From fb221cb861ec0064f6e9b5e5d6205bb229f401e5 Mon Sep 17 00:00:00 2001
From: Diego Imbert <diego@windmill.dev>
Date: Mon, 11 May 2026 11:46:55 +0200
Subject: [PATCH] feat(frontend): add UserDraft service for per-workspace local
 drafts

Introduces UserDraft, a key-value store keyed by
`{workspace}/{itemKind}/{path}` and backed by localStorage. Supports
save/get/remove plus a reactive use() handle so multiple component
instances observing the same draft stay in sync via a shared $state
loaded through useLocalStorageValue. Designed to host drafts for
scripts, flows, apps, raw apps, resources, variables, and all trigger
kinds.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 frontend/src/lib/userDraft.svelte.ts | 172 +++++++++++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 frontend/src/lib/userDraft.svelte.ts

diff --git a/frontend/src/lib/userDraft.svelte.ts b/frontend/src/lib/userDraft.svelte.ts
new file mode 100644
index 0000000000..a952c7583e
--- /dev/null
+++ b/frontend/src/lib/userDraft.svelte.ts
@@ -0,0 +1,172 @@
+import { get } from 'svelte/store'
+import { onDestroy } from 'svelte'
+import { workspaceStore } from './stores'
+import { useLocalStorageValue } from './svelte5Utils.svelte'
+
+export type UserDraftItemKind =
+	| 'script'
+	| 'flow'
+	| 'app'
+	| 'raw_app'
+	| 'resource'
+	| 'variable'
+	| 'schedule'
+	| 'webhook'
+	| 'default_email'
+	| 'email'
+	| 'http'
+	| 'websocket'
+	| 'postgres'
+	| 'kafka'
+	| 'nats'
+	| 'mqtt'
+	| 'sqs'
+	| 'gcp'
+	| 'azure'
+	| 'poll'
+	| 'cli'
+	| 'nextcloud'
+	| 'google'
+	| 'github'
+
+export type UserDraftOptions = {
+	workspace?: string
+}
+
+type DraftState<V> = { val: V | undefined }
+
+type DraftEntry = {
+	count: number
+	state: DraftState<unknown>
+}
+
+const entries = new Map<string, DraftEntry>()
+
+function resolveWorkspace(opts?: UserDraftOptions): string {
+	const ws = opts?.workspace ?? get(workspaceStore)
+	if (!ws) {
+		throw new Error(
+			'UserDraft: no workspace available (pass opts.workspace or set $workspaceStore)'
+		)
+	}
+	return ws
+}
+
+function mapKey(workspace: string, itemKind: UserDraftItemKind, path: string): string {
+	return `${workspace}/${itemKind}/${path}`
+}
+
+function localStorageKey(workspace: string, itemKind: UserDraftItemKind, path: string): string {
+	return `userdraft/w/${workspace}/${itemKind}/${path}`
+}
+
+export type UserDraftHandle<V> = {
+	get draft(): V | undefined
+	set draft(value: V | undefined)
+}
+
+export const UserDraft = {
+	save<V>(itemKind: UserDraftItemKind, path: string, value: V, opts?: UserDraftOptions): void {
+		const ws = resolveWorkspace(opts)
+		const mk = mapKey(ws, itemKind, path)
+		const entry = entries.get(mk)
+		if (entry) {
+			// Update the shared reactive state so all observers are notified.
+			entry.state.val = value
+			return
+		}
+		try {
+			localStorage.setItem(localStorageKey(ws, itemKind, path), JSON.stringify(value))
+		} catch (e) {
+			console.error('UserDraft.save: localStorage write failed', e)
+		}
+	},
+
+	get<V = unknown>(
+		itemKind: UserDraftItemKind,
+		path: string,
+		opts?: UserDraftOptions
+	): V | undefined {
+		const ws = resolveWorkspace(opts)
+		const mk = mapKey(ws, itemKind, path)
+		const entry = entries.get(mk)
+		if (entry) {
+			return entry.state.val as V | undefined
+		}
+		try {
+			const raw = localStorage.getItem(localStorageKey(ws, itemKind, path))
+			if (raw == null || raw === 'undefined') return undefined
+			return JSON.parse(raw) as V
+		} catch (e) {
+			console.error('UserDraft.get: localStorage read failed', e)
+			return undefined
+		}
+	},
+
+	remove(itemKind: UserDraftItemKind, path: string, opts?: UserDraftOptions): void {
+		const ws = resolveWorkspace(opts)
+		const mk = mapKey(ws, itemKind, path)
+		const lk = localStorageKey(ws, itemKind, path)
+		const entry = entries.get(mk)
+		if (entry) {
+			// Notify observers via the shared state setter.
+			entry.state.val = undefined
+		}
+		try {
+			// Always remove (the setter above would persist "undefined" as a string).
+			localStorage.removeItem(lk)
+		} catch (e) {
+			console.error('UserDraft.remove: localStorage remove failed', e)
+		}
+	},
+
+	use<V = unknown>(
+		itemKind: UserDraftItemKind,
+		path: string,
+		opts?: UserDraftOptions
+	): UserDraftHandle<V> {
+		const ws = resolveWorkspace(opts)
+		const mk = mapKey(ws, itemKind, path)
+		const lk = localStorageKey(ws, itemKind, path)
+
+		let entry = entries.get(mk)
+		if (!entry) {
+			entry = { count: 1, state: useLocalStorageValue<unknown>(lk, undefined) }
+			entries.set(mk, entry)
+		} else {
+			entry.count++
+		}
+
+		const sharedEntry = entry
+
+		onDestroy(() => {
+			const e = entries.get(mk)
+			if (!e) return
+			e.count--
+			if (e.count <= 0) {
+				entries.delete(mk)
+			}
+		})
+
+		return {
+			get draft(): V | undefined {
+				return sharedEntry.state.val as V | undefined
+			},
+			set draft(value: V | undefined) {
+				sharedEntry.state.val = value
+				if (value === undefined) {
+					try {
+						localStorage.removeItem(lk)
+					} catch (e) {
+						console.error('UserDraft.use: localStorage remove failed', e)
+					}
+				}
+			}
+		}
+	}
+}
+
+/** Test-only: clear all in-memory entries. */
+export function __resetUserDraftForTesting(): void {
+	entries.clear()
+}