rrweb/guide.md

Guide

中文指南

You may also want to read the recipes to find some use real-world use case, or read the design docs to know more technical details of rrweb.

Installation

Direct <script> include

You are recommended to install rrweb via jsdelivr's CDN service:

<link
  rel="stylesheet"
  href="https://cdn.jsdelivr.net/npm/rrweb@latest/dist/style.css"
/>
<script src="https://cdn.jsdelivr.net/npm/rrweb@latest/dist/rrweb.umd.min.cjs"></script>

Also, you can link to a specific version number that you can update manually:

<script src="https://cdn.jsdelivr.net/npm/rrweb@2.0.0-alpha.14/dist/rrweb.umd.min.cjs"></script>

Only include the recorder code

rrweb's code includes both the record and the replay parts. Most of the time you only need to include the record part into your targeted web Apps. This also can be done by using the @rrweb/record package and the CDN service:

<script src="https://cdn.jsdelivr.net/npm/@rrweb/record@latest/dist/record.umd.min.cjs"></script>

Other packages

Besides the rrweb and @rrweb/record packages, rrweb also provides other packages for different usage.

• rrweb: The core package of rrweb, including record and replay functions.
• rrweb-player: A GUI for rrweb, providing a timeline and buttons for things like pause, fast-forward, and speedup.
• rrweb-snapshot: Handles snapshot and rebuilding features, converting the DOM and its state into a serializable data structure.
• rrdom: A virtual dom package rrweb.
• rrdom-nodejs: The Node.js version of rrdom for server-side DOM operations.
• @rrweb/all: A package that includes rrweb and @rrweb/packer for easy install.
• @rrweb/record: A package for recording rrweb sessions.
• @rrweb/replay: A package for replaying rrweb sessions.
• @rrweb/packer: A package for packing and unpacking rrweb data.
• @rrweb/types: Contains types shared across rrweb packages.
• web-extension: A web extension for rrweb.
• rrvideo: A package for handling video operations in rrweb.
• @rrweb/rrweb-plugin-console-record: A plugin for recording console logs.
• @rrweb/rrweb-plugin-console-replay: A plugin for replaying console logs.
• @rrweb/rrweb-plugin-sequential-id-record: A plugin for recording sequential IDs.
• @rrweb/rrweb-plugin-sequential-id-replay: A plugin for replaying sequential IDs.
• @rrweb/rrweb-plugin-canvas-webrtc-record: A plugin for stream <canvas> via WebRTC.
• @rrweb/rrweb-plugin-canvas-webrtc-replay: A plugin for playing streamed <canvas> via WebRTC.

NPM

npm install --save rrweb

rrweb provides both commonJS and ES modules bundles, which are easy to use with the popular bundlers.

Compatibility Note

rrweb does not support IE11 and below because it uses the MutationObserver API which was supported by these browsers.

Getting Started

Record

The following sample code will use the variable rrweb which is the default exporter of this library.

rrweb.record({
  emit(event) {
    // store the event in any way you like
  },
});

During recording, the recorder will emit when there is some event incurred, all you need to do is to store the emitted events in any way you like.

The record method returns a function which can be called to stop events from firing:

let stopFn = rrweb.record({
  emit(event) {
    if (events.length > 100) {
      // stop after 100 events
      stopFn();
    }
  },
});

A more real-world usage may look like this:

let events = [];

rrweb.record({
  emit(event) {
    // push event into the events array
    events.push(event);
  },
});

// this function will send events to the backend and reset the events array
function save() {
  const body = JSON.stringify({ events });
  events = [];
  fetch('http://YOUR_BACKEND_API', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body,
  });
}

// save events every 10 seconds
setInterval(save, 10 * 1000);

Options

The parameter of rrweb.record accepts the following options.

key	default	description
emit	required	the callback function to get emitted events
checkoutEveryNth	-	take a full snapshot after every N events refer to the checkout chapter
checkoutEveryNms	-	take a full snapshot after every N ms refer to the checkout chapter
blockClass	'rr-block'	Use a string or RegExp to configure which elements should be blocked, refer to the privacy chapter
blockSelector	null	Use a string to configure which selector should be blocked, refer to the privacy chapter
ignoreClass	'rr-ignore'	Use a string or RegExp to configure which elements should be ignored, refer to the privacy chapter
ignoreSelector	null	Use a string to configure which selector should be ignored, refer to the privacy chapter
ignoreCSSAttributes	null	array of CSS attributes that should be ignored
maskTextClass	'rr-mask'	Use a string or RegExp to configure which elements should be masked, refer to the privacy chapter
maskTextSelector	null	Use a string to configure which selector should be masked, refer to the privacy chapter
maskAllInputs	false	mask all input content as *
maskInputOptions	{ password: true }	mask some kinds of input * refer to the list
maskInputFn	-	customize mask input content recording logic
maskTextFn	-	customize mask text content recording logic
slimDOMOptions	{}	remove unnecessary parts of the DOM refer to the list
dataURLOptions	{}	Canvas image format and quality ,This parameter will be passed to the OffscreenCanvas.convertToBlob(),Using this parameter effectively reduces the size of the recorded data
inlineStylesheet	true	whether to inline the stylesheet in the events
hooks	{}	hooks for events refer to the list
packFn	-	refer to the storage optimization recipe
sampling	-	refer to the storage optimization recipe
recordCanvas	false	Whether to record the canvas element. Available options: false, true
recordCrossOriginIframes	false	Whether to record cross origin iframes. rrweb has to be injected in each child iframe for this to work. Available options: false, true
recordAfter	'load'	If the document is not ready, then the recorder will start recording after the specified event is fired. Available options: DOMContentLoaded, load
inlineImages	false	whether to record the image content
collectFonts	false	whether to collect fonts in the website
userTriggeredOnInput	false	whether to add userTriggered on input events that indicates if this event was triggered directly by the user or not. What is userTriggered?
plugins	[]	load plugins to provide extended record functions. What is plugins?
errorHandler	-	A callback that is called if something inside of rrweb throws an error. The callback receives the error as argument.

Privacy

You may find some contents on the webpage which are not willing to be recorded, then you can use the following approaches:

• An element with the class name .rr-block will not be recorded. Instead, it will replay as a placeholder with the same dimension.
• An element with the class name .rr-ignore will not record its input events.
• All text of elements with the class name .rr-mask and their children will be masked.
• input[type="password"] will be masked by default.
• Mask options to mask the content in input elements.

Checkout

By default, all the emitted events are required to replay a session and if you do not want to store all the events, you can use the checkout config.

Most of the time you do not need to configure this. But if you want to do something like capturing just the last N events from when an error has occurred, here is an example:

// We use a two-dimensional array to store multiple events array
const eventsMatrix = [[]];

rrweb.record({
  emit(event, isCheckout) {
    // isCheckout is a flag to tell you the events has been checkout
    if (isCheckout) {
      eventsMatrix.push([]);
    }
    const lastEvents = eventsMatrix[eventsMatrix.length - 1];
    lastEvents.push(event);
  },
  checkoutEveryNth: 200, // checkout every 200 events
});

// send last two events array to the backend
window.onerror = function () {
  const len = eventsMatrix.length;
  const events = eventsMatrix[len - 2].concat(eventsMatrix[len - 1]);
  const body = JSON.stringify({ events });
  fetch('http://YOUR_BACKEND_API', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body,
  });
};

Due to the incremental-snapshot-chain mechanism rrweb used, we can not capture the last N events accurately. With the sample code above, you will finally get the last 200 to 400 events been sent to your backend.

Similarly, you can also configure checkoutEveryNms to capture the last N minutes events:

// We use a two-dimensional array to store multiple events array
const eventsMatrix = [[]];

rrweb.record({
  emit(event, isCheckout) {
    // isCheckout is a flag to tell you the events has been checkout
    if (isCheckout) {
      eventsMatrix.push([]);
    }
    const lastEvents = eventsMatrix[eventsMatrix.length - 1];
    lastEvents.push(event);
  },
  checkoutEveryNms: 5 * 60 * 1000, // checkout every 5 minutes
});

// send last two events array to the backend
window.onerror = function () {
  const len = eventsMatrix.length;
  const events = eventsMatrix[len - 2].concat(eventsMatrix[len - 1]);
  const body = JSON.stringify({ events });
  fetch('http://YOUR_BACKEND_API', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body,
  });
};

With the sample code above, you will finally get the last 5 to 10 minutes of events been sent to your backend.

Replay

You need to include the style sheet before replay:

<link
  rel="stylesheet"
  href="https://cdn.jsdelivr.net/npm/rrweb@latest/dist/style.css"
/>

And then initialize the replayer with the following code:

const events = YOUR_EVENTS;

const replayer = new rrweb.Replayer(events);
replayer.play();

Control the replayer by API

const replayer = new rrweb.Replayer(events);

// play
replayer.play();

// play from the third seconds
replayer.play(3000);

// pause
replayer.pause();

// pause at the fifth seconds
replayer.pause(5000);

// destroy the replayer (hint: this operation is irreversible)
replayer.destroy();

Options

The replayer accepts options as its constructor's second parameter, and it has the following options:

key	default	description
speed	1	replay speed ratio
root	document.body	the root element of replayer
loadTimeout	0	timeout of loading remote style sheet
skipInactive	false	whether to skip inactive time
inactivePeriodThreshold	10000	the threshold in milliseconds for what should be considered an inactive period
showWarning	true	whether to print warning messages during replay
showDebug	false	whether to print debug messages during replay
blockClass	'rr-block'	element with the class name will display as a blocked area
liveMode	false	whether to enable live mode
insertStyleRules	[]	accepts multiple CSS rule string, which will be injected into the replay iframe
triggerFocus	true	whether to trigger focus during replay
UNSAFE_replayCanvas	false	whether to replay the canvas element. Enable this will remove the sandbox, which is unsafe.
pauseAnimation	true	whether to pause CSS animation when the replayer is paused
mouseTail	true	whether to show mouse tail during replay. Set to false to disable mouse tail. A complete config can be found in this type
unpackFn	-	refer to the storage optimization recipe
logConfig	-	configuration of console output playback, refer to the console recipe
plugins	[]	load plugins to provide extended replay functions. What is plugins?
useVirtualDom	true	whether to use Virtual Dom optimization in the process of skipping to a new point of time
logger	console	The logger object used by the replayer to print warnings or errors

Use rrweb-player

Since rrweb's replayer (@rrweb/replay) only provides a basic UI, you can choose rrweb-player which is based on rrweb's public APIs but has a feature-rich replayer UI.

Installation

rrweb-player can also be included with <script>：

<link
  rel="stylesheet"
  href="https://cdn.jsdelivr.net/npm/rrweb-player@latest/dist/style.css"
/>
<script src="https://cdn.jsdelivr.net/npm/rrweb-player@latest/dist/index.js"></script>

Or installed by using NPM：

npm install --save rrweb-player

import rrwebPlayer from 'rrweb-player';
import 'rrweb-player/dist/style.css';

Usage

new rrwebPlayer({
  target: document.body, // customizable root element
  props: {
    events,
  },
});

Options

key	default	description
events	[]	the events for replaying
width	1024	the width of the replayer
height	576	the height of the replayer
maxScale	1	the maximum scale of the replayer (1 = 100%), set to 0 for unlimited
autoPlay	true	whether to autoplay
speedOption	[1, 2, 4, 8]	speed options in UI
showController	true	whether to show the controller UI
tags	{}	customize the custom events style with a key-value map
...	-	all the rrweb Replayer options will be bypassed

Events

Developers may want to extend the rrweb's replayer or respond to its events. Such as giving notification when the replayer starts to skip inactive time. So rrweb expose a public API on which allow developers to listen to the events and customize the reactions, and it has the following events:

const replayer = new rrweb.Replayer(events);
replayer.on(EVENT_NAME, (payload) => {
  ...
})

The event list:

Event	Description	Value
start	started to replay	-
pause	paused the replay	-
finish	finished the replay	-
resize	the viewport has changed	{ width, height }
fullsnapshot-rebuilded	rebuilded a full snapshot	event
load-stylesheet-start	started to load remote stylesheets	-
load-stylesheet-end	loaded remote stylesheets	-
skip-start	started to skip inactive time	{ speed }
skip-end	skipped inactive time	{ speed }
mouse-interaction	mouse interaction has been replayed	{ type, target }
event-cast	event has been replayed	event
custom-event	custom event has been replayed	event
destroy	destroyed the replayer	-

The rrweb-replayer also re-expose the event listener via a component.addEventListener API.

And there are three rrweb-replayer event will be emitted in the same way:

Event	Description	Value
ui-update-current-time	current time has changed	{ payload }
ui-update-player-state	current player state has changed	{ payload }
ui-update-progress	current progress has changed	{ payload }

REPL tool

You can also play with rrweb by using the REPL testing tool which does not need installation.

Run yarn repl to launch a browser and ask for a URL you want to test on the CLI:

Enter the url you want to record, e.g https://react-redux.realworld.io:

Waiting for the browser to open the specified page and print the following messages on the CLI:

Enter the url you want to record, e.g https://react-redux.realworld.io: https://github.com
Going to open https://github.com...
Ready to record. You can do any interaction on the page.
Once you want to finish the recording, enter 'y' to start replay:

At this point, you can interact on the web page. After the desired operations have been recorded, enter 'y' on the CLI, and the test tool will replay the operations to verify whether the recording was successful.

The following messages will be printed on the CLI during replay:

Enter 'y' to persistently store these recorded events:

At this point, you can enter 'y' again on the CLI. The test tool will save the recorded session into a static HTML file and prompt for the location:

Saved at PATH_TO_YOUR_REPO/temp/replay_2018_11_23T07_53_30.html

This file uses the latest rrweb bundle code, so we can run npm run bundle:browser after patching the code, then refresh the static file to see and debug the impact of the latest code on replay.