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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.
page.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.
page.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.
page.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
page.add_script_tag(url: "http://example.com/stylesheet.css") # => true

add_style_tag(**options) : Boolean​

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

bypass_csp(**options) : Boolean​

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

disable_javascript​

Disables Javascripts from the loaded HTML source. You can still evaluate JavaScript with evaluate or execute. Returns nothing.

page.disable_javascript