Question

我正在使用python webdriver，我试图让系统等到密码字段的边框颜色在单击提交按钮后发生变化。颜色从一个渐变到另一个，我可以使用它来获得所需的结果： -

password_border_colour_after_click = ""
count = 0
while password_border_colour_after_click != "rgba(169, 68, 66, 1)":
    password_border_colour_after_click = self.driver.find_element_by_name("password").value_of_css_property('border-bottom-color')
    time.sleep(0.1)
    count += 1
    if password_border_colour_after_click == "rgba(169, 68, 66, 1)":
        break
    elif count > 50:
        break
assert password_border_colour_after_click == "rgba(169, 68, 66, 1)"

感觉有点笨拙，可能是糟糕的代码所以我认为必须有一种方法可以在wait命令中打包它，但我无法正确使用语法。

有可能吗？

Answer 1

TL; DR;

Selenium API有一个“等待......”功能：

http://selenium-python.readthedocs.io/waits.html

实施expected_condition，然后将其与wait

合并

element = WebDriverWait(driver, 10)
             .until(custom_expected_condition((By.ID, 'search-input'), argA, argB))

等待

很高兴知道“等待”是同步运行的（阻塞线程），并且可以与下列之一结合使用，开箱即用：

title_is

title_contains

presence_of_element_located

visibility_of_element_located

visibility_of

presence_of_all_elements_located

text_to_be_present_in_element

text_to_be_present_in_element_value

frame_to_be_available_and_switch_to_it

invisibility_of_element_located

element_to_be_clickable

staleness_of

element_to_be_selected

element_located_to_be_selected

element_selection_state_to_be

element_located_selection_state_to_be

alert_is_present

正如您所看到的那样，没有element_has_style_value条件，但是总是可以通过自己的实现扩展“等待”。

在文档中，自定义预期条件如下：

class element_has_css_class(object):
  """An expectation for checking that an element has a particular css class.

  locator - used to find the element
  returns the WebElement once it has the particular css class
  """
  def __init__(self, locator, css_class):
    self.locator = locator
    self.css_class = css_class

  def __call__(self, driver):
    element = driver.find_element(*self.locator)   # Finding the referenced element
    if self.css_class in element.get_attribute("class"):
        return element
    else:
        return False

它的用法是：

# Wait until an element with id='myNewInput' has class 'myCSSClass'
wait = WebDriverWait(driver, 10)
element = wait.until(element_has_css_class((By.ID, 'myNewInput'), "myCSSClass"))

可能的解决方案

将所有内容放在一起，形成资产页面：https://output.jsbin.com/xutipu

可以实现这一点：

class element_has_css_value(object):
  """An expectation for checking that an element has a particular css property and value.

  locator - used to find the element
  returns the WebElement once it has the particular css property and value
  """
  def __init__(self, locator, css_property, css_value):
    self.locator = locator
    self.css_property = css_property
    self.css_value = css_value

  def matchPropertyAndValue(self, css_property, css_value):

      return css_property == self.css_property and css_value  == self.css_value;

  def extractPropertyAndValue(self, cssStatement):
    keyValue = cssStatement.split(':')
    if len(keyValue) == 2:
        key = keyValue[0].strip();
        value = keyValue[1].strip();
        return (key, value)
    return (None, None)

  def findProperty(self, entries):
    foundProperty = False
    for entry in entries:
      (css_property, css_value) = self.extractPropertyAndValue(entry)
      if css_value is None:
          continue
      foundProperty = self.matchPropertyAndValue(css_property, css_value);
      if foundProperty :
          break;
    return foundProperty

  def __call__(self, driver):
    element = driver.find_element(*self.locator)   # Finding the referenced element
    styles = element.get_attribute("style")
    entries = styles.split(';')
    foundProperty = self.findProperty(entries);

    if foundProperty :
        return element
    else:
        return False

并像这样使用它：

from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
driver = webdriver.Chrome()
driver.get("https://output.jsbin.com/xutipu")
button = None;
try:
    button = WebDriverWait(driver, 10).until(
        EC.presence_of_element_located((By.ID, "search-button"))
    )
except e:
    print(e);
    driver.quit()

button.send_keys(Keys.RETURN)

try :
    wait = WebDriverWait(driver, 10)
    element = wait.until(element_has_css_value((By.ID, 'search-input'), "border-color", "rgb(169, 68, 66)"))
    assert element;
    print('Success');
finally:
    driver.quit()

Answer 2

我不知道如何在Python中执行此操作，因为我并不熟悉该语言，但在C＃中，您可以创建类似自定义ExpectedConditions的委托函数，您可以使用使用WebDriverWait类。

WebDriverWait类在抛出异常之前等待n秒。

C＃中的示例（伪）代码：

public static class CustomExpectedConditions
{
    public static Func<IWebDriver, bool> ElementAttributeContains(By locator, string attributeName, string expectedValue)
    {
        return (driver) => driver.FindElement(locator).GetAttribute(attributeName).Contains(expectedValue);
    }
}

这允许您使用它：

var wait = new WebDriverWait(driver, TimeSpan.FromSeconds(5));
wait.Until(CustomExpectedConditions.ElementAttributeContains(By.Name("password"), "style", "rgba(169, 68, 66, 1)"));

我在Python中找到了自定义预期条件的示例代码：

class element_has_css_class(object):
"""An expectation for checking that an element has a particular css class.

locator - used to find the element
returns the WebElement once it has the particular css class
"""
def __init__(self, locator, css_class):
  self.locator = locator
  self.css_class = css_class

def __call__(self, driver):
  element = driver.find_element(*self.locator)   # Finding the referenced element
  if self.css_class in element.get_attribute("class"):
      return element
  else:
      return False

# Wait until an element with id='myNewInput' has class 'myCSSClass'
wait = WebDriverWait(driver, 10)
element = wait.until(element_has_css_class((By.ID, 'myNewInput'), "myCSSClass"))

希望这会让你开始朝着正确的方向前进

在声明更改之前等待CSS属性更改

2 个答案:

TL; DR;

等待

可能的解决方案