feat(sidebar): provide a proxy for the files sidebar

__tests__/sidebar/sidebarTab.spec.ts

@@ -6,7 +6,7 @@
 import type { IFolder, INode, IView } from '../../lib/index.ts'
 
 import { beforeEach, describe, expect, it, Mock, vi } from 'vitest'
-import { getSidebarTabs, ISidebarTab, registerSidebarTab } from '../../lib/sidebar'
+import { getSidebarTabs, ISidebarTab, registerSidebarTab } from '../../lib/sidebar/SidebarTab.ts'
 // missing in JSDom but supported by every browser!
 import 'css.escape'
 

lib/sidebar/Sidebar.ts

@@ -0,0 +1,92 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import type { ISidebarContext, ISidebarTab } from './SidebarTab.ts'
+
+import { getSidebarTabs, registerSidebarTab } from './SidebarTab.ts'
+
+export interface ISidebar {
+	/**
+	 * If the files sidebar can currently be accessed.
+	 * Registering tabs also works if the sidebar is currently not available.
+	 */
+	readonly available: boolean
+
+	/**
+	 * The current open state of the sidebar
+	 */
+	readonly open: boolean
+
+	/**
+	 * Open or close the sidebar
+	 *
+	 * @param open - The new open state
+	 */
+	setOpen(open: boolean): void
+
+	/**
+	 * Register a new sidebar tab
+	 *
+	 * @param tab - The sidebar tab to register
+	 */
+	registerTab(tab: ISidebarTab): void
+
+	/**
+	 * Get all registered sidebar tabs.
+	 * If a node is passed only the enabled tabs are retrieved.
+	 */
+	getTabs(context?: ISidebarContext): ISidebarTab[]
+}
+
+/**
+ * This is just a proxy allowing an arbitrary `@nextcloud/files` library version to access the defined interface of the sidebar.
+ * By proxying this instead of providing the implementation here we ensure that if apps use different versions of the library,
+ * we do not end up with version conflicts between them.
+ *
+ * If we add new properties they just will be available in new library versions.
+ * If we decide to do a breaking change we can either add compatibility wrappers in the implementation in the files app.
+ */
+class SidebarProxy implements ISidebar {
+
+	get available(): boolean {
+		return !!window.OCA?.Files?.Sidebar
+	}
+
+	get open(): boolean {
+		return !!window.OCA?.Files?.Sidebar?.state.file
+	}
+
+	setOpen(open: boolean): void {
+		if (open) {
+			window.OCA?.Files?.Sidebar?.open()
+		} else {
+			window.OCA?.Files?.Sidebar?.close()
+		}
+	}
+
+	setActiveTab(tabId: string): void {
+		window.OCA?.Files?.Sidebar?.setActiveTab(tabId)
+	}
+
+	registerTab(tab: ISidebarTab): void {
+		registerSidebarTab(tab)
+	}
+
+	getTabs(context?: ISidebarContext): ISidebarTab[] {
+		const tabs = getSidebarTabs()
+		if (context) {
+			return tabs.filter((tab) => tab.enabled(context))
+		}
+		return tabs
+	}
+
+}
+
+/**
+ * Get a reference to the files sidebar.
+ */
+export function getSidebar(): ISidebar {
+	return new SidebarProxy()
+}

lib/sidebar/SidebarTab.ts

@@ -0,0 +1,163 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import type { IView } from '../navigation/view.ts'
+import type { IFolder, INode } from '../node/index.ts'
+
+import isSvg from 'is-svg'
+import logger from '../utils/logger.ts'
+
+export interface ISidebarContext {
+	/**
+	 * The active node in the sidebar
+	 */
+	node: INode
+
+	/**
+	 * The current open folder in the files app
+	 */
+	folder: IFolder
+
+	/**
+	 * The currently active view
+	 */
+	view: IView
+}
+
+/**
+ * This component describes the custom web component that should be registered for a sidebar tab.
+ *
+ * @see https://developer.mozilla.org/en-US/docs/Web/API/Web_components
+ * @see https://vuejs.org/guide/extras/web-components#building-custom-elements-with-vue
+ */
+export interface SidebarComponent extends HTMLElement, ISidebarContext {
+	/**
+	 * This method is called by the files app if the sidebar tab state changes.
+	 *
+	 * @param active - The new active state
+	 */
+	setActive(active: boolean): Promise<void>
+}
+
+/**
+ * Implementation of a custom sidebar tab within the files app.
+ */
+export interface ISidebarTab {
+	/**
+	 * Unique id of the sidebar tab.
+	 * This has to conform to the HTML id attribute specification.
+	 */
+	id: string
+
+	/**
+	 * The localized name of the sidebar tab.
+	 */
+	displayName: string
+
+	/**
+	 * The icon, as SVG, of the sidebar tab.
+	 */
+	iconSvgInline: string
+
+	/**
+	 * The order of this tab.
+	 * Use a low number to make this tab ordered in front.
+	 */
+	order: number
+
+	/**
+	 * The tag name of the web component.
+	 * The web component must already be registered under that tag name with `CustomElementRegistry.define()`.
+	 *
+	 * To avoid name clashes the name has to start with your appid (e.g. `your_app`).
+	 * So in addition with the web component naming rules a good name would be `your_app-files-sidebar-tab`.
+	 */
+	tagName: string
+
+	/**
+	 * Callback to check if the sidebar tab should be shown for the selected node.
+	 *
+	 * @param context - The current context of the files app
+	 */
+	enabled: (context: ISidebarContext) => boolean
+}
+
+/**
+ * Register a new sidebar tab for the files app.
+ *
+ * @param tab - The sidebar tab to register
+ * @throws If the provided tab is not a valid sidebar tab and thus cannot be registered.
+ */
+export function registerSidebarTab(tab: ISidebarTab): void {
+	validateSidebarTab(tab)
+
+	window._nc_files_sidebar_tabs ??= new Map<string, ISidebarTab>()
+	if (window._nc_files_sidebar_tabs.has(tab.id)) {
+		logger.warn(`Sidebar tab with id "${tab.id}" already registered. Skipping.`)
+		return
+	}
+	window._nc_files_sidebar_tabs.set(tab.id, tab)
+	logger.debug(`New sidebar tab with id "${tab.id}" registered.`)
+}
+
+/**
+ * Get all currently registered sidebar tabs.
+ */
+export function getSidebarTabs(): ISidebarTab[] {
+	if (window._nc_files_sidebar_tabs) {
+		return [...window._nc_files_sidebar_tabs.values()]
+	}
+	return []
+}
+
+/**
+ * Check if a given sidebar tab objects implements all necessary fields.
+ *
+ * @param tab - The sidebar tab to validate
+ */
+function validateSidebarTab(tab: ISidebarTab): void {
+	if (typeof tab !== 'object') {
+		throw new Error('Sidebar tab is not an object')
+	}
+
+	if (!tab.id || (typeof tab.id !== 'string') || tab.id !== CSS.escape(tab.id)) {
+		throw new Error('Sidebar tabs need to have an id conforming to the HTML id attribute specifications')
+	}
+
+	if (!tab.tagName || typeof tab.tagName !== 'string') {
+		throw new Error('Sidebar tabs need to have the tagName name set')
+	}
+
+	if (!tab.tagName.match(/^[a-z][a-z0-9-_]+$/)) {
+		throw new Error('Sidebar tabs tagName name is invalid')
+	}
+
+	if (!tab.displayName || typeof tab.displayName !== 'string') {
+		throw new Error('Sidebar tabs need to have a name set')
+	}
+
+	if (typeof tab.iconSvgInline !== 'string' || !isSvg(tab.iconSvgInline)) {
+		throw new Error('Sidebar tabs need to have an valid SVG icon')
+	}
+
+	if (typeof tab.order !== 'number') {
+		throw new Error('Sidebar tabs need to have a numeric order set')
+	}
+
+	if (typeof tab.enabled !== 'function') {
+		throw new Error('Sidebar tabs need to have an "enabled" method')
+	}
+
+	// now check the custom element constructor
+	const tagConstructor = window.customElements.get(tab.tagName)
+	if (!tagConstructor) {
+		throw new Error('Sidebar tab element not registered')
+	}
+
+	if (!('setActive' in tagConstructor.prototype)) {
+		// we cannot check properties like `node` or `view` because those are not necessarily defined in the prototype.
+		throw new Error('Sidebar tab elements must have the `setActive` method')
+	}
+}