Getting error org.openqa.selenium.JavascriptException: javascript error: Cannot read properties of n-CodePudding

I am automating a web page (using Selenium with Java) where I have to click on a button on the webpage. After clicking the button, a new window opens up and I am able to switch to the new window using Window handles. However, the new window consists of a data table, whose all entries are hidden in the form:

<tr >
    <td >
        <input type="hidden" name="createdBy[0]" value="TESTOR02"> 
        TESTOR02 
        <br> 
        <input type="hidden" name="createdTimestamp[0]" value="JAN 30, 2023"> 
        JAN 30, 2023 
    </td>
    <td valign="top" >
        <input type="hidden" name="text[0]" value="Test Agreement Text Six"> 
        Test Agreement Text Six 
    </td>
</tr>

Now, when I am searching this value in console using >> document.querySelector("tr:nth-child(2) > td:nth-child(2) > input[type=hidden]").value, I am getting the correct output. However, when I am running this through automation script >>

JavascriptExecutor js = (JavascriptExecutor) driver;
String text = (String) js.executeScript("document.querySelector('tbody > tr.tdtable_even_row > td:nth-child(2) > input').value");
System.out.println(text);

I am getting the error >> org.openqa.selenium.JavascriptException: javascript error: Cannot read properties of null (reading 'value')

Any inputs as to why automation is giving the error but browser console is giving correct output and how to fix this?

I tried to get the desire output through automation as is displayed in browser console, however error is being displayed in automation script

CodePudding user response：

Can you try this on your code

String text = (String) js.executeScript("return document.querySelector('tr.tdtable_even_row td:nth-child(2) input[type=hidden]').value");

CodePudding user response：

The error is occurring because the element you are trying to access is not found on the page. The selector you are using in the automation script, document.querySelector('tbody > tr.tdtable_even_row > td:nth-child(2) > input'), is not finding the desired hidden input element.

To fix this, you can try using a more specific selector to target the desired element, for example:

String text = (String) js.executeScript("return document.querySelector('input[name=\'text[0]\']').value");
System.out.println(text);

You can also try waiting for the element to be present on the page before accessing it, using WebDriverWait:

WebDriverWait wait = new WebDriverWait(driver, 10);
WebElement element = wait.until(ExpectedConditions.presenceOfElementLocated(By.cssSelector("input[name='text[0]']")));
String text = (String) js.executeScript("return arguments[0].value", element);
System.out.println(text);