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Support features

针对更高层面功能的额外支持类.

1: Waiting with Expected Conditions
2: 命令监听器
3: 同颜色一起工作
4: 线程守卫
5: 使用选择列表元素

Selenium的核心库试图提供底层以及普适的功能. 每种语言的支持类都为常见交互提供特定的包装器, 可用于简化某些行为.

1 - Waiting with Expected Conditions

These are classes used to describe what needs to be waited for.

Expected Conditions are used with Explicit Waits. Instead of defining the block of code to be executed with a lambda, an expected conditions method can be created to represent common things that get waited on. Some methods take locators as arguments, others take elements as arguments.

These methods can include conditions such as:

element exists
element is stale
element is visible
text is visible
title contains specified value

Expected Conditions Documentation

Add Example

[Expected Conditions Documentation](https://www.selenium.dev/selenium/docs/api/py/webdriver_support/selenium.webdriver.support.expected_conditions.html)

Add Example

.NET stopped supporting Expected Conditions in Selenium 4 to minimize maintenance hassle and redundancy.

Ruby makes frequent use of blocks, procs and lambdas and does not need Expected Conditions classes

Add Example

2 - 命令监听器

允许您在每次发送特定 Selenium 命令时执行自定义操作

Add Example

3 - 同颜色一起工作

在测试中, 您偶尔会需要验证某事物的颜色；问题是网络上的颜色定义不是个常量. 如果有一种简单的方法可以比较颜色的十六进制与RGB呈现, 或者颜色的RGBA与HSLA呈现, 岂不美哉?

不用担心有一个解决方案：Color 类!

首先, 您需要导入该类:

import org.openqa.selenium.support.Color;
  

from selenium.webdriver.support.color import Color
  

// This feature is not implemented - Help us by sending a pr to implement this feature

include Selenium::WebDriver::Support
  

// This feature is not implemented - Help us by sending a pr to implement this feature

import org.openqa.selenium.support.Color

您现在可以开始创建颜色对象. 每个颜色对象都需要使用您颜色的字符串定义来创建. 支持的颜色定义如下:

private final Color HEX_COLOUR = Color.fromString("#2F7ED8");
private final Color RGB_COLOUR = Color.fromString("rgb(255, 255, 255)");
private final Color RGB_COLOUR = Color.fromString("rgb(40%, 20%, 40%)");
private final Color RGBA_COLOUR = Color.fromString("rgba(255, 255, 255, 0.5)");
private final Color RGBA_COLOUR = Color.fromString("rgba(40%, 20%, 40%, 0.5)");
private final Color HSL_COLOUR = Color.fromString("hsl(100, 0%, 50%)");
private final Color HSLA_COLOUR = Color.fromString("hsla(100, 0%, 50%, 0.5)");
  

HEX_COLOUR = Color.from_string('#2F7ED8')
RGB_COLOUR = Color.from_string('rgb(255, 255, 255)')
RGB_COLOUR = Color.from_string('rgb(40%, 20%, 40%)')
RGBA_COLOUR = Color.from_string('rgba(255, 255, 255, 0.5)')
RGBA_COLOUR = Color.from_string('rgba(40%, 20%, 40%, 0.5)')
HSL_COLOUR = Color.from_string('hsl(100, 0%, 50%)')
HSLA_COLOUR = Color.from_string('hsla(100, 0%, 50%, 0.5)')
  

// This feature is not implemented - Help us by sending a pr to implement this feature

HEX_COLOUR = Color.from_string('#2F7ED8')
RGB_COLOUR = Color.from_string('rgb(255, 255, 255)')
RGB_COLOUR = Color.from_string('rgb(40%, 20%, 40%)')
RGBA_COLOUR = Color.from_string('rgba(255, 255, 255, 0.5)')
RGBA_COLOUR = Color.from_string('rgba(40%, 20%, 40%, 0.5)')
HSL_COLOUR = Color.from_string('hsl(100, 0%, 50%)')
HSLA_COLOUR = Color.from_string('hsla(100, 0%, 50%, 0.5)')
  

// This feature is not implemented - Help us by sending a pr to implement this feature

private val HEX_COLOUR = Color.fromString("#2F7ED8")
private val RGB_COLOUR = Color.fromString("rgb(255, 255, 255)")
private val RGB_COLOUR_PERCENT = Color.fromString("rgb(40%, 20%, 40%)")
private val RGBA_COLOUR = Color.fromString("rgba(255, 255, 255, 0.5)")
private val RGBA_COLOUR_PERCENT = Color.fromString("rgba(40%, 20%, 40%, 0.5)")
private val HSL_COLOUR = Color.fromString("hsl(100, 0%, 50%)")
private val HSLA_COLOUR = Color.fromString("hsla(100, 0%, 50%, 0.5)")
  

Color类还支持在以下网址中指定的所有基本颜色定义 http://www.w3.org/TR/css3-color/#html4.

private final Color BLACK = Color.fromString("black");
private final Color CHOCOLATE = Color.fromString("chocolate");
private final Color HOTPINK = Color.fromString("hotpink");
  

BLACK = Color.from_string('black')
CHOCOLATE = Color.from_string('chocolate')
HOTPINK = Color.from_string('hotpink')
  

// This feature is not implemented - Help us by sending a pr to implement this feature

BLACK = Color.from_string('black')
CHOCOLATE = Color.from_string('chocolate')
HOTPINK = Color.from_string('hotpink')
  

// This feature is not implemented - Help us by sending a pr to implement this feature

private val BLACK = Color.fromString("black")
private val CHOCOLATE = Color.fromString("chocolate")
private val HOTPINK = Color.fromString("hotpink")
  

如果元素上未设置颜色, 则有时浏览器会返回“透明”的颜色值. Color类也支持此功能:

private final Color TRANSPARENT = Color.fromString("transparent");
  

TRANSPARENT = Color.from_string('transparent')
  

// This feature is not implemented - Help us by sending a pr to implement this feature

TRANSPARENT = Color.from_string('transparent')
  

// This feature is not implemented - Help us by sending a pr to implement this feature

private val TRANSPARENT = Color.fromString("transparent")
  

现在, 您可以安全地查询元素以获取其颜色/背景色, 任何响应都将被正确解析并转换为有效的Color对象:

Color loginButtonColour = Color.fromString(driver.findElement(By.id("login")).getCssValue("color"));

Color loginButtonBackgroundColour = Color.fromString(driver.findElement(By.id("login")).getCssValue("background-color"));

login_button_colour = Color.from_string(driver.find_element(By.ID,'login').value_of_css_property('color'))

login_button_background_colour = Color.from_string(driver.find_element(By.ID,'login').value_of_css_property('background-color'))

// This feature is not implemented - Help us by sending a pr to implement this feature

login_button_colour = Color.from_string(driver.find_element(id: 'login').css_value('color'))

login_button_background_colour = Color.from_string(driver.find_element(id: 'login').css_value('background-color'))

// This feature is not implemented - Help us by sending a pr to implement this feature

val loginButtonColour = Color.fromString(driver.findElement(By.id("login")).getCssValue("color"))

val loginButtonBackgroundColour = Color.fromString(driver.findElement(By.id("login")).getCssValue("background-color"))

然后, 您可以直接比较颜色对象:

assert loginButtonBackgroundColour.equals(HOTPINK);
  

assert login_button_background_colour == HOTPINK

// This feature is not implemented - Help us by sending a pr to implement this feature

assert(login_button_background_colour == HOTPINK)
  

// This feature is not implemented - Help us by sending a pr to implement this feature

assert(loginButtonBackgroundColour.equals(HOTPINK))
  

或者, 您可以将颜色转换为以下格式之一并执行静态验证:

assert loginButtonBackgroundColour.asHex().equals("#ff69b4");
assert loginButtonBackgroundColour.asRgba().equals("rgba(255, 105, 180, 1)");
assert loginButtonBackgroundColour.asRgb().equals("rgb(255, 105, 180)");
  

assert login_button_background_colour.hex == '#ff69b4'
assert login_button_background_colour.rgba == 'rgba(255, 105, 180, 1)'
assert login_button_background_colour.rgb == 'rgb(255, 105, 180)'
  

// This feature is not implemented - Help us by sending a pr to implement this feature

assert(login_button_background_colour.hex == '#ff69b4')
assert(login_button_background_colour.rgba == 'rgba(255, 105, 180, 1)')
assert(login_button_background_colour.rgb == 'rgb(255, 105, 180)')
  

// This feature is not implemented - Help us by sending a pr to implement this feature

assert(loginButtonBackgroundColour.asHex().equals("#ff69b4"))
assert(loginButtonBackgroundColour.asRgba().equals("rgba(255, 105, 180, 1)"))
assert(loginButtonBackgroundColour.asRgb().equals("rgb(255, 105, 180)"))
  

颜色不再是问题.

4 - 线程守卫

此类仅在Java中可用

ThreadGuard检查是否仅从创建驱动程序的同一线程中调用了驱动程序. 线程问题 (尤其是在Parallel中运行测试时) 可能遇到神秘并且难以诊断错误. 使用此包装器可以防止此类错误,
并且在发生此类情况时会抛出异常.

以下的示例模拟一种线程冲突的情况:

public class DriverClash {
  //thread main (id 1) created this driver
  private WebDriver protectedDriver = ThreadGuard.protect(new ChromeDriver());

  static {
    System.setProperty("webdriver.chrome.driver", "<Set path to your Chromedriver>");
  }

  //Thread-1 (id 24) is calling the same driver causing the clash to happen
  Runnable r1 = () -> {protectedDriver.get("https://selenium.dev");};
  Thread thr1 = new Thread(r1);

  void runThreads(){
    thr1.start();
  }

  public static void main(String[] args) {
    new DriverClash().runThreads();
  }
}

结果如下所示:

Exception in thread "Thread-1" org.openqa.selenium.WebDriverException:
Thread safety error; this instance of WebDriver was constructed
on thread main (id 1)and is being accessed by thread Thread-1 (id 24)
This is not permitted and *will* cause undefined behaviour

正如示例所示:

protectedDriver 将在主线程中创建
我们使用Java的 Runnable 启动一个新进程, 并使用一个新的 Thread 运行该进程
这两个 Thread 都会发生冲突, 因为主线程的内存中没有 protectedDriver
ThreadGuard.protect 会抛出异常

注意:

这不能代替并发运行时使用 ThreadLocal 管理驱动程序的需求.

5 - 使用选择列表元素

与其他元素相比，选择列表具有特殊的行为.

Select对象现在将为您提供一系列命令, 用于允许您与 <select> 元素进行交互.

如果您使用的是 Java 或 .NET，请确保您在代码中已正确加载所需的包. 您可以通过GitHub查看下面示例的完整代码.

请注意，此类仅适用于 HTML 元素 select 和 option. 这个类将不适用于那些通过 div 或 li 并使用JavaScript遮罩层设计的下拉列表.

类型

选择方法的行为可能会有所不同，具体取决于正在使用的 <select> 元素的类型.

单选

这是标准的下拉对象，其只能选定一个选项.

<select name="selectomatic">
    <option selected="selected" id="non_multi_option" value="one">One</option>
    <option value="two">Two</option>
    <option value="four">Four</option>
    <option value="still learning how to count, apparently">Still learning how to count, apparently</option>
</select>

复选

此选择列表允许同时选定和取消选择多个选项. 这仅适用于具有 multiple 属性的 <select>元素.

<select name="multi" id="multi" multiple="multiple">
    <option selected="selected" value="eggs">Eggs</option>
    <option value="ham">Ham</option>
    <option selected="selected" value="sausages">Sausages</option>
    <option value="onion gravy">Onion gravy</option>
</select>

构建类

首先定位一个 <select> 元素, 然后借助其初始化一个Select 对象. 请注意, 从 Selenium 4.5 开始, 您无法针对禁用的 <select> 元素构建 Select 对象.

        WebElement selectElement = driver.findElement(By.name("selectomatic"));
        Select select = new Select(selectElement);

Support features

1 - Waiting with Expected Conditions

2 - 命令监听器

3 - 同颜色一起工作

4 - 线程守卫

注意:

5 - 使用选择列表元素

类型

单选

复选

构建类

选项列表

全部选项

选中的选项

选项

文本

值

序号

禁用的选项

取消选择选项

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