Files
page-agent/packages/page-controller/src/PageController.ts

429 lines
11 KiB
TypeScript

/**
* Copyright (C) 2025 Alibaba Group Holding Limited
* All rights reserved.
*
* PageController - Manages DOM operations and element interactions.
* Designed to be independent of LLM and can be tested in unit tests.
* All public methods are async for potential remote calling support.
*/
import {
clickElement,
getElementByIndex,
inputTextElement,
scrollHorizontally,
scrollVertically,
selectOptionElement,
} from './actions'
import * as dom from './dom'
import type { FlatDomTree, InteractiveElementDomNode } from './dom/dom_tree/type'
import { getPageInfo } from './dom/getPageInfo'
import { patchReact } from './patches/react'
import { isAnchorElement } from './utils'
/**
* Configuration for PageController
*/
export interface PageControllerConfig extends dom.DomConfig {
/** Enable visual mask overlay during operations (default: false) */
enableMask?: boolean
}
/**
* Structured browser state for LLM consumption
*/
export interface BrowserState {
url: string
title: string
/** Page info + scroll position hint (e.g. "Page info: 1920x1080px...\n[Start of page]") */
header: string
/** Simplified HTML of interactive elements */
content: string
/** Page footer hint (e.g. "... 300 pixels below ..." or "[End of page]") */
footer: string
}
interface ActionResult {
success: boolean
message: string
}
/**
* PageController manages DOM state and element interactions.
* It provides async methods for all DOM operations, keeping state isolated.
*
* @lifecycle
* - beforeUpdate: Emitted before the DOM tree is updated.
* - afterUpdate: Emitted after the DOM tree is updated.
*/
export class PageController extends EventTarget {
private config: PageControllerConfig
/** Corresponds to eval_page in browser-use */
private flatTree: FlatDomTree | null = null
/**
* All highlighted index-mapped interactive elements
* Corresponds to DOMState.selector_map in browser-use
*/
private selectorMap = new Map<number, InteractiveElementDomNode>()
/** Index -> element text description mapping */
private elementTextMap = new Map<number, string>()
/**
* Simplified HTML for LLM consumption.
* Corresponds to clickable_elements_to_string in browser-use
*/
private simplifiedHTML = '<EMPTY>'
/** last time the tree was updated */
private lastTimeUpdate = 0
/** Whether the tree has been indexed at least once */
private isIndexed = false
/** Visual mask overlay for blocking user interaction during automation */
private mask: InstanceType<typeof import('./mask/SimulatorMask').SimulatorMask> | null = null
private maskReady: Promise<void> | null = null
constructor(config: PageControllerConfig = {}) {
super()
this.config = config
patchReact(this)
if (config.enableMask) this.initMask()
}
/**
* Initialize mask asynchronously (dynamic import to avoid CSS loading in Node)
*/
initMask() {
if (this.maskReady !== null) return
this.maskReady = (async () => {
const { SimulatorMask } = await import('./mask/SimulatorMask')
this.mask = new SimulatorMask()
})()
}
// ======= State Queries =======
/**
* Get current page URL
*/
async getCurrentUrl(): Promise<string> {
return window.location.href
}
/**
* Get last tree update timestamp
*/
async getLastUpdateTime(): Promise<number> {
return this.lastTimeUpdate
}
/**
* Get structured browser state for LLM consumption.
* Automatically calls updateTree() to refresh the DOM state.
*/
async getBrowserState(): Promise<BrowserState> {
const url = window.location.href
const title = document.title
const pi = getPageInfo()
const viewportExpansion = dom.resolveViewportExpansion(this.config.viewportExpansion)
await this.updateTree()
const content = this.simplifiedHTML
// Build header: page info + scroll position hint
const titleLine = `Current Page: [${title}](${url})`
const pageInfoLine = `Page info: ${pi.viewport_width}x${pi.viewport_height}px viewport, ${pi.page_width}x${pi.page_height}px total page size, ${pi.pages_above.toFixed(1)} pages above, ${pi.pages_below.toFixed(1)} pages below, ${pi.total_pages.toFixed(1)} total pages, at ${(pi.current_page_position * 100).toFixed(0)}% of page`
const elementsLabel =
viewportExpansion === -1
? 'Interactive elements from top layer of the current page (full page):'
: 'Interactive elements from top layer of the current page inside the viewport:'
const hasContentAbove = pi.pixels_above > 4
const scrollHintAbove =
hasContentAbove && viewportExpansion !== -1
? `... ${pi.pixels_above} pixels above (${pi.pages_above.toFixed(1)} pages) - scroll to see more ...`
: '[Start of page]'
const header = `${titleLine}\n${pageInfoLine}\n\n${elementsLabel}\n\n${scrollHintAbove}`
// Build footer: scroll position hint
const hasContentBelow = pi.pixels_below > 4
const footer =
hasContentBelow && viewportExpansion !== -1
? `... ${pi.pixels_below} pixels below (${pi.pages_below.toFixed(1)} pages) - scroll to see more ...`
: '[End of page]'
return { url, title, header, content, footer }
}
// ======= DOM Tree Operations =======
/**
* Update DOM tree, returns simplified HTML for LLM.
* This is the main method to refresh the page state.
* Automatically bypasses mask during DOM extraction if enabled.
*/
async updateTree(): Promise<string> {
this.dispatchEvent(new Event('beforeUpdate'))
this.lastTimeUpdate = Date.now()
// Temporarily bypass mask to allow DOM extraction
if (this.mask) {
this.mask.wrapper.style.pointerEvents = 'none'
}
dom.cleanUpHighlights()
const blacklist = [
...(this.config.interactiveBlacklist || []),
...document.querySelectorAll('[data-page-agent-not-interactive]').values(),
]
this.flatTree = dom.getFlatTree({
...this.config,
interactiveBlacklist: blacklist,
})
this.simplifiedHTML = dom.flatTreeToString(this.flatTree, this.config.includeAttributes)
this.selectorMap.clear()
this.selectorMap = dom.getSelectorMap(this.flatTree)
this.elementTextMap.clear()
this.elementTextMap = dom.getElementTextMap(this.simplifiedHTML)
// Mark as indexed - now element actions are allowed
this.isIndexed = true
// Restore mask blocking
if (this.mask) {
this.mask.wrapper.style.pointerEvents = 'auto'
}
this.dispatchEvent(new Event('afterUpdate'))
return this.simplifiedHTML
}
/**
* Clean up all element highlights
*/
async cleanUpHighlights(): Promise<void> {
dom.cleanUpHighlights()
}
// ======= Element Actions =======
/**
* Ensure the tree has been indexed before any index-based operation.
* Throws if updateTree() hasn't been called yet.
*/
private assertIndexed(): void {
if (!this.isIndexed) {
throw new Error('DOM tree not indexed yet. Can not perform actions on elements.')
}
}
/**
* Click element by index
*/
async clickElement(index: number): Promise<ActionResult> {
try {
this.assertIndexed()
const element = getElementByIndex(this.selectorMap, index)
const elemText = this.elementTextMap.get(index)
await clickElement(element)
// Handle links that open in new tabs
if (isAnchorElement(element) && element.target === '_blank') {
return {
success: true,
message: `✅ Clicked element (${elemText ?? index}). ⚠️ Link opened in a new tab.`,
}
}
return {
success: true,
message: `✅ Clicked element (${elemText ?? index}).`,
}
} catch (error) {
return {
success: false,
message: `❌ Failed to click element: ${error}`,
}
}
}
/**
* Input text into element by index
*/
async inputText(index: number, text: string): Promise<ActionResult> {
try {
this.assertIndexed()
const element = getElementByIndex(this.selectorMap, index)
const elemText = this.elementTextMap.get(index)
await inputTextElement(element, text)
return {
success: true,
message: `✅ Input text (${text}) into element (${elemText ?? index}).`,
}
} catch (error) {
return {
success: false,
message: `❌ Failed to input text: ${error}`,
}
}
}
/**
* Select dropdown option by index and option text
*/
async selectOption(index: number, optionText: string): Promise<ActionResult> {
try {
this.assertIndexed()
const element = getElementByIndex(this.selectorMap, index)
const elemText = this.elementTextMap.get(index)
await selectOptionElement(element as HTMLSelectElement, optionText)
return {
success: true,
message: `✅ Selected option (${optionText}) in element (${elemText ?? index}).`,
}
} catch (error) {
return {
success: false,
message: `❌ Failed to select option: ${error}`,
}
}
}
/**
* Scroll vertically
*/
async scroll(options: {
down: boolean
numPages: number
pixels?: number
index?: number
}): Promise<ActionResult> {
try {
const { down, numPages, pixels, index } = options
this.assertIndexed()
const scrollAmount = pixels ?? numPages * (down ? 1 : -1) * window.innerHeight
const element = index !== undefined ? getElementByIndex(this.selectorMap, index) : null
const message = await scrollVertically(down, scrollAmount, element)
return {
success: true,
message,
}
} catch (error) {
return {
success: false,
message: `❌ Failed to scroll: ${error}`,
}
}
}
/**
* Scroll horizontally
*/
async scrollHorizontally(options: {
right: boolean
pixels: number
index?: number
}): Promise<ActionResult> {
try {
const { right, pixels, index } = options
this.assertIndexed()
const scrollAmount = pixels * (right ? 1 : -1)
const element = index !== undefined ? getElementByIndex(this.selectorMap, index) : null
const message = await scrollHorizontally(right, scrollAmount, element)
return {
success: true,
message,
}
} catch (error) {
return {
success: false,
message: `❌ Failed to scroll horizontally: ${error}`,
}
}
}
/**
* Execute arbitrary JavaScript on the page
*/
async executeJavascript(script: string): Promise<ActionResult> {
try {
// Wrap script in async function to support await
const asyncFunction = eval(`(async () => { ${script} })`)
const result = await asyncFunction()
return {
success: true,
message: `✅ Executed JavaScript. Result: ${result}`,
}
} catch (error) {
return {
success: false,
message: `❌ Error executing JavaScript: ${error}`,
}
}
}
// ======= Mask Operations =======
/**
* Show the visual mask overlay.
* Only works after mask is setup.
*/
async showMask(): Promise<void> {
await this.maskReady
this.mask?.show()
}
/**
* Hide the visual mask overlay.
* Only works after mask is setup.
*/
async hideMask(): Promise<void> {
await this.maskReady
this.mask?.hide()
}
/**
* Dispose and clean up resources
*/
dispose(): void {
dom.cleanUpHighlights()
this.flatTree = null
this.selectorMap.clear()
this.elementTextMap.clear()
this.simplifiedHTML = '<EMPTY>'
this.isIndexed = false
this.mask?.dispose()
this.mask = null
}
}
export * from './actions'