Marionette is a one-size-fits-all approach to WebDriver adapters. It works with most all web driver implementations, including:
Make sure you have Crystal installed. This is a Crystal project and Crystal is required for usage. If you don't have it installed, see https://crystal-lang.org.
Add Marionette to an existing project by adding the dependency to your
dependencies: marionette: github: watzon/marionette branch: master
shards install to download and install Marionette as a dependency.
WebDriver is a protocol which allows browser implementations to be remote controlled via a common interface. It's because of this functionality that frameworks like Marionette are possible. To use the protocol you first have to have installed one of the many WebDriver implementations, here are some of those:
GeckoDriver is implemented and supported by Mozilla directly.
ChromeDriver is implemented and supported by the Chromium Project.
OperaChromiumDriver is implemented and supported by Opera Software.
SafariDriver is implemented and supported directy by Apple. It comes pre-installed with Safari and Safari Technology Preview.
Microsoft is implementing and maintaining the Microsoft Edge WebDriver.
Only version 11 is supported, and it requires additional configuration.
Note: Marionette specific configuration instructions coming soon.
The goal of Marionette is simplicity, which is why it's written in Crystal. Once you have a webdriver installed and sitting comfortably on your path, using it couldn't be easier:
require "marionette" session = Marionette::WebDriver.create_session(:chrome) # Navigate to crystal-lang.org session.navigate("https://crystal-lang.org") # Start an action chain and perform it session.perform_actions do # Click the "INSTALL" link click ".main-actions a:nth-child(1)" end sleep 5 session.close
Different drivers have different capabilities available to them. To make setting them a little easier, there's the
DriverOptions module which is extended by
Marionette itself. Take, for instance, Chrome:
# Make this instance headless options = Marionette.chrome_options(args: ["headless"]) # Create a Chrome session session = Marionette::WebDriver.create_session(:chrome, capabilities: options)
args in this case are arguments to be passed to the browser itself rather than the driver. If you wish to pass arguments to the driver you can use the
args parameter in the
As shown above, you can initialize a new driver session for whatever driver you want using
Marionette::WebDriver.create_session, the first and most important argument to which is
:browser. Browser can be any of
If the driver for the chosen browser is installed under its usual name that should be all you need to do, if not you may need to provide the binary location via the
:exe_path argument. Other notable arguments are:
:port- sets the port you want the driver to listen on
:env- a hash of environment variables for the driver to be aware of
:args- a string array of arguments to pass to the webdriver process
:options- a JSON compatible structure containing browser options. see here for some nice helpers.
The first thing you will want to do after launching a browser is to open your website. This can be achieved in a single line:
You can read the current URL from the browser’s address bar using:
session.current_url # => https://crystal-lang.org
Pressing the browser’s back button:
Pressing the browser’s forward button:
Refresh the current page:
You can read the current page title from the browser:
session.title # => Crystal | The Crystal Programming Language
WebDriver does not make the distinction between windows and tabs. If your site opens a new tab or window, Marionette will let you work with it using a window handle. Each window has a unique identifier which remains persistent in a single session.
You can get the currently active window using:
This returns a
Window instance containing a handle and allowing certain functions to be performed directly on the window instance.
You can get an array of all currently opened windows using:
You can create a new window or tab using:
session.new_window(:window) # default session.new_window(:tab) # Or using the Window object Marionette::Window.new(:window) # default Marionette::Window.new(:tab)
To interact with other windows you have to switch to them, this can be done with:
session.switch_to_window(window) # Or using the Window object window.switch
When you are finished with a window or tab and it is not the last window or tab open in your browser, you should close it and switch back to the window you were using previously:
session.close_window(window) # Or using the Window object window.close
Think of this is a shortcut to
#close_window but for the currently active window:
When you are finished with the browser session you should call
stop, instead of
Stop will be automatically closed on process exit.
Frames are a now deprecated means of building a site layout from multiple documents on the same domain. You are unlikely to work with them unless you are working with an pre HTML5 webapp. Iframes allow the insertion of a document from an entirely different domain, and are still commonly used.
If you need to work with frames or iframes, WebDriver allows you to work with them in the same way. Consider a button within an iframe. If we inspect the element using the browser development tools, we might see the following:
<div id="modal"> <iframe id="buttonframe" name="myframe" src="https://watzon.github.io"> <button>Click here</button> </iframe> </div>
If it was not for the iframe we would expect to click on the button using something like:
However, if there are no buttons outside of the iframe, you might instead get a no such element error. This happens because Marionette is only aware of the elements in the top level document. To interact with the button, we will need to first switch to the frame, in a similar way to how we switch windows. WebDriver offers three ways of switching to a frame.
switch_to_frame session method allows us to tell the WebDriver that we want to switch the page context to the given frame/iframe:
# Find the element iframe = session.find_element!("#modal>iframe") # Switch to the frame session.switch_to_frame(iframe) # Now we can click the button session.find_element!("button").click
If you're in a nested set of frames you can switch back to the parent frame using:
When you're done inside a frame and want to get back to the normal document context you can use:
Screen resolution can impact how your web application renders, so WebDriver provides mechanisms for moving and resizing the browser window.
You can fetch window dimensions either collectively or individually:
# First get the current window window = session.current_window # Access dimensions individually width = window.width height = window.height # Or collectively as a Size object window.size # => Size(width: 800.0, height: 600.0)
To resize the window:
window.resize_to(600, 800) # Or using an existing Size object `size` window.size = size
You can fetch the coordinates of the top left corner of the browser window:
window.position # => Location(x: 0.0, y: 0.0)
You can also easily set the position of the window:
window.move_to(250, 250) # Or using a Location object `location` window.position = location
To maximize the given window:
To minimize the given window:
To make the given window full screen:
Element represents a DOM element. WebElements can be found by searching from the document root using a WebDriver instance, or by searching under another
WebDriver API provides built-in methods to find the WebElements which are based on different properties like ID, Name, Class, XPath, CSS Selectors, link Text, etc.
Get and return the active element:
find_element! are used to find and store references to page elements. The only difference between the two is that
find_element! will throw an exception if the element is not found and will not be nil, whereas
find_element will return nil if the element is not found.
# Get the search box element by name search_bar = session.find_element!("q", :name) # Peform an action search_bar.send_keys("Crystal programming language") # Click the submit button (using the default :css option this time) session.find_element!("button.submit").click
Used to find an array of elements matching the given selector:
# Get all elements with the tag name "p" elements = session.find_elements("p", :tag_name) elements.each do |el| puts el.text end
Used to find a child element within the context of parent element. Like
find_element it has raising and non-raising varients:
# Find the search form form = session.find_element!("form", :tag_name) # Find the form's child search box search_bar = form.find_child!("q", :name) search_bar.send_keys("Crystal programming language")
element = session.find_element!("div", :tag_name) paragraphs = element.find_children("p", :tag_name) paragraphs.each do |para| puts para.text end