和我一起学 Selenium WebDriver（4）——基础篇

【1、如何处理异步加载】

对于异步加载的捕获，其实就是一个等待的过程，这在之前的例子中早已看过，只不过需要特别说明一下 WebDriverWait，当超时后就会抛出异常，所以如果你的测试中对于这个部分不需要抛出异常的话，那么最好用 try catch 包起来。

这次利用 zTree 异步加载的Demo做测试，同时分别利用 WebElement 的 click 方法 和 zTree 的 expandNode 方法展开节点，进行异步加载。使用起来并不困难，直接看代码即可。

Java代码

1. package lesson4;
3. import static org.junit.Assert.*;
5. import org.junit.AfterClass;
6. import org.junit.BeforeClass;
7. import org.junit.Test;
8. import org.openqa.selenium.JavascriptExecutor;
9. import org.openqa.selenium.WebDriver;
10. import org.openqa.selenium.WebElement;
11. import org.openqa.selenium.firefox.FirefoxDriver;
12. import org.openqa.selenium.support.ui.ExpectedCondition;
13. import org.openqa.selenium.support.ui.WebDriverWait;
15. public class ExampleForAjax {
17. static WebDriver driver;
19. @BeforeClass
20. public static void init() {
21. System.out.println("init...");
22. // 如果你的 FireFox 没有安装在默认目录，那么必须在程序中设置
23. System.setProperty("webdriver.firefox.bin", "D:\\Program Files\\Mozilla Firefox\\firefox.exe");
24. // 创建一个 FireFox 的浏览器实例
25. driver = new FirefoxDriver();
26. }
28. @Test
29. public void test() {
30. // 让浏览器访问 zTree Demo
31. driver.get("http://www.ztree.me/v3/demo/cn/core/async.html");
33. // 等待 zTree 初始化完毕，Timeout 设置10秒
34. try {
35. (new WebDriverWait(driver, 10, 500)).until(new ExpectedCondition<Boolean>() {
36. public Boolean apply(WebDriver d) {
37. WebElement element = (WebElement) ((JavascriptExecutor)driver).executeScript("return $('#treeDemo li').get(0);");
38. return element != null;
39. }
40. });
42. } catch(Exception e) {
43. e.printStackTrace();
44. }
46. ((JavascriptExecutor)driver).executeScript("window.zTreeObj = $.fn.zTree.getZTreeObj('treeDemo');");
48. //判断节点总数
49. Long count =(Long) ((JavascriptExecutor)driver).executeScript("return window.zTreeObj.transformToArray(window.zTreeObj.getNodes()).length;");
50. assertTrue(count == 4);
52. //利用 expandNode 方法展开第一个父节点
53. ((JavascriptExecutor)driver).executeScript("window.zTreeNode = window.zTreeObj.getNodeByParam('isParent', true); window.zTreeObj.expandNode(window.zTreeNode, true);");
54. try {
55. (new WebDriverWait(driver, 10, 500)).until(new ExpectedCondition<Boolean>() {
56. public Boolean apply(WebDriver d) {
57. Boolean isAjaxing = (Boolean) ((JavascriptExecutor)driver).executeScript("return !!window.zTreeNode.isAjaxing;");
58. return !isAjaxing;
59. }
60. });
62. } catch(Exception e) {
63. e.printStackTrace();
64. }
65. //判断节点总数
66. count =(Long) ((JavascriptExecutor)driver).executeScript("return window.zTreeObj.transformToArray(window.zTreeObj.getNodes()).length;");
67. assertTrue(count == 8);
69. //模拟 click 事件 单击节点 +/- 号展开
70. WebElement element = (WebElement) ((JavascriptExecutor)driver).executeScript("window.zTreeNode = window.zTreeNode.children[0]; return $('#' + window.zTreeNode.tId + '_switch').get(0);");
71. element.click();
73. // 展开第一个子节点
74. ((JavascriptExecutor)driver).executeScript("window.zTreeObj.expandNode(window.zTreeNode, true);");
75. try {
76. (new WebDriverWait(driver, 10, 500)).until(new ExpectedCondition<Boolean>() {
77. public Boolean apply(WebDriver d) {
78. Boolean isAjaxing = (Boolean) ((JavascriptExecutor)driver).executeScript("return !!window.zTreeNode.isAjaxing;");
79. return !isAjaxing;
80. }
81. });
83. } catch(Exception e) {
84. e.printStackTrace();
85. }
86. //判断节点总数
87. count =(Long) ((JavascriptExecutor)driver).executeScript("return window.zTreeObj.transformToArray(window.zTreeObj.getNodes()).length;");
88. assertTrue(count == 12);
90. }
92. @AfterClass
93. public static void destory() {
94. System.out.println("destory...");
95. //关闭浏览器
96. driver.quit();
97. }
98. }