Evaluating JavaScript | Playwright Python

# A primitive value.
page.evaluate('num => num', 42)
# An array.
page.evaluate('array => array.length', [1, 2, 3])
# An object.
page.evaluate('object => object.foo', { 'foo': 'bar' })
# A single handle.
button = page.evaluate_handle('window.button')
page.evaluate('button => button.textContent', button)
# Alternative notation using JSHandle.evaluate.
button.evaluate('(button, from) => button.textContent.substring(from)', 5)
# Object with multiple handles.
button1 = page.evaluate_handle('window.button1')
button2 = page.evaluate_handle('.button2')
page.evaluate("""o => o.button1.textContent + o.button2.textContent""",
    { 'button1': button1, 'button2': button2 })
# Object destructuring works. Note that property names must match
# between the destructured object and the argument.
# Also note the required parenthesis.
page.evaluate("""
    ({ button1, button2 }) => button1.textContent + button2.textContent""",
    { 'button1': button1, 'button2': button2 })
# Array works as well. Arbitrary names can be used for destructuring.
# Note the required parenthesis.
page.evaluate("""
    ([b1, b2]) => b1.textContent + b2.textContent""",
    [button1, button2])
# Any mix of serializables and handles works.
page.evaluate("""
    x => x.button1.textContent + x.list[0].textContent + String(x.foo)""",
    { 'button1': button1, 'list': [button2], 'foo': None })