry = {id: string; value: string}
+
   let {
     value = $bindable(),
     addLabel,
     placeholder = "Enter text...",
     allowAdd = true,
   }: Props & {allowAdd?: boolean} = $props()
-  let draggedIndex: Maybe<number> = $state()
 
-  const onChange = (newValue: string[]) => {
-    value = newValue
+  const toEntry = (value: string) => ({id: randomId(), value})
+
+  const getKey = (entry: Entry) => entry.id
+
+  const setEntries = (newEntries: Entry[]) => {
+    entries = newEntries
+    value = newEntries.map(entry => entry.value)
   }
 
-  const addItem = () => onChange(append("", value))
+  const addItem = () => setEntries(append(toEntry(""), entries))
 
-  const removeItem = (index: number) => onChange(removeAt(index, value))
+  const removeItem = (id: string) => setEntries(entries.filter(entry => entry.id !== id))
 
-  const updateItem = (index: number, item: string) => onChange(replaceAt(index, item, value))
+  const updateItem = (id: string, text: string) =>
+    setEntries(entries.map(entry => (entry.id === id ? {id, value: text} : entry)))
 
-  const handleDragStart = (e: DragEvent, index: number) => {
-    draggedIndex = index
+  // Strings can be empty or repeated, so each one carries an id to key it by.
+  let entries = $state.raw(value.map(toEntry))
 
-    if (e.dataTransfer) {
-      e.dataTransfer.effectAllowed = "move"
+  $effect(() => {
+    if (
+      !equals(
+        value,
+        entries.map(entry => entry.value),
+      )
+    ) {
+      entries = value.map(toEntry)
     }
-  }
-
-  const handleDragOver = (e: DragEvent, index: number) => {
-    e.preventDefault()
-
-    if (draggedIndex !== undefined && draggedIndex !== index) {
-      onChange(insertAt(index, value[draggedIndex], removeAt(draggedIndex, value)))
-      draggedIndex = index
-    }
-  }
-
-  const handleDragEnd = () => {
-    draggedIndex = undefined
-  }
+  })
 </script>
 
 <div class="flex flex-col gap-2" role="list">
-  <!-- eslint-disable-next-line svelte/require-each-key -->
-  {#each value as item, index}
-    <div
-      class="flex items-center gap-2"
-      draggable="true"
-      role="listitem"
-      aria-label="Draggable item"
-      ondragstart={e => handleDragStart(e, index)}
-      ondragover={e => handleDragOver(e, index)}
-      ondragend={handleDragEnd}>
-      <Button onclick={() => removeItem(index)}>
+  <DragList
+    class="contents"
+    itemClass="flex items-center gap-2"
+    itemRole="listitem"
+    items={entries}
+    {getKey}
+    onReorder={setEntries}>
+    {#snippet item(entry)}
+      <Button onclick={() => removeItem(entry.id)}>
         <Icon icon={TrashBin2} />
       </Button>
       <input
         type="text"
         class="input w-full"
-        value={item}
+        value={entry.value}
         {placeholder}
-        oninput={e => updateItem(index, e.currentTarget.value)} />
+        oninput={e => updateItem(entry.id, e.currentTarget.value)} />
       <div class="cursor-move" role="button" aria-label="Drag handle">
         <Icon icon={HamburgerMenu} />
       </div>
-    </div>
-  {/each}
+    {/snippet}
+  </DragList>
   {#if allowAdd}
     <Button class="button button-link w-fit px-0" onclick={addItem}>
       <Icon icon={AddCircle} size={5} />