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







package lesson4;

import static org.junit.Assert.*;

import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;
import org.openqa.selenium.JavascriptExecutor;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;

import org.openqa.selenium.support.ui.ExpectedCondition;

import org.openqa.selenium.support.ui.WebDriverWait;

public class ExampleForAjax {

static WebDriver driver;

@BeforeClass
public static
void init() {
System.out.println("init...");
// 如果你的 FireFox 没有安装在默认目录，那么必须在程序中设置
System.setProperty("webdriver.firefox.bin",
"D:\\Program Files\\Mozilla Firefox\\firefox.exe");
// 创建一个 FireFox 的浏览器实例
driver = new FirefoxDriver();
}

@Test
public void test() {

// 让浏览器访问 zTree Demo
driver.get("http://www.ztree.me/v3/demo/cn/core/async.html");

// 等待 zTree 初始化完毕，Timeout 设置10秒
try {
(new WebDriverWait(driver,
10, 500)).until(new ExpectedCondition<Boolean>() {

public Boolean apply(WebDriver d) {
WebElement element = (WebElement) ((JavascriptExecutor)driver).executeScript("return $('#treeDemo li').get(0);");

return element != null;

}
});

} catch(Exception e) {
e.printStackTrace();
}

((JavascriptExecutor)driver).executeScript("window.zTreeObj = $.fn.zTree.getZTreeObj('treeDemo');");

//判断节点总数
Long count =(Long) ((JavascriptExecutor)driver).executeScript("return window.zTreeObj.transformToArray(window.zTreeObj.getNodes()).length;");

assertTrue(count == 4);

//利用 expandNode 方法展开第一个父节点
((JavascriptExecutor)driver).executeScript("window.zTreeNode = window.zTreeObj.getNodeByParam('isParent', true); window.zTreeObj.expandNode(window.zTreeNode, true);");

try {
(new WebDriverWait(driver,
10, 500)).until(new ExpectedCondition<Boolean>() {

public Boolean apply(WebDriver d) {
Boolean isAjaxing = (Boolean) ((JavascriptExecutor)driver).executeScript("return !!window.zTreeNode.isAjaxing;");

return !isAjaxing;
}
});

} catch(Exception e) {
e.printStackTrace();
}
//判断节点总数
count =(Long) ((JavascriptExecutor)driver).executeScript("return window.zTreeObj.transformToArray(window.zTreeObj.getNodes()).length;");

assertTrue(count == 8);

//模拟 click 事件 单击节点 +/- 号展开
WebElement element = (WebElement) ((JavascriptExecutor)driver).executeScript("window.zTreeNode = window.zTreeNode.children[0]; return $('#' + window.zTreeNode.tId + '_switch').get(0);");

element.click();

// 展开第一个子节点
((JavascriptExecutor)driver).executeScript("window.zTreeObj.expandNode(window.zTreeNode, true);");

try {
(new WebDriverWait(driver,
10, 500)).until(new ExpectedCondition<Boolean>() {

public Boolean apply(WebDriver d) {
Boolean isAjaxing = (Boolean) ((JavascriptExecutor)driver).executeScript("return !!window.zTreeNode.isAjaxing;");

return !isAjaxing;
}
});

} catch(Exception e) {
e.printStackTrace();
}
//判断节点总数
count =(Long) ((JavascriptExecutor)driver).executeScript("return window.zTreeObj.transformToArray(window.zTreeObj.getNodes()).length;");

assertTrue(count == 12);

}

@AfterClass
public static
void destory() {
System.out.println("destory...");
//关闭浏览器
driver.quit();
}
}