Question

I have the following html code:

I saw that for Watir-webdriver the “Watir::Image.file_size” method is not currently supported.
I found out that the “Watir-Classic/Image.rb” has the same method, and it seems that can be used.

# this method returns the filesize of the image, as an int
def file_size
  assert_exists
  @o.invoke("fileSize").to_i
end

I created a method that should retrieve the image size, but it seems I am not initializing the object correctly. Here is my code from the method:

img_src="/location/on_the_server/image"
chart_image = Watir::Image.new(:src, img_src)
puts chart_image.file_size

The problem is that I receive the following error:

"ArgumentError: invalid argument "/location/on_the_server/image""

I saw that for initialization the object requires (container,specifiers). I tried to change the initialization line to “chart_image = Watir::Image.new(img_src, :src)” but the error keeps appearing.

Could anyone tell me what am I doing wrong?

Is there another way to get the file size of an image from a website?

Thank you.

Answer 1

You should not be initializing Watir::Image directly. Instead, you should use the image() method of a browser or element object.

#Assuming that browser = Watir::Browser that is open
img_src="/location/on_the_server/image"
chart_image = browser.image(:src, img_src)
puts chart_image.file_size

Update – Download Image to Determine File Size:

You could download the image using with open-uri (or similar) and then use Ruby’s File class to determine the size:

require 'watir-webdriver'
require "open-uri"

#Specify where to save the image
save_file = 'C:\Users\my_user\Desktop\image.png'

#Get the src of the image you want. In this example getting the first image on Google.
browser = Watir::Browser.new
browser.goto('www.google.ca')
image_location = browser.image.src

#Save the file
File.open(save_file, 'wb') do |fo|
  fo.write open(image_location, :ssl_verify_mode => OpenSSL::SSL::VERIFY_NONE).read
end

#Output the size
puts File.size(save_file).size