如何在 Ruby 中使用 selenium-webdriver/capybara 截取完整浏览器页面及其元素的屏幕截图？

Question

我正在研究屏幕截图自动化。 特别是，我正在努力实现以下目标：

1. 提示用户链接到网站上的不同页面 X
2. 提示用户输入 class 名称 Y
3. 我应该能够访问网站 X 登录页面，提供登录详细信息（假设它们是已知的），单击“提交”按钮，这应该会将我重定向到“主页”页面
4. 然后我查看用户提供的链接列表，访问每个页面并截取具有 class Y（或整个页面）的所有元素的屏幕截图
5. 将它们保存在当前目录中

请点击链接查看视觉展示

我想在 Ruby 中实施以下解决方案（但我也愿意接受任何其他建议）：

1) 截取网站 X 上整个可滚动页面的屏幕截图 2) 找到 class Y 的元素，特别是它在页面上的位置、宽度和高度。 3）裁剪完整的屏幕截图，以便只显示所需的元素

问题如下：

我无法截取整个页面的屏幕截图，我只能截取屏幕可见区域的屏幕截图。

这是我尝试过的以及相应的问题：

解决方案 1（Ruby - 一般）：

require 'selenium-webdriver'

driver = Selenium::WebDriver.for :firefox #:chrome

driver.navigate.to "https://some_very-very_long_page_on_website_X"
driver.manage.window.maximize # <- works for firefox only
driver.save_screenshot('picture1.png')

# Problem: it captures only the viewable area, 
# not an entire page

解决方案 2（Ruby - Window 调整大小）：

require 'selenium-webdriver'

driver = Selenium::WebDriver.for :firefox #:chrome
driver.navigate.to 'https://some_very-very_long_page_on_website_X'

width  = driver.execute_script("return Math.max(document.body.scrollWidth,document.body.offsetWidth,document.documentElement.clientWidth,document.documentElement.scrollWidth,document.documentElement.offsetWidth);")
height = driver.execute_script("return Math.max(document.body.scrollHeight,document.body.offsetHeight,document.documentElement.clientHeight,document.documentElement.scrollHeight,document.documentElement.offsetHeight);")

driver.manage.window.resize_to(width, height) # <- resizes the window
driver.manage.window.full_screen  # <- works, but in chrome throws:
                                  # full_screen': undefined method `full_screen_window'

picture = driver.screenshot_as(:png)

File.open('picture2.png', 'w+') do |fh|
  fh.write picture
end

driver.quit

# Resizes the window only to the viewable area, as a result,
# it captures the viewable area only

解决方案 3（Ruby-watir 宝石）：

require 'watir'

b = Watir::Browser.new
b.goto 'https://some_very-very_long_page_on_website_X'
b.screenshot.save("picture.png")

# Issues: does not capture the entire page

解决方案 4（Ruby - 单元素捕获）

require "selenium-webdriver"

driver = Selenium::WebDriver.for :chrome

driver.get'https://some_very-very_long_page_on_website_X'

driver.manage.window.maximize
driver.execute_script("document.getElementById('some_id').scrollIntoView();")
driver.save_screenshot "picture3.png"

# Problem: captures the element, which I need, but only if its size is less than
# the viewable area

解决方案 5（Ruby - 缩放）

require "selenium-webdriver"

driver = Selenium::WebDriver.for :firefox

driver.get 'https://some_very-very_long_page_on_website_X'

driver.manage.window.maximize
driver.execute_script("document.body.style.transform = 'scale(0.5)'")
#driver.execute_script("document.body.style.zoom = '50%'") <-- transform works better than zoom

driver.save_screenshot "picture3.png"

#Issues: works, but not for very long pages, in addition it may change the layout
# (some elements may start to overlap each other)
# Also I am not sure how to calculate the value of the parameter for scale
# for very long pages

解决方案 6 -（Ruby - 无头 Chrome 调整大小）

require "selenium-webdriver"

options = Selenium::WebDriver::Chrome::Options.new
options.add_argument('--headless')
driver = Selenium::WebDriver.for :chrome, options: options

driver.get "https://some_very-very_long_page_on_website_X"

width  = driver.execute_script("return Math.max(document.body.scrollWidth,document.body.offsetWidth,document.documentElement.clientWidth,document.documentElement.scrollWidth,document.documentElement.offsetWidth);")
height = driver.execute_script("return Math.max(document.body.scrollHeight,document.body.offsetHeight,document.documentElement.clientHeight,document.documentElement.scrollHeight,document.documentElement.offsetHeight);")

driver.manage.window.resize_to(width+2000, height+2000) # <-- if I do not have +2000, page looks squished
                                                        # the greater the number, the greater the quality
                                                        # but also the more white space is around the page
                                                        # and the picture is heavier
driver.manage.window.maximize

sleep 5             # <--- required waiting for page loading 
driver.save_screenshot "full.png"

# One of the best approaches, but it is not clear to me how to calculate 
# the parameters for resize_to

工具/技术：

• selenium-webdriver (3.12.0)
• Chrome 驱动程序 2.40

Answer 1

您可以使用watir-screenshot-stitch gem来完成您想要的操作：

require 'watir-screenshot-stitch'
b = Watir::Browser.new :firefox
b.goto "https://github.com/mozilla/geckodriver/issues/570"
b.base64_geckodriver # => returns a base64-encoded full page screenshot.

Answer 2

您可以使用 Firefox 和"webdrivers" gem 来执行此操作，它将"selenium-webdriver"安装为依赖项：

require "webdrivers/geckodriver"

driver = Selenium::WebDriver.for :firefox
driver.get("https://openai.com/api/")
File.binwrite("screenshot.png", driver.screenshot_as(:png, full_page: true))
driver.quit