# Puppeteer API

##### Table of Contents

<!-- toc -->

- [Puppeteer](#puppeteer)
  * [Emulation](#emulation)
  * [class: Browser](#class-browser)
    + [new Browser([options])](#new-browseroptions)
    + [browser.close()](#browserclose)
    + [browser.closePage(page)](#browserclosepagepage)
    + [browser.newPage()](#browsernewpage)
    + [browser.stderr](#browserstderr)
    + [browser.stdout](#browserstdout)
    + [browser.version()](#browserversion)
  * [class: Page](#class-page)
    + [event: 'console'](#event-console)
    + [event: 'dialog'](#event-dialog)
    + [event: 'frameattached'](#event-frameattached)
    + [event: 'framedetached'](#event-framedetached)
    + [event: 'framenavigated'](#event-framenavigated)
    + [event: 'load'](#event-load)
    + [event: 'pageerror'](#event-pageerror)
    + [event: 'request'](#event-request)
    + [event: 'requestfailed'](#event-requestfailed)
    + [event: 'requestfinished'](#event-requestfinished)
    + [event: 'response'](#event-response)
    + [page.$(selector, pageFunction, ...args)](#pageselector-pagefunction-args)
    + [page.$$(selector, pageFunction, ...args)](#pageselector-pagefunction-args)
    + [page.addScriptTag(url)](#pageaddscripttagurl)
    + [page.click(selector[, options])](#pageclickselector-options)
    + [page.close()](#pageclose)
    + [page.evaluate(pageFunction, ...args)](#pageevaluatepagefunction-args)
    + [page.evaluateOnInitialized(pageFunction, ...args)](#pageevaluateoninitializedpagefunction-args)
    + [page.focus(selector)](#pagefocusselector)
    + [page.frames()](#pageframes)
    + [page.goBack(options)](#pagegobackoptions)
    + [page.goForward(options)](#pagegoforwardoptions)
    + [page.hover(selector)](#pagehoverselector)
    + [page.httpHeaders()](#pagehttpheaders)
    + [page.injectFile(filePath)](#pageinjectfilefilepath)
    + [page.keyboard](#pagekeyboard)
    + [page.mainFrame()](#pagemainframe)
    + [page.mouse](#pagemouse)
    + [page.navigate(url, options)](#pagenavigateurl-options)
    + [page.pdf(options)](#pagepdfoptions)
    + [page.plainText()](#pageplaintext)
    + [page.press(key[, options])](#pagepresskey-options)
    + [page.reload(options)](#pagereloadoptions)
    + [page.screenshot([options])](#pagescreenshotoptions)
    + [page.setContent(html)](#pagesetcontenthtml)
    + [page.setHTTPHeaders(headers)](#pagesethttpheadersheaders)
    + [page.setInPageCallback(name, callback)](#pagesetinpagecallbackname-callback)
    + [page.setRequestInterceptor(interceptor)](#pagesetrequestinterceptorinterceptor)
    + [page.setUserAgent(userAgent)](#pagesetuseragentuseragent)
    + [page.setViewport(viewport)](#pagesetviewportviewport)
    + [page.title()](#pagetitle)
    + [page.type(text)](#pagetypetext)
    + [page.uploadFile(selector, ...filePaths)](#pageuploadfileselector-filepaths)
    + [page.url()](#pageurl)
    + [page.userAgent()](#pageuseragent)
    + [page.viewport()](#pageviewport)
    + [page.waitFor(target[, options])](#pagewaitfortarget-options)
    + [page.waitForNavigation(options)](#pagewaitfornavigationoptions)
    + [page.waitForSelector(selector[, options])](#pagewaitforselectorselector-options)
  * [class: Keyboard](#class-keyboard)
    + [keyboard.down(key[, options])](#keyboarddownkey-options)
    + [keyboard.modifiers()](#keyboardmodifiers)
    + [keyboard.sendCharacter(char)](#keyboardsendcharacterchar)
    + [keyboard.up(key)](#keyboardupkey)
  * [class: Mouse](#class-mouse)
    + [mouse.down([options])](#mousedownoptions)
    + [mouse.move(x, y)](#mousemovex-y)
    + [mouse.press([options])](#mousepressoptions)
    + [mouse.up([options])](#mouseupoptions)
  * [class: Dialog](#class-dialog)
    + [dialog.accept([promptText])](#dialogacceptprompttext)
    + [dialog.dismiss()](#dialogdismiss)
    + [dialog.message()](#dialogmessage)
    + [dialog.type](#dialogtype)
  * [class: Frame](#class-frame)
    + [frame.$(selector, pageFunction, ...args)](#frameselector-pagefunction-args)
    + [frame.$$(selector, pageFunction, ...args)](#frameselector-pagefunction-args)
    + [frame.childFrames()](#framechildframes)
    + [frame.click(selector[, options])](#frameclickselector-options)
    + [frame.evaluate(pageFunction, ...args)](#frameevaluatepagefunction-args)
    + [frame.hover(selector)](#framehoverselector)
    + [frame.isDetached()](#frameisdetached)
    + [frame.isMainFrame()](#frameismainframe)
    + [frame.name()](#framename)
    + [frame.parentFrame()](#frameparentframe)
    + [frame.url()](#frameurl)
    + [frame.waitFor(target[, options])](#framewaitfortarget-options)
    + [frame.waitForSelector(selector[, options])](#framewaitforselectorselector-options)
  * [class: Request](#class-request)
    + [request.headers](#requestheaders)
    + [request.method](#requestmethod)
    + [request.response()](#requestresponse)
    + [request.url](#requesturl)
  * [class: Response](#class-response)
    + [response.headers](#responseheaders)
    + [response.ok](#responseok)
    + [response.request()](#responserequest)
    + [response.status](#responsestatus)
    + [response.statusText](#responsestatustext)
    + [response.url](#responseurl)
  * [class: InterceptedRequest](#class-interceptedrequest)
    + [interceptedRequest.abort()](#interceptedrequestabort)
    + [interceptedRequest.continue()](#interceptedrequestcontinue)
    + [interceptedRequest.headers](#interceptedrequestheaders)
    + [interceptedRequest.isHandled()](#interceptedrequestishandled)
    + [interceptedRequest.method](#interceptedrequestmethod)
    + [interceptedRequest.postData](#interceptedrequestpostdata)
    + [interceptedRequest.url](#interceptedrequesturl)
  * [class: Headers](#class-headers)
    + [headers.append(name, value)](#headersappendname-value)
    + [headers.delete(name)](#headersdeletename)
    + [headers.entries()](#headersentries)
    + [headers.get(name)](#headersgetname)
    + [headers.has(name)](#headershasname)
    + [headers.keys()](#headerskeys)
    + [headers.set(name, value)](#headerssetname-value)
    + [headers.values()](#headersvalues)
  * [class: Body](#class-body)
    + [body.arrayBuffer()](#bodyarraybuffer)
    + [body.bodyUsed](#bodybodyused)
    + [body.buffer()](#bodybuffer)
    + [body.json()](#bodyjson)
    + [body.text()](#bodytext)

<!-- tocstop -->

## Puppeteer

Puppeteer is a Node library which provides a high-level API to control Chromium over the DevTools Protocol.

Puppeteer provides a top-level require which has a [Browser](#class-browser) class.
The following is a typical example of using a Browser class to drive automation:
```js
const {Browser} = require('puppeteer');
const browser = new Browser();
browser.newPage().then(async page => {
  await page.navigate('https://google.com');
  // other actions...
  browser.close();
});
```

### Emulation

Puppeteer supports device emulation with two primitives:
- [page.setUserAgent(userAgent)](#pagesetuseragentuseragent)
- [page.setViewport(viewport)](#pagesetviewportviewport)

To aid emulation, puppeteer provides a list of device descriptors which could be obtained via the `require('puppeteer/DeviceDescriptors')` command.
Below is an example of emulating iPhone 6 in puppeteer:
```js
const {Browser} = require('puppeteer');
const devices = require('puppeteer/DeviceDescriptors');
const iPhone = devices['iPhone 6'];
const browser = new Browser();
browser.newPage().then(async page => {
  await Promise.all([
    page.setUserAgent(iPhone.userAgent),
    page.setViewport(iPhone.viewport)
  ]);
  await page.navigate('https://google.com');
  // other actions...
  browser.close();
});
```

List of all available devices is available in the source code: [DeviceDescriptors.js](https://github.com/GoogleChrome/puppeteer/blob/master/DeviceDescriptors.js).

### class: Browser

Browser manages a browser instance, creating it with a predefined
settings, opening and closing pages. Instantiating Browser class does
not necessarily result in launching browser; the instance will be launched when the need will arise.

A typical scenario of using [Browser] is opening a new page and navigating it to a desired URL:
```js
const {Browser} = require('puppeteer');
const browser = new Browser();
browser.newPage().then(async page => {
  await page.navigate('https://example.com');
  browser.close();
})
```

#### new Browser([options])
- `options` <[Object]>  Set of configurable options to set on the browser. Can have the following fields:
	- `headless` <[boolean]> Wether to run chromium in headless mode. Defaults to `true`.
	- `executablePath` <[string]> Path to a chromium executable to run instead of bundled chromium.
	- `args` <[Array]<[string]>> Additional arguments to pass to the chromium instance. List of chromium flags could be found [here](http://peter.sh/experiments/chromium-command-line-switches/).


#### browser.close()

Closes browser with all the pages (if any were opened). The browser object itself is considered to be disposed and could not be used anymore.

#### browser.closePage(page)
- `page` <[Page]> A page to be closed.
- returns: <[Promise]> Promise which resolves when the page is closed.

This is an alias for the `page.close()` method.

#### browser.newPage()
- returns: <[Promise]<[Page]>> Promise which resolves to a new [Page] object.


#### browser.stderr
- <[stream.Readable]>

A Readable Stream that represents the browser process's stderr.
For example, `stderr` could be piped into `process.stderr`:
```js
const {Browser} = require('puppeteer');
const browser = new Browser();
browser.stderr.pipe(process.stderr);
browser.version().then(version => {
  console.log(version);
  browser.close();
});
```

#### browser.stdout
- <[stream.Readable]>

A Readable Stream that represents the browser process's stdout.
For example, `stdout` could be piped into `process.stdout`:
```js
const {Browser} = require('puppeteer');
const browser = new Browser();
browser.stdout.pipe(process.stdout);
browser.version().then(version => {
  console.log(version);
  browser.close();
});
```

#### browser.version()
- returns: <[Promise]<[string]>> String describing browser version. For headless chromium, this is similar to `HeadlessChrome/61.0.3153.0`. For non-headless, this is `Chrome/61.0.3153.0`.

> **NOTE** the format of browser.version() is not fixed and might change with future releases of the library.

### class: Page

Page provides methods to interact with browser page. Page could be thought about as a browser tab, so one [Browser] instance might have multiple [Page] instances.

An example of creating a page, navigating it to a URL and saving screenshot as `screenshot.png`:
```js
const {Browser} = require('puppeteer');
const browser = new Browser();
browser.newPage().then(async page =>
  await page.navigate('https://example.com');
  await page.screenshot({path: 'screenshot.png'});
  browser.close();
});
```

#### event: 'console'
- <[string]>

Emitted when a page calls one of console API methods, e.g. `console.log` or `console.dir`.

If multiple arguments are passed over to the console API call, these arguments are dispatched in an event.

An example of handling `console` event:
```js
page.on('console', (...args) => {
  for (let i =0; i < args.length; ++i)
    console.log(`${i}: ${args[i]}`);
});
page.evaluate(() => console.log(5, 'hello', {foo: 'bar'}));
```

#### event: 'dialog'
- <[Dialog]>

Emitted when a javascript dialog, such as `alert`, `prompt`, `confirm` or `beforeunload`, gets opened on the page. Puppeteer can take action to the dialog via dialog's [accept](#dialogacceptprompttext) or [dismiss](#dialogdismiss) methods.

#### event: 'frameattached'
- <[Frame]>

Emitted when a frame gets attached.

#### event: 'framedetached'
- <[Frame]>

Emitted when a frame gets detached.

#### event: 'framenavigated'
- <[Frame]>

Emitted when a frame committed navigation.

#### event: 'load'

Emitted when a page's `load` event was dispatched.

#### event: 'pageerror'
- <[string]>

Emitted when an unhandled exception happens on the page. The only argument of the event holds the exception message.

#### event: 'request'
- <[Request]>

Emitted when a page issues a request. The [request] object is a read-only object. In order to intercept and mutate requests, see [page.setRequestInterceptor](#pagesetrequestinterceptorinterceptor)

#### event: 'requestfailed'
- <[Request]>

Emitted when a request is failed.

#### event: 'requestfinished'
- <[Request]>

Emitted when a request is successfully finished.

#### event: 'response'
- <[Response]>

Emitted when a [response] is received.

#### page.$(selector, pageFunction, ...args)

- `selector` <[string]> A selector to be matched in the page
- `pageFunction` <[function]\([Element]\)> Function to be evaluated in-page with first element matching `selector`
- `...args` <...[string]> Arguments to pass to `pageFunction`
- returns: <[Promise]<[Object]>> Promise which resolves to function return value.

Example:
```js
const outerhtml = await page.$('#box', e => e.outerHTML);
```

Shortcut for [page.mainFrame().$(selector, pageFunction, ...args)](#pageselector-fun-args).

#### page.$$(selector, pageFunction, ...args)

- `selector` <[string]> A selector to be matched in the page
- `pageFunction` <[function]\([Element]\)> Function to be evaluated in-page for every matching element.
- `...args` <...[string]> Arguments to pass to `pageFunction`
- returns: <[Promise]<[Array]<[Object]>>> Promise which resolves to array of function return values.

Example:
```js
const headings = await page.$$('h1,h2,h3,h4', el => el.textContent);
for (const heading of headings) console.log(heading);
```

Shortcut for [page.mainFrame().$$(selector, pageFunction, ...args)](#pageselector-fun-args).

#### page.addScriptTag(url)
- `url` <[string]> Url of a script to be added
- returns: <[Promise]> Promise which resolves as the script gets added and loads.

Adds a `<script></script>` tag to the page with the desired url. Alternatively, javascript could be injected to the page via `page.injectFile` method.

#### page.click(selector[, options])
- `selector` <[string]> A query selector to search for element to click. If there are multiple elements satisfying the selector, the first will be clicked.
- `options` <[Object]>
  - `button` <[string]> `left`, `right`, or `middle`, defaults to `left`.
  - `clickCount` <[number]> defaults to 1
- returns: <[Promise]> Promise which resolves when the element matching `selector` is successfully clicked. Promise gets rejected if there's no element matching `selector`.

#### page.close()
- returns: <[Promise]> Returns promise which resolves when page gets closed.

#### page.evaluate(pageFunction, ...args)
- `pageFunction` <[function]> Function to be evaluated in browser context
- `...args` <...[string]> Arguments to pass to  `pageFunction`
- returns: <[Promise]<[Object]>> Promise which resolves to function return value

This is a shortcut for [page.mainFrame().evaluate()](#frameevaluatefun-args) method.

#### page.evaluateOnInitialized(pageFunction, ...args)
- `pageFunction` <[function]> Function to be evaluated in browser context
- `...args` <...[string]> Arguments to pass to `pageFunction`
- returns: <[Promise]<[Object]>> Promise which resolves to function

`page.evaluateOnInitialized` adds a function which would run on every page navigation before any page's javascript. This is useful to amend javascript environment, e.g. to seed [Math.random](https://github.com/GoogleChrome/puppeteer/blob/master/examples/unrandomize.js)

#### page.focus(selector)
- `selector` <[string]> A query selector of element to focus. If there are multiple elements satisfying the selector, the first will be focused.
- returns: <[Promise]> Promise which resolves when the element matching `selector` is successfully focused. Promise gets rejected if there's no element matching `selector`.

#### page.frames()
- returns: <[Array]<[Frame]>> An array of all frames attached to the page.

#### page.goBack(options)
- `options` <[Object]> Navigation parameters, same as in [page.navigate](#pagenavigateurl-options).
- returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect. If
can not go back, resolves to null.

Navigate to the previous page in history.

#### page.goForward(options)
- `options` <[Object]> Navigation parameters, same as in [page.navigate](#pagenavigateurl-options).
- returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect. If
can not go back, resolves to null.

Navigate to the next page in history.

#### page.hover(selector)
- `selector` <[string]> A query selector to search for element to hover. If there are multiple elements satisfying the selector, the first will be hovered.
- returns: <[Promise]> Promise which resolves when the element matching `selector` is successfully hovered. Promise gets rejected if there's no element matching `selector`.

#### page.httpHeaders()
- returns: <[Object]> Key-value set of additional http headers which will be sent with every request.

#### page.injectFile(filePath)
- `filePath` <[string]> Path to the javascript file to be injected into page.
- returns: <[Promise]> Promise which resolves when file gets successfully evaluated in page.

#### page.keyboard

- returns: <[Keyboard]>

#### page.mainFrame()
- returns: <[Frame]> returns page's main frame.

Page is guaranteed to have a main frame which persists during navigations.

#### page.mouse

- returns: <[Mouse]>

#### page.navigate(url, options)
- `url` <[string]> URL to navigate page to
- `options` <[Object]> Navigation parameters which might have the following properties:
  - `timeout` <[number]> Maximum navigation time in milliseconds, defaults to 30 seconds.
  - `waitUntil` <[string]> When to consider navigation succeeded, defaults to `load`. Could be either:
    - `load` - consider navigation to be finished when the `load` event is fired.
    - `networkidle` - consider navigation to be finished when the network activity stays "idle" for at least `networkIdleTimeout`ms.
  - `networkIdleInflight` <[number]> Maximum amount of inflight requests which are considered "idle". Takes effect only with `waitUntil: 'networkidle'` parameter.
  - `networkIdleTimeout` <[number]> A timeout to wait before completing navigation. Takes effect only with `waitUntil: 'networkidle'` parameter.
- returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect.

The `page.navigate` will throw an error if:
- there's an SSL error (e.g. in case of self-signed certificates).
- target URL is invalid.
- the `timeout` is exceeded during navigation.

#### page.pdf(options)
- `options` <[Object]> Options object which might have the following properties:
  - `path` <[string]> The file path to save the PDF to.
  - `scale` <[number]> Scale of the webpage rendering. Defaults to `1`.
  - `displayHeaderFooter` <[boolean]> Display header and footer. Defaults to `false`.
  - `printBackground` <[boolean]> Print background graphics. Defaults to `false`.
  - `landscape` <[boolean]> Paper orientation. Defaults to `false`.
  - `pageRanges` <[string]> Paper ranges to print, e.g., '1-5, 8, 11-13'. Defaults to the empty string, which means print all pages.
  - `format` <[string]> Paper format. If set, takes priority over `width` or `height` options. Defaults to 'Letter'.
  - `width` <[string]> Paper width, accepts values labeled with units.
  - `height` <[string]> Paper height, accepts values labeled with units.
  - `margin` <[Object]> Paper margins, defaults to none.
    - `top` <[string]> Top margin, accepts values labeled with units.
    - `right` <[string]> Right margin, accepts values labeled with units.
    - `bottom` <[string]> Bottom margin, accepts values labeled with units.
    - `left` <[string]> Left margin, accepts values labeled with units.
- returns: <[Promise]<[Buffer]>> Promise which resolves with PDF buffer.

The `width`, `height`, and `margin` options accept values labeled with units. Unlabeled values are treated as pixels.

A few examples:
- `page.pdf({width: 100})` - prints with width set to 100 pixels
- `page.pdf({width: '100px'})` - prints with width set to 100 pixels
- `page.pdf({width: '10cm'})` - prints with width set to 10 centimeters.

All possible units are:
- `px` - pixel
- `in` - inch
- `cm` - centimeter
- `mm` - millimeter

The `format` options are:
- `Letter`: 8.5in x 11in
- `Legal`: 8.5in x 14in
- `Tabloid`: 11in x 17in
- `Ledger`: 17in x 11in
- `A0`: 33.1in x 46.8in
- `A1`: 23.4in x 33.1in
- `A2`: 16.5in x 23.4in
- `A3`: 11.7in x 16.5in
- `A4`: 8.27in x 11.7in
- `A5`: 5.83in x 8.27in

#### page.plainText()
- returns:  <[Promise]<[string]>> Returns page's inner text.

#### page.press(key[, options])
- `key` <[string]> Name of key to press, such as `ArrowLeft`. See [KeyboardEvent.key](https://www.w3.org/TR/uievents-key/)
- `options` <[Object]>
  - `text` <[string]> If specified, generates an input event with this text.
- returns: <[Promise]>

Shortcut for [`keyboard.down`](#keyboarddownkey) and [`keyboard.up`](#keyboardupkey).

#### page.reload(options)
- `options` <[Object]> Navigation parameters, same as in [page.navigate](#pagenavigateurl-options).
- returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect.

#### page.screenshot([options])
- `options` <[Object]> Options object which might have the following properties:
    - `path` <[string]> The file path to save the image to. The screenshot type will be inferred from file extension.
    - `type` <[string]> Specify screenshot type, could be either `jpeg` or `png`. Defaults to 'png'.
    - `quality` <[number]> The quality of the image, between 0-100. Not applicable to `png` images.
    - `fullPage` <[boolean]> When true, takes a screenshot of the full scrollable page. Defaults to `false`.
    - `clip` <[Object]> An object which specifies clipping region of the page. Should have the following fields:
        - `x` <[number]> x-coordinate of top-left corner of clip area
        - `y` <[number]> y-coordinate of top-left corner of clip area
        - `width` <[number]> width of clipping area
        - `height` <[number]> height of clipping area
- returns: <[Promise]<[Buffer]>> Promise which resolves to buffer with captured screenshot

#### page.setContent(html)
- `html` <[string]> HTML markup to assign to the page.
- returns: <[Promise]> Promise which resolves when the content is successfully assigned.

#### page.setHTTPHeaders(headers)
- `headers` <[Object]> Key-value set of additional http headers to be sent with every request.
- returns: <[Promise]> Promise which resolves when additional headers are installed

#### page.setInPageCallback(name, callback)
- `name` <[string]> Name of the callback to be assigned on window object
- `callback` <[function]> Callback function which will be called in puppeteer's context.
- returns: <[Promise]> Promise which resolves when callback is successfully initialized

The in-page callback allows page to asynchronously reach back to the Puppeteer.
An example of a page showing amount of CPU's:
```js
const os = require('os');
const {Browser} = require('puppeteer');
const browser = new Browser();

browser.newPage().then(async page =>
  await page.setInPageCallback('getCPUCount', () => os.cpus().length);
  await page.evaluate(async () => {
    alert(await window.getCPUCount());
  });
  browser.close();
});
```

#### page.setRequestInterceptor(interceptor)
- `interceptor` <[function]> Callback function which accepts a single argument of type <[InterceptedRequest]>.
- returns: <[Promise]> Promise which resolves when request interceptor is successfully installed on the page.

After the request interceptor is installed on the page, every request will be reported to the interceptor. The [InterceptedRequest] could be modified and then either continued via the `continue()` method, or aborted via the `abort()` method.

En example of a naive request interceptor which aborts all image requests:
```js
const {Browser} = require('puppeteer');
const browser = new Browser();

browser.newPage().then(async page =>
  await page.setRequestInterceptor(interceptedRequest => {
    if (interceptedRequest.url.endsWith('.png') || interceptedRequest.url.endsWith('.jpg'))
      interceptedRequest.abort();
    else
      interceptedRequest.continue();
  });
  await page.navigate('https://example.com');
  browser.close();
});
```

#### page.setUserAgent(userAgent)
- `userAgent` <[string]> Specific user agent to use in this page
- returns: <[Promise]> Promise which resolves when the user agent is set.

#### page.setViewport(viewport)
- `viewport` <[Object]>  An object with two fields:
	- `width` <[number]> Specify page's width in pixels.
	- `height` <[number]> Specify page's height in pixels.
	- `deviceScaleFactor` <[number]> Specify device scale factor (could be though of as dpr). Defaults to `1`.
	- `isMobile` <[boolean]> Weather the `meta viewport` tag is taken into account. Defaults to `false`.
	- `hasTouch`<[boolean]> Specify if viewport supports touch events. Defaults to `false`
	- `isLandscape` <[boolean]> Specify if viewport is in the landscape mode. Defaults to `false`.
- returns: <[Promise]> Promise which resolves when the dimensions are updated.

Note: in certain cases, setting viewport will reload the page so that the `isMobile` or `hasTouch` options will be able to interfere in project loading.

The page's viewport size defines page's dimensions, observable from page via `window.innerWidth / window.innerHeight`. The viewport size defines a size of page
screenshot (unless a `fullPage` option is given).

In case of multiple pages in one browser, each page can have its own viewport size.

#### page.title()
- returns: <[Promise]<[string]>> Returns page's title.

#### page.type(text)
- `text` <[string]> A text to type into a focused element.
- returns: <[Promise]> Promise which resolves when the text has been successfully typed.

Sends a `keydown`, `keypress`/`input`, and `keyup` event for each character in the text.

To press a special key, use [`page.press`](#pagepresskey-options).

#### page.uploadFile(selector, ...filePaths)
- `selector` <[string]> A query selector to a file input
- `...filePaths` <[string]> Sets the value of the file input these paths
- returns: <[Promise]> Promise which resolves when the value is set.

#### page.url()
- returns: <[string]> Current page url.

This is a shortcut for [page.mainFrame().url()](#frameurl)

#### page.userAgent()
- returns: <[string]> Returns user agent.

#### page.viewport()
- returns: <[Object]>  An object with the save fields as described in [page.setViewport](#pagesetviewportviewport)

#### page.waitFor(target[, options])
- `target` <[string]|[number]> A target to wait for.
- `options` <[Object]> Optional waiting parameters.
- returns: <[Promise]>

Shortcut for [page.mainFrame().waitFor()](#framewaitfortargetoptions).

#### page.waitForNavigation(options)
- `options` <[Object]> Navigation parameters, same as in [page.navigate](#pagenavigateurl-options).
- returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect.

#### page.waitForSelector(selector[, options])
- `selector` <[string]> A query selector to wait for on the page.
- `options` <[Object]> Optional waiting parameters. Same as options for the [frame.waitFor](#framewaitforselector)
- returns: <[Promise]> Promise which resolves when the element matching `selector` appears in the page.

Shortcut for [page.mainFrame().waitForSelector()](#framewaitforselectorselectoroptions).

### class: Keyboard

Keyboard provides an api for managing a virtual keyboard. The high level api is [`page.type`](#pageypetext), which takes raw characters and generates proper keydown, keypress/input, and keyup events on your page.

For finer control, you can use [`keyboard.down`](#keyboarddownkey-options), [`keyboard.up`](#keyboardupkey), and [`keyboard.sendCharacter`](#keyboardsendcharacterchar) to manually fire events as if they were generated from a real keyboard.

An example of holding down `Shift` in order to select and delete some text:
```js
page.type('Hello World!');
page.press('ArrowLeft');

page.keyboard.down('Shift');
for (let i = 0; i < ' World'.length; i++)
  page.press('ArrowLeft');
page.keyboard.up('Shift');

page.press('Backspace');
// Result text will end up saying 'Hello!'
```

#### keyboard.down(key[, options])
- `key` <[string]> Name of key to press, such as `ArrowLeft`. See [KeyboardEvent.key](https://www.w3.org/TR/uievents-key/)
- `options` <[Object]>
  - `text` <[string]> If specified, generates an input event with this text.
- returns: <[Promise]>

Dispatches a `keydown` event.

This will not send input events unless `text` is specified.

If `key` is a modifier key, `Shift`, `Meta`, `Control`, or `Alt`, subsequent key presses will be sent with that modifier active. To release the modifier key, use [`keyboard.up`](#keyboardupkey).

#### keyboard.modifiers()
- returns: <[Object]>
  - `Shift` <[boolean]>
  - `Meta` <[boolean]>
  - `Control` <[boolean]>
  - `Alt` <[boolean]>

Returns which modifier keys are currently active. Use [`keyboard.down`](#keyboarddownkey) to activate a modifier key.

#### keyboard.sendCharacter(char)
- `char` <[string]> Character to send into the page.
- returns: <[Promise]>

Dispatches a `keypress` and `input` event. This does not send a `keydown` or `keyup` event.

```js
page.keyboard.sendCharacter('嗨');
```

#### keyboard.up(key)
- `key` <[string]> Name of key to release, such as `ArrowLeft`. See [KeyboardEvent.key](https://www.w3.org/TR/uievents-key/)
- returns: <[Promise]>

Dispatches a `keyup` event.

### class: Mouse

#### mouse.down([options])
- `options` <[Object]>
  - `button` <[string]> `left`, `right`, or `middle`, defaults to `left`.
  - `clickCount` <[number]> defaults to 1
- returns: <[Promise]>

Dispatches a `mousedown` event.

#### mouse.move(x, y)
- `x` <[number]>
- `y` <[number]>
- returns: <[Promise]>

Dispatches a `mousemove` event.

#### mouse.press([options])
- `options` <[Object]>
  - `button` <[string]> `left`, `right`, or `middle`, defaults to `left`.
  - `clickCount` <[number]> defaults to 1
- returns: <[Promise]>

Shortcut for [`mouse.down`](#mousedownkey) and [`mouse.up`](#mouseupkey).

#### mouse.up([options])
- `options` <[Object]>
  - `button` <[string]> `left`, `right`, or `middle`, defaults to `left`.
  - `clickCount` <[number]> defaults to 1
- returns: <[Promise]>

Dispatches a `mouseup` event.

### class: Dialog

[Dialog] objects are dispatched by page via the ['dialog'](#event-dialog) event.

An example of using `Dialog` class:
```js
const {Browser} = require('puppeteer');
const browser = new Browser({headless: false});
browser.newPage().then(async page => {
  page.on('dialog', dialog => {
    console.log(dialog.message());
    dialog.dismiss();
    browser.close();
  });
  page.evaluate(() => alert('1'));
});
```

> NOTE: Chrome Headless currently has issues with managing javascript dialogs, see [issue 13](https://github.com/GoogleChrome/puppeteer/issues/13)

#### dialog.accept([promptText])
- `promptText` <[string]> A text to enter in prompt. Does not cause any effects if the dialog's `type` is not prompt.
- returns: <[Promise]> Promise which resolves when the dialog has being accepted.

#### dialog.dismiss()
- returns: <[Promise]> Promise which resolves when the dialog has being dismissed.

#### dialog.message()
- returns: <[string]> A message displayed in the dialog.

#### dialog.type
- <[string]>

Dialog's type, could be one of the `alert`, `beforeunload`, `confirm` and `prompt`.

### class: Frame

At every point of time, page exposes its current frame tree via the [page.mainFrame()](#pagemainframe) and [frame.childFrames()](#framechildframes) methods.

[Frame] object's lifecycle is controlled by three events, dispatched on the page object:
- ['frameattached'](#event-frameattached) - fired when the frame gets attached to the page. Frame could be attached to the page only once.
- ['framenavigated'](#event-framenavigated) - fired when the frame commits navigation to a different URL.
- ['framedetached'](#event-framedetached) - fired when the frame gets detached from the page.  Frame could be detached from the page only once.

An example of dumping frame tree:

```js
const {Browser} = new require('.');
const browser = new Browser({headless: true});

browser.newPage().then(async page => {
  await page.navigate('https://www.google.com/chrome/browser/canary.html');
  dumpFrameTree(page.mainFrame(), '');
  browser.close();

  function dumpFrameTree(frame, indent) {
    console.log(indent + frame.url());
    for (let child of frame.childFrames())
      dumpFrameTree(child, indent + '  ');
  }
});
```

#### frame.$(selector, pageFunction, ...args)
- `selector` <[string]> A selector to be matched in the page
- `pageFunction` <[function]\([Element]\)> Function to be evaluated with first element matching `selector`
- `...args` <...[string]> Arguments to pass to `pageFunction`
- returns: <[Promise]<[Object]>> Promise which resolves to function return value.

#### frame.$$(selector, pageFunction, ...args)
- `selector` <[string]> A selector to be matched in the page
- `pageFunction` <[function]\([Element]\)> Function to be evaluted for every element matching `selector`.
- `...args` <...[string]> Arguments to pass to `pageFunction`
- returns: <[Promise]<[Array]<[Object]>>> Promise which resolves to array of function return values.

#### frame.childFrames()
- returns: <[Array]<[Frame]>>

#### frame.click(selector[, options])
- `selector` <[string]> A query selector to search for element to click. If there are multiple elements satisfying the selector, the first will be clicked.
- `options` <[Object]>
  - `button` <[string]> `left`, `right`, or `middle`, defaults to `left`.
  - `clickCount` <[number]> defaults to 1
- returns: <[Promise]> Promise which resolves when the element matching `selector` is successfully clicked. Promise gets rejected if there's no element matching `selector`.

#### frame.evaluate(pageFunction, ...args)
- `pageFunction` <[function]> Function to be evaluated in browser context
- `...args` <...[string]> Arguments to pass to  `pageFunction`
- returns: <[Promise]<[Object]>> Promise which resolves to function return value

If the function, passed to the `page.evaluate`, returns a [Promise], then `page.evaluate` would wait for the promise to resolve and return it's value.

```js
const {Browser} = require('puppeteer');
const browser = new Browser();
browser.newPage().then(async page =>
  const result = await page.evaluate(() => {
    return Promise.resolve().then(() => 8 * 7);
  });
  console.log(result); // prints "56"
  browser.close();
});
```

#### frame.hover(selector)
- `selector` <[string]> A query selector to search for element to hover. If there are multiple elements satisfying the selector, the first will be hovered.
- returns: <[Promise]> Promise which resolves when the element matching `selector` is successfully hovered. Promise gets rejected if there's no element matching `selector`.

#### frame.isDetached()
- returns: <[boolean]>

Returns `true` if the frame has being detached, or `false` otherwise.

#### frame.isMainFrame()
- returns: <[boolean]>

Returns `true` is the frame is page's main frame, or `false` otherwise.

#### frame.name()
- returns: <[string]>

Returns frame's name as specified in the tag.

#### frame.parentFrame()
- returns: <[Frame]> Returns parent frame, if any. Detached frames and main frames return `null`.

#### frame.url()
- returns: <[string]>

Returns frame's url.

#### frame.waitFor(target[, options])
- `target` <[string]|[number]> A target to wait for
- `options` <[Object]> Optional waiting parameters
- returns: <[Promise]>

This method behaves differently wrt the type of the first parameter:
- if `target` is a `string`, than target is treated as a selector to wait for and the method is a shortcut for [frame.waitForSelector](#framewaitforselectorselectoroptions)
- if `target` is a `number`, than target is treated as timeout in milliseconds and the method returns a promise which resolves after the timeout
- otherwise, an exception is thrown

#### frame.waitForSelector(selector[, options])
- `selector` <[string]> CSS selector of awaited element,
- `options` <[Object]> Optional waiting parameters
  - `visible` <[boolean]> wait for element to be present in DOM and to be visible, i.e. to not have `display: none` or `visibility: hidden` CSS properties. Defaults to `false`.
  - `timeout` <[number]> maximum time to wait for in milliseconds. Defaults to `30000` (30 seconds).
- returns: <[Promise]> Promise which resolves when element specified by selector string is added to DOM.

Wait for the `selector` to appear in page. If at the moment of calling
the method the `selector` already exists, the method will return
immediately. If the selector doesn't appear after the `timeout` milliseconds of waiting, the function will throw.

This method works across navigations:
```js
const {Browser} = new require('puppeteer');
const browser = new Browser();

browser.newPage().then(async page => {
  let currentURL;
  page.waitForSelector('img').then(() => console.log('First URL with image: ' + currentURL));
  for (currentURL of ['https://example.com', 'https://google.com', 'https://bbc.com'])
    await page.navigate(currentURL);
  browser.close();
});
```


### class: Request

Whenever the page sends a request, the following events are emitted by puppeteer's page:
- ['request'](#event-request) emitted when the request is issued by the page.
- ['response'](#event-response) emitted when/if the response is received for the request.
- ['requestfinished'](#event-requestfinished) emitted when the response body is downloaded and the request is complete.

If request fails at some point, then instead of 'requestfinished' event (and possibly instead of 'response' event), the  ['requestfailed'](#event-requestfailed) event is emitted.

If request gets a 'redirect' response, the request is successfully finished with the 'requestfinished' event, and a new request is  issued to a redirected url.

[Request] class represents requests which are sent by page. [Request] implements [Body] mixin, which in case of HTTP POST requests allows clients to call `request.json()` or `request.text()` to get different representations of request's body.

#### request.headers
- <[Headers]>

Contains the associated [Headers] object of the request.

#### request.method
- <[string]>

Contains the request's method (GET, POST, etc.)


#### request.response()
- returns: <[Response]> A matching [Response] object, or `null` if the response has not been received yet.

#### request.url
- <[string]>

Contains the URL of the request.

### class: Response

[Response] class represents responses which are received by page. [Response] implements [Body] mixin, which allows clients to call `response.json()` or `response.text()` to get different representations of response body.

#### response.headers
- <[Headers]>

Contains the [Headers] object associated with the response.

#### response.ok
- <[boolean]>

Contains a boolean stating whether the response was successful (status in the range 200-299) or not.

#### response.request()
- returns: <[Request]> A matching [Request] object.


#### response.status
- <[number]>

Contains the status code of the response (e.g., 200 for a success).


#### response.statusText
- <[string]>

Contains the status message corresponding to the status code (e.g., OK for 200).


#### response.url
- <[string]>

Contains the URL of the response.


### class: InterceptedRequest

[InterceptedRequest] represents an intercepted request, which can be mutated and either continued or aborted. [InterceptedRequest] which is not continued or aborted will be in a 'hanging' state.

#### interceptedRequest.abort()

Aborts request.

#### interceptedRequest.continue()

Continues request.

#### interceptedRequest.headers
- <[Headers]>

Contains the [Headers] object associated with the request.

Headers could be mutated with the `headers.append`, `headers.set` and other
methods. Must not be changed in response to an authChallenge.

#### interceptedRequest.isHandled()
- returns: <[boolean]> returns `true` if either `abort` or `continue` was called on the object. Otherwise, returns `false`.

#### interceptedRequest.method
- <[string]>

Contains the request's method (GET, POST, etc.)

If set this allows the request method to be overridden. Must not be changed in response to an authChallenge.

#### interceptedRequest.postData
- <[string]>

Contains `POST` data for `POST` requests.

`request.postData` is mutable and could be written to. Must not be changed in response to an authChallenge.

#### interceptedRequest.url
- <[string]>

If changed, the request url will be modified in a way that's not observable by page. Must not be changed in response to an authChallenge.

### class: Headers
#### headers.append(name, value)
- `name` <[string]> Case-insensetive header name.
- `value` <[string]> Header value

If there's already a header with name `name`, the header gets overwritten.

#### headers.delete(name)
- `name` <[string]> Case-insensetive name of the header to be deleted. If there's no header with such name, the method does nothing.

#### headers.entries()
- returns: <[iterator]> An iterator allowing to go through all key/value pairs contained in this object. Both the key and value of each pairs are [string] objects.


#### headers.get(name)
- `name` <[string]> Case-insensetive name of the header.
- returns: <[string]> Header value of `null`, if there's no such header.

#### headers.has(name)
- `name` <[string]> Case-insensetive name of the header.
- returns: <[boolean]> Returns `true` if the header with such name exists, or `false` otherwise.

#### headers.keys()
- returns: <[iterator]> an iterator allowing to go through all keys contained in this object. The keys are [string] objects.


#### headers.set(name, value)
- `name` <[string]> Case-insensetive header name.
- `value` <[string]> Header value

If there's already a header with name `name`, the header gets overwritten.

#### headers.values()
- returns: <[iterator]<[string]>> Returns an iterator allowing to go through all values contained in this object. The values are [string] objects.

### class: Body
#### body.arrayBuffer()
- returns: <Promise<[ArrayBuffer]>>


#### body.bodyUsed
- returns: <[boolean]>

#### body.buffer()
- returns: <Promise<[Buffer]>>

#### body.json()
- returns: <Promise<[Object]>>

#### body.text()
- returns: <Promise<[text]>>

[Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array "Array"
[ArrayBuffer]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer "ArrayBuffer"
[boolean]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type "Boolean"
[Buffer]: https://nodejs.org/api/buffer.html#buffer_class_buffer "Buffer"
[function]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function "Function"
[number]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type "Number"
[Object]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object "Object"
[Page]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-page "Page"
[Headers]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-headers "Headers"
[InterceptedRequest]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-interceptedrequest "Page"
[Promise]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise "Promise"
[string]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type "String"
[stream.Readable]: https://nodejs.org/api/stream.html#stream_class_stream_readable "stream.Readable"
[Frame]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-frame "Frame"
[iterator]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols "Iterator"
[Response]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-response  "Response"
[Request]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-request  "Request"
[Browser]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-browser  "Browser"
[Body]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-body  "Body"
[Element]: https://developer.mozilla.org/en-US/docs/Web/API/element "Element"
[Keyboard]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-keyboard "Keyboard"
[Dialog]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-dialog  "Dialog"
[Mouse]: https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#class-mouse "Mouse"