Selenium NoAlertPresentException - selenium

Question

I'm trying to handle dialog (Ok Cancel type) with selenium WebDriver. So my aim is to click "Ok" button.
Scenario is:
Click button for invoking dialog
button.click();
Try to accept
webDriver.switchTo().alert().accept();
But I'm always getting NoAlertPresentException and seeing that dialog closes almost immediately.
It seems to me that Selenium automatically closes dialog and when I want to accept, there is nothing to accept.
I'm sorry for my bad English.

Answer 1

The usual cause of this issue is that Selenium is too quick and tries to accept an alert that has not yet been opened by the browser. This can be simply fixed by an explicit wait:
button.click();
WebDriverWait wait = new WebDriverWait(driver, 5);
Alert alert = wait.until(ExpectedConditions.alertIsPresent());
alert.accept();

Answer 2

Step 1:
public boolean isAlertPresent(){
boolean foundAlert = false;
WebDriverWait wait = new WebDriverWait(driver, 0 /*timeout in seconds*/);
try {
wait.until(ExpectedConditions.alertIsPresent());
foundAlert = true;
System.out.println("isAlertPresent : " +foundAlert);
} catch (TimeoutException eTO) {
foundAlert = false;
System.out.println("isAlertPresent : " +foundAlert);
}
return foundAlert;
}
Step 2:
public boolean tocheck_POP_Dialog()
{ Alert alert;
try
{
alert=driver.switchTo().alert();
}
catch(NoSuchElementException elementException)
{
return false;
}
alert.accept(); //Close Alert popup
return true;
}
Step 3 :
if(dummyPage.isAlertPresent())
{
dummyPage.tocheck_POP_Dialog();
}

Answer 3

public boolean isAlertPresent(){
try{
Alert a = new WebDriverWait(driver, 10).until(ExpectedConditions.alertIsPresent());
if(a!=null){
System.out.println("Alert is present");
driver.switchTo().alert().accept();
return true;
}else{
throw new Throwable();
}
}
catch (Throwable e) {
System.err.println("Alert isn't present!!");
return false;
}
}
Use explicit wait to check the alert and then do the operation. This might help you. :)

Answer 4

Generally it happens because Selenium commands run too quick and it tries to close the alert before it is open. Hence, adding a delay after click event should resolve the issue. Also, if you are using Safari browser for your test, there is some issue with SafariDriver in handling alerts. SafariDriver cannot handle alerts should provide you more details.

Answer 5

Some additional info. for future readers of this thread:
If this exception persists even after the wait aspect is addressed, please check if the following sequence of steps is effective in the test script:
the underlying Html page's DOM is queried/parsed for some purpose (e.g. to look for Form errors)
(before the) driver.switch_to.alert is attempted
When an Alert is shown over an Html page, if the Alert is overlooked and the DOM underlying the Html page is queried first, the Webdriver appears to loose track of the Alert & causes the Exception.
This was observed with: geckodriver 0.21.0, Firefox 66.0b10 (64-bit) ; python 3.6.1 Selenium driver 3.14 (for Python).
Performing (2) before (1) was found to resolve the issue.