Project

ferrum

0.47
The project is in a healthy, maintained state
Ferrum allows you to control headless Chrome browser
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 Project Readme

Ferrum - high-level API to control Chrome in Ruby

Ferrum logo

As simple as Puppeteer, though even simpler.

It is Ruby clean and high-level API to Chrome. Runs headless by default, but you can configure it to run in a headful mode. All you need is Ruby and Chrome or Chromium. Ferrum connects to the browser by CDP protocol and there's no Selenium/WebDriver/ChromeDriver dependency. The emphasis was made on a raw CDP protocol because Chrome allows you to do so many things that are barely supported by WebDriver because it should have consistent design with other browsers.

  • Cuprite is a pure Ruby driver for Capybara based on Ferrum. If you are going to crawl sites you better use Ferrum or Vessel because you crawl, not test.

  • Vessel high-level web crawling framework based on Ferrum. It looks like Scrapy except that it uses a real browser in order to grab data.

Web design by Evrone, what else we build with Ruby on Rails, what else we do at Evrone.

Index

Install

There's no official Chrome or Chromium package for Linux don't install it this way because it's either outdated or unofficial, both are bad. Download it from official source. Chrome binary should be in the PATH or BROWSER_PATH or you can pass it as an option to browser instance see :browser_path in Customization.

Add this to your Gemfile and run bundle install.

gem "ferrum"

Examples

Navigate to a website and save a screenshot:

browser = Ferrum::Browser.new
browser.go_to("https://google.com")
browser.screenshot(path: "google.png")
browser.quit

Interact with a page:

browser = Ferrum::Browser.new
browser.go_to("https://google.com")
input = browser.at_xpath("//input[@name='q']")
input.focus.type("Ruby headless driver for Chrome", :Enter)
browser.at_css("a > h3").text # => "rubycdp/ferrum: Ruby Chrome/Chromium driver - GitHub"
browser.quit

Evaluate some JavaScript and get full width/height:

browser = Ferrum::Browser.new
browser.go_to("https://www.google.com/search?q=Ruby+headless+driver+for+Capybara")
width, height = browser.evaluate <<~JS
  [document.documentElement.offsetWidth,
   document.documentElement.offsetHeight]
JS
# => [1024, 1931]
browser.quit

Do any mouse movements you like:

# Trace a 100x100 square
browser = Ferrum::Browser.new
browser.go_to("https://google.com")
browser.mouse
  .move(x: 0, y: 0)
  .down
  .move(x: 0, y: 100)
  .move(x: 100, y: 100)
  .move(x: 100, y: 0)
  .move(x: 0, y: 0)
  .up

browser.quit

Docker

In docker as root you must pass the no-sandbox browser option:

Ferrum::Browser.new(browser_options: { 'no-sandbox': nil })

Customization

You can customize options with the following code in your test setup:

Ferrum::Browser.new(options)
  • options Hash
    • :headless (Boolean) - Set browser as headless or not, true by default.
    • :xvfb (Boolean) - Run browser in a virtual framebuffer, false by default.
    • :window_size (Array) - The dimensions of the browser window in which to test, expressed as a 2-element array, e.g. [1024, 768]. Default: [1024, 768]
    • :extensions (Array[String | Hash]) - An array of paths to files or JS source code to be preloaded into the browser e.g.: ["/path/to/script.js", { source: "window.secret = 'top'" }]
    • :logger (Object responding to puts) - When present, debug output is written to this object.
    • :slowmo (Integer | Float) - Set a delay in seconds to wait before sending command. Usefull companion of headless option, so that you have time to see changes.
    • :timeout (Numeric) - The number of seconds we'll wait for a response when communicating with browser. Default is 5.
    • :js_errors (Boolean) - When true, JavaScript errors get re-raised in Ruby.
    • :pending_connection_errors (Boolean) - When main frame is still waiting for slow responses while timeout is reached PendingConnectionsError is raised. It's better to figure out why you have slow responses and fix or block them rather than turn this setting off. Default is true.
    • :browser_name (Symbol) - :chrome by default, only experimental support for :firefox for now.
    • :browser_path (String) - Path to Chrome binary, you can also set ENV variable as BROWSER_PATH=some/path/chrome bundle exec rspec.
    • :browser_options (Hash) - Additional command line options, see them all e.g. { "ignore-certificate-errors" => nil }
    • :ignore_default_browser_options (Boolean) - Ferrum has a number of default options it passes to the browser, if you set this to true then only options you put in :browser_options will be passed to the browser, except required ones of course.
    • :port (Integer) - Remote debugging port for headless Chrome
    • :host (String) - Remote debugging address for headless Chrome
    • :url (String) - URL for a running instance of Chrome. If this is set, a browser process will not be spawned.
    • :process_timeout (Integer) - How long to wait for the Chrome process to respond on startup
    • :ws_max_receive_size (Integer) - How big messages to accept from Chrome over the web socket, in bytes. Defaults to 64MB. Incoming messages larger than this will cause a Ferrum::DeadBrowserError.

Navigation

go_to(url) : String

Navigate page to.

  • url String The url should include scheme unless you set base_url when configuring driver.
browser.go_to("https://github.com/")

back

Navigate to the previous page in history.

browser.go_to("https://github.com/")
browser.at_xpath("//a").click
browser.back

forward

Navigate to the next page in history.

browser.go_to("https://github.com/")
browser.at_xpath("//a").click
browser.back
browser.forward

refresh

Reload current page.

browser.go_to("https://github.com/")
browser.refresh

stop

Stop all navigations and loading pending resources on the page

browser.go_to("https://github.com/")
browser.stop

position = **options

Set the position for the browser window

  • options Hash
    • :left Integer
    • :top Integer
browser.position = { left: 10, top: 20 }

position : Array<Integer>

Get the position for the browser window

browser.position # => [10, 20]

Finders

at_css(selector, **options) : Node | nil

Find node by selector. Runs document.querySelector within the document or provided node.

  • selector String
  • options Hash
    • :within Node | nil
browser.go_to("https://github.com/")
browser.at_css("a[aria-label='Issues you created']") # => Node

css(selector, **options) : Array<Node> | []

Find nodes by selector. The method runs document.querySelectorAll within the document or provided node.

  • selector String
  • options Hash
    • :within Node | nil
browser.go_to("https://github.com/")
browser.css("a[aria-label='Issues you created']") # => [Node]

at_xpath(selector, **options) : Node | nil

Find node by xpath.

  • selector String
  • options Hash
    • :within Node | nil
browser.go_to("https://github.com/")
browser.at_xpath("//a[@aria-label='Issues you created']") # => Node

xpath(selector, **options) : Array<Node> | []

Find nodes by xpath.

  • selector String
  • options Hash
    • :within Node | nil
browser.go_to("https://github.com/")
browser.xpath("//a[@aria-label='Issues you created']") # => [Node]

current_url : String

Returns current top window location href.

browser.go_to("https://google.com/")
browser.current_url # => "https://www.google.com/"

current_title : String

Returns current top window title

browser.go_to("https://google.com/")
browser.current_title # => "Google"

body : String

Returns current page's html.

browser.go_to("https://google.com/")
browser.body # => '<html itemscope="" itemtype="http://schema.org/WebPage" lang="ru"><head>...

Screenshots

screenshot(**options) : String | Integer

Saves screenshot on a disk or returns it as base64.

  • options Hash
    • :path String to save a screenshot on the disk. :encoding will be set to :binary automatically
    • :encoding Symbol :base64 | :binary you can set it to return image as Base64
    • :format String "jpeg" | "png"
    • :quality Integer 0-100 works for jpeg only
    • :full Boolean whether you need full page screenshot or a viewport
    • :selector String css selector for given element
    • :scale Float zoom in/out
    • :background_color Ferrum::RGBA.new(0, 0, 0, 0.0) to have specific background color
browser.go_to("https://google.com/")
# Save on the disk in PNG
browser.screenshot(path: "google.png") # => 134660
# Save on the disk in JPG
browser.screenshot(path: "google.jpg") # => 30902
# Save to Base64 the whole page not only viewport and reduce quality
browser.screenshot(full: true, quality: 60) # "iVBORw0KGgoAAAANSUhEUgAABAAAAAMACAYAAAC6uhUNAAAAAXNSR0IArs4c6Q...
# Save with specific background color
browser.screenshot(background_color: Ferrum::RGBA.new(0, 0, 0, 0.0))

pdf(**options) : String | Boolean

Saves PDF on a disk or returns it as base64.

  • options Hash
    • :path String to save a pdf on the disk. :encoding will be set to :binary automatically

    • :encoding Symbol :base64 | :binary you can set it to return pdf as Base64

    • :landscape Boolean paper orientation. Defaults to false.

    • :scale Float zoom in/out

    • :format symbol standard paper sizes :letter, :legal, :tabloid, :ledger, :A0, :A1, :A2, :A3, :A4, :A5, :A6

    • :paper_width Float set paper width

    • :paper_height Float set paper height

    • See other native options you can pass

browser.go_to("https://google.com/")
# Save to disk as a PDF
browser.pdf(path: "google.pdf", paper_width: 1.0, paper_height: 1.0) # => true

mhtml(**options) : String | Integer

Saves MHTML on a disk or returns it as a string.

  • options Hash
    • :path String to save a file on the disk.
browser.go_to("https://google.com/")
browser.mhtml(path: "google.mhtml") # => 87742

Network

browser.network

traffic Array<Network::Exchange>

Returns all information about network traffic as Network::Exchange instance which in general is a wrapper around request, response and error.

browser.go_to("https://github.com/")
browser.network.traffic # => [#<Ferrum::Network::Exchange, ...]

request : Network::Request

Page request of the main frame.

browser.go_to("https://github.com/")
browser.network.request # => #<Ferrum::Network::Request...

response : Network::Response

Page response of the main frame.

browser.go_to("https://github.com/")
browser.network.response # => #<Ferrum::Network::Response...

status : Integer

Contains the status code of the main page response (e.g., 200 for a success). This is just a shortcut for response.status.

browser.go_to("https://github.com/")
browser.network.status # => 200

wait_for_idle(**options)

Waits for network idle or raises Ferrum::TimeoutError error

  • options Hash
    • :connections Integer how many connections are allowed for network to be idling, 0 by default
    • :duration Float sleep for given amount of time and check again, 0.05 by default
    • :timeout Float during what time we try to check idle, browser.timeout by default
browser.go_to("https://example.com/")
browser.at_xpath("//a[text() = 'No UI changes button']").click
browser.network.wait_for_idle

clear(type)

Clear browser's cache or collected traffic.

  • type Symbol it is either :traffic or :cache
traffic = browser.network.traffic # => []
browser.go_to("https://github.com/")
traffic.size # => 51
browser.network.clear(:traffic)
traffic.size # => 0

intercept(**options)

Set request interception for given options. This method is only sets request interception, you should use on callback to catch requests and abort or continue them.

  • options Hash
    • :pattern String * by default
    • :resource_type Symbol one of the resource types
browser = Ferrum::Browser.new
browser.network.intercept
browser.on(:request) do |request|
  if request.match?(/bla-bla/)
    request.abort
  elsif request.match?(/lorem/)
    request.respond(body: "Lorem ipsum")
  else
    request.continue
  end
end
browser.go_to("https://google.com")

authorize(**options, &block)

If site or proxy uses authorization you can provide credentials using this method.

  • options Hash
    • :type Symbol :server | :proxy site or proxy authorization
    • :user String
    • :password String
  • &block accepts authenticated request, which you must subsequently allow or deny, if you don't care about unwanted requests just call request.continue.
browser.network.authorize(user: "login", password: "pass") { |req| req.continue }
browser.go_to("http://example.com/authenticated")
puts browser.network.status # => 200
puts browser.body # => Welcome, authenticated client

Since Chrome implements authorize using request interception you must continue or abort authorized requests. If you already have code that uses interception you can use authorize without block, but if not you are obliged to pass block, so this is version doesn't pass block and can work just fine:

browser = Ferrum::Browser.new
browser.network.intercept
browser.on(:request) do |request|
  if request.resource_type == "Image"
    request.abort
  else
    request.continue
  end
end

browser.network.authorize(user: "login", password: "pass", type: :proxy)

browser.go_to("https://google.com")

You used to call authorize method without block, but since it's implemented using request interception there could be a collision with another part of your code that also uses request interception, so that authorize allows the request while your code denies but it's too late. The block is mandatory now.

Mouse

browser.mouse

scroll_to(x, y)

Scroll page to a given x, y

  • x Integer the pixel along the horizontal axis of the document that you want displayed in the upper left
  • y Integer the pixel along the vertical axis of the document that you want displayed in the upper left
browser.go_to("https://www.google.com/search?q=Ruby+headless+driver+for+Capybara")
browser.mouse.scroll_to(0, 400)

click(**options) : Mouse

Click given coordinates, fires mouse move, down and up events.

  • options Hash
    • :x Integer
    • :y Integer
    • :delay Float defaults to 0. Delay between mouse down and mouse up events
    • :button Symbol :left | :right, defaults to :left
    • :count Integer defaults to 1
    • :modifiers Integer bitfield for key modifiers. Seekeyboard.modifiers

down(**options) : Mouse

Mouse down for given coordinates.

  • options Hash
    • :button Symbol :left | :right, defaults to :left
    • :count Integer defaults to 1
    • :modifiers Integer bitfield for key modifiers. Seekeyboard.modifiers

up(**options) : Mouse

Mouse up for given coordinates.

  • options Hash
    • :button Symbol :left | :right, defaults to :left
    • :count Integer defaults to 1
    • :modifiers Integer bitfield for key modifiers. Seekeyboard.modifiers

move(x:, y:, steps: 1) : Mouse

Mouse move to given x and y.

  • options Hash
    • :x Integer
    • :y Integer
    • :steps Integer defaults to 1. Sends intermediate mousemove events.

Keyboard

browser.keyboard

down(key) : Keyboard

Dispatches a keydown event.

  • key String | Symbol Name of key such as "a", :enter, :backspace

up(key) : Keyboard

Dispatches a keyup event.

  • key String | Symbol Name of key such as "b", :enter, :backspace

type(*keys) : Keyboard

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

  • text String | Array<String> | Array<Symbol> A text to type into a focused element, [:Shift, "s"], "tring"

modifiers(keys) : Integer

Returns bitfield for a given keys

  • keys Array<Symbol> :alt | :ctrl | :command | :shift

Cookies

browser.cookies

all : Hash<String, Cookie>

Returns cookies hash

browser.cookies.all # => {"NID"=>#<Ferrum::Cookies::Cookie:0x0000558624b37a40 @attributes={"name"=>"NID", "value"=>"...", "domain"=>".google.com", "path"=>"/", "expires"=>1583211046.575681, "size"=>178, "httpOnly"=>true, "secure"=>false, "session"=>false}>}

: Cookie

Returns cookie

  • value String
browser.cookies["NID"] # => <Ferrum::Cookies::Cookie:0x0000558624b67a88 @attributes={"name"=>"NID", "value"=>"...", "domain"=>".google.com", "path"=>"/", "expires"=>1583211046.575681, "size"=>178, "httpOnly"=>true, "secure"=>false, "session"=>false}>

set(**options) : Boolean

Sets given values as cookie

  • options Hash
    • :name String
    • :value String
    • :domain String
    • :expires Integer
    • :samesite String
    • :httponly Boolean
browser.cookies.set(name: "stealth", value: "omg", domain: "google.com") # => true

remove(**options) : Boolean

Removes given cookie

  • options Hash
    • :name String
    • :domain String
    • :url String
browser.cookies.remove(name: "stealth", domain: "google.com") # => true

clear : Boolean

Removes all cookies for current page

browser.cookies.clear # => true

Headers

browser.headers

get : Hash

Get all headers

set(headers) : Boolean

Set given headers. Eventually clear all headers and set given ones.

  • headers Hash key-value pairs for example "User-Agent" => "Browser"

add(headers) : Boolean

Adds given headers to already set ones.

  • headers Hash key-value pairs for example "Referer" => "http://example.com"

clear : Boolean

Clear all headers.

JavaScript

evaluate(expression, *args)

Evaluate and return result for given JS expression

  • expression String should be valid JavaScript
  • args Object you can pass arguments, though it should be a valid Node or a simple value.
browser.evaluate("[window.scrollX, window.scrollY]")

evaluate_async(expression, wait_time, *args)

Evaluate asynchronous expression and return result

  • expression String should be valid JavaScript
  • wait_time How long we should wait for Promise to resolve or reject
  • args Object you can pass arguments, though it should be a valid Node or a simple value.
browser.evaluate_async(%(arguments[0]({foo: "bar"})), 5) # => { "foo" => "bar" }

execute(expression, *args)

Execute expression. Doesn't return the result

  • expression String should be valid JavaScript
  • args Object you can pass arguments, though it should be a valid Node or a simple value.
browser.execute(%(1 + 1)) # => true

evaluate_on_new_document(expression)

Evaluate JavaScript to modify things before a page load

  • expression String should be valid JavaScript
browser.evaluate_on_new_document <<~JS
  Object.defineProperty(navigator, "languages", {
    get: function() { return ["tlh"]; }
  });
JS

add_script_tag(**options) : Boolean

  • options Hash
    • :url String
    • :path String
    • :content String
    • :type String - text/javascript by default
browser.add_script_tag(url: "http://example.com/stylesheet.css") # => true

add_style_tag(**options) : Boolean

  • options Hash
    • :url String
    • :path String
    • :content String
browser.add_style_tag(content: "h1 { font-size: 40px; }") # => true

bypass_csp(enabled) : Boolean

  • enabled Boolean, true by default
browser.bypass_csp # => true
browser.go_to("https://github.com/ruby-concurrency/concurrent-ruby/blob/master/docs-source/promises.in.md")
browser.refresh
browser.add_script_tag(content: "window.__injected = 42")
browser.evaluate("window.__injected") # => 42

Frames

frames : Array[Frame] | []

Returns all the frames current page have.

browser.go_to("https://www.w3schools.com/tags/tag_frame.asp")
browser.frames # =>
# [
#   #<Ferrum::Frame @id="C6D104CE454A025FBCF22B98DE612B12" @parent_id=nil @name=nil @state=:stopped_loading @execution_id=1>,
#   #<Ferrum::Frame @id="C09C4E4404314AAEAE85928EAC109A93" @parent_id="C6D104CE454A025FBCF22B98DE612B12" @state=:stopped_loading @execution_id=2>,
#   #<Ferrum::Frame @id="2E9C7F476ED09D87A42F2FEE3C6FBC3C" @parent_id="C6D104CE454A025FBCF22B98DE612B12" @state=:stopped_loading @execution_id=3>,
#   ...
# ]

main_frame : Frame

Returns page's main frame, the top of the tree and the parent of all frames.

frame_by(**options) : Frame | nil

Find frame by given options.

  • options Hash
    • :id String - Unique frame's id that browser provides
    • :name String - Frame's name if there's one
browser.frame_by(id: "C6D104CE454A025FBCF22B98DE612B12")

Frame

id : String

Frame's unique id.

parent_id : String | nil

Parent frame id if this one is nested in another one.

execution_id : Integer

Execution context id which is used by JS, each frame has it's own context in which JS evaluates.

name : String | nil

If frame was given a name it should be here.

state : Symbol | nil

One of the states frame's in:

  • :started_loading
  • :navigated
  • :stopped_loading

url : String

Returns current frame's location href.

browser.go_to("https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe")
frame = browser.frames[1]
frame.url # => https://interactive-examples.mdn.mozilla.net/pages/tabbed/iframe.html

title

Returns current frame's title.

browser.go_to("https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe")
frame = browser.frames[1]
frame.title # => HTML Demo: <iframe>

main? : Boolean

If current frame is the main frame of the page (top of the tree).

browser.go_to("https://www.w3schools.com/tags/tag_frame.asp")
frame = browser.frame_by(id: "C09C4E4404314AAEAE85928EAC109A93")
frame.main? # => false

current_url : String

Returns current frame's top window location href.

browser.go_to("https://www.w3schools.com/tags/tag_frame.asp")
frame = browser.frame_by(id: "C09C4E4404314AAEAE85928EAC109A93")
frame.current_url # => "https://www.w3schools.com/tags/tag_frame.asp"

current_title : String

Returns current frame's top window title.

browser.go_to("https://www.w3schools.com/tags/tag_frame.asp")
frame = browser.frame_by(id: "C09C4E4404314AAEAE85928EAC109A93")
frame.current_title # => "HTML frame tag"

body : String

Returns current frame's html.

browser.go_to("https://www.w3schools.com/tags/tag_frame.asp")
frame = browser.frame_by(id: "C09C4E4404314AAEAE85928EAC109A93")
frame.body # => "<html><head></head><body></body></html>"

doctype

Returns current frame's doctype.

browser.go_to("https://www.w3schools.com/tags/tag_frame.asp")
browser.main_frame.doctype # => "<!DOCTYPE html>"

set_content(html)

Sets a content of a given frame.

  • html String
browser.go_to("https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe")
frame = browser.frames[1]
frame.body # <html lang="en"><head><style>body {transition: opacity ease-in 0.2s; }...
frame.set_content("<html><head></head><body><p>lol</p></body></html>")
frame.body # => <html><head></head><body><p>lol</p></body></html>

Dialog

accept(text)

Accept dialog with given text or default prompt if applicable

  • text String

dismiss

Dismiss dialog

browser = Ferrum::Browser.new
browser.on(:dialog) do |dialog|
  if dialog.match?(/bla-bla/)
    dialog.accept
  else
    dialog.dismiss
  end
end
browser.go_to("https://google.com")

Animation

You can slow down or speed up CSS animations.

playback_rate : Integer

Returns playback rate for CSS animations, defaults to 1.

playback_rate = value

Sets playback rate of CSS animations

  • value Integer
browser = Ferrum::Browser.new
browser.playback_rate = 2000
browser.go_to("https://google.com")
browser.playback_rate # => 2000

Node

node? : Boolean

frame_id

frame

focus

focusable?

moving? : Boolean

wait_for_stop_moving

blur

type

click

hover

select_file

at_xpath

at_css

xpath

css

text

inner_text

value

property

attribute

evaluate

Thread safety

Ferrum is fully thread-safe. You can create one browser or a few as you wish and start playing around using threads. Example below shows how to create a few pages which share the same context. Context is similar to an incognito profile but you can have more than one, think of it like it's independent browser session:

browser = Ferrum::Browser.new
context = browser.contexts.create

t1 = Thread.new(context) do |c|
  page = c.create_page
  page.go_to("https://www.google.com/search?q=Ruby+headless+driver+for+Capybara")
  page.screenshot(path: "t1.png")
end

t2 = Thread.new(context) do |c|
  page = c.create_page
  page.go_to("https://www.google.com/search?q=Ruby+static+typing")
  page.screenshot(path: "t2.png")
end

t1.join
t2.join

context.dispose
browser.quit

or you can create two independent contexts:

browser = Ferrum::Browser.new

t1 = Thread.new(browser) do |b|
  context = b.contexts.create
  page = context.create_page
  page.go_to("https://www.google.com/search?q=Ruby+headless+driver+for+Capybara")
  page.screenshot(path: "t1.png")
  context.dispose
end

t2 = Thread.new(browser) do |b|
  context = b.contexts.create
  page = context.create_page
  page.go_to("https://www.google.com/search?q=Ruby+static+typing")
  page.screenshot(path: "t2.png")
  context.dispose
end

t1.join
t2.join

browser.quit

Development

After checking out the repo, run bundle install to install dependencies.

Then, run bundle exec rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub.

License

The gem is available as open source under the terms of the MIT License.