如何处理-在缓存中找不到元素-自从在Selenium WebDriver Java测试中查找页面以来，页面可能已更改

Question

This is HTML code to display the delete icon on table and I need to click on symbol to delete the data from table but its id is changing for every table row dynamic therefore unable to use id in Selenium java code. I had used the className but it is also not working.

HTML

<a href="#">
    <img id="489" class="delete" width="16" height="16" title="Delete Project" alt="Delete Project" src="../media/internalnotforuse/images/icons/del.png"></img>
</a>

Code

if (projectName.equals("Test")) {
    System.out.println("Table Data : " + projectName);
    System.out.println("Table Row " + rowCount);

    rowCells.get(4).click(); // it is working fine
    webdriver.findElement(By.className("delete")).click();

    // webdriver.findElement(By.id("493")).click(); 
    //it is working fine but it hard coded 

    for(String winHandle : sWindowHandles){
        webdriver.switchTo().window(winHandle);
    }

    // confirm the confirmation from dialog option Yes/NO
    if(deleteConfirmaton == "Yes"){
        webdriver.findElement(By.xpath("//*[@id='deleteError_confirm']/table/tbody/tr[2]/td/input[1]")).click();

        //webdriver.findElement(By.xpath("//*[@id='projectList']/tbody/tr[76]/td[1]")).click();     
    }
    else{
        webdriver.findElement(By.xpath("//*[@id='deleteError_confirm']/table/tbody/tr[2]/td/input[2]")).click();
        System.out.println(" deleteConfirmaton is NO therefore would not be deleted " );
    }
}

Output

FAILED: projectDelete
org.openqa.selenium.StaleElementReferenceException: Element not found in the cache - perhaps the page has changed since it was looked up
Command duration or timeout: 20.07 seconds
For documentation on this error, please visit: http://seleniumhq.org/exceptions/stale_element_reference.html
Build info: version: '2.37.0', revision: 'a7c61cb', time: '2013-10-18 17:15:02'
System info: host: 'TSSGMSL058', ip: '10.56.40.179', os.name: 'Windows 7', os.arch: 'x86', os.version: '6.1', java.version: '1.7.0_51'
Session ID: 9a41792f-ea05-4904-ad03-6b80396e5ccd
Driver info: org.openqa.selenium.firefox.FirefoxDriver
Capabilities [{platform=XP, databaseEnabled=true, cssSelectorsEnabled=true, javascriptEnabled=true, acceptSslCerts=true, handlesAlerts=true, browserName=firefox, browserConnectionEnabled=true, nativeEvents=true, webStorageEnabled=true, rotatable=false, locationContextEnabled=true, applicationCacheEnabled=true, takesScreenshot=true, version=27.0.1}]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

Answer 1

StaleElementReferenceException indicates that since you found the element, the page source HTML has been refreshed by page load or JavaScript, and therefore may be stale. This is true even if our object can still be found in the newly refreshed HTML.

However, your case looks slightly strange as it doesn't appear to be caching any objects.

I am wondering if there are multiple elements with the same class, the first one of which quickly goes stale? Very unlikely but without seeing the entire stack trace with line numbers, it is hard to say.

However, you could try using a CSS selector such as;

By.Css("img.delete[id]")

This will extract all IMG with a class of delete and has id populated. You could go further;

By.Css("img.delete[id][src$='del.png']")

This adds a further check that the image src ends with del.png.

Can you try these or at least provide exact details of the line which erroring and the full stack trace?

Answer 2

Here is the solution friends, Just add an statement break; or continue; as a last statement in for loop according to your logic. It will remove the error and the code will work fine.I am modifying the code see below...

 if (projectName.equals("Test")) { System.out.println("Table Data : " + projectName); System.out.println("Table Row " + rowCount); rowCells.get(4).click(); // it is working fine webdriver.findElement(By.className("delete")).click(); // webdriver.findElement(By.id("493")).click(); //it is working fine but it hard coded for(String winHandle : sWindowHandles){ webdriver.switchTo().window(winHandle); break; //or continue; } // confirm the confirmation from dialog option Yes/NO if(deleteConfirmaton == "Yes"){ webdriver.findElement(By.xpath("//*[@id='deleteError_confirm']/table/tbody/tr[2]/td/input[1]")).click(); //webdriver.findElement(By.xpath("//*[@id='projectList']/tbody/tr[76]/td[1]")).click(); } else{ webdriver.findElement(By.xpath("//*[@id='deleteError_confirm']/table/tbody/tr[2]/td/input[2]")).click(); System.out.println(" deleteConfirmaton is NO therefore would not be deleted " ); } }