Check if any alert exists using selenium with python

Question

I'm trying to write a test with selenium in python language for a web page that manages users. In this page someone can add role for users and if a role exists while adding it, an alert raises. I don't know if the alert is a javascript alert or an element of the web page. I want to automatically check the existence of the alert, because checking for the role in the list wastes time and has an enormous load. I tried this:

browser = webdriver.Firefox() browser.get("url") browser.find_the_element_by_id("add_button").click() try:     alert = browser.switch_to_alert()     alert.accept()     print "alert accepted" except:     print "no alert" 

But it didn't work and I got the "UnexpectedAlertPresentException". I also tried this:

browser = webdriver.Firefox() browser.get("url") browser.find_the_element_by_id("add_button").click() s = set(browser.window_handles) s.remove(browser.current_window_handle) browser.switch_to_window(s.pop())  

But I got the same exception. Additionally, I tried to access the alert with firebug to check if I can get access with its properties, but right click was disabled. I need a solution very quickly, even in other languages. I can understand the approach anyway. I will appreciate any help.

Answer 1

What I do is to set a conditional delay with WebDriverWait just before the point I expect to see the alert, then switch to it, like this:

from selenium import webdriver from selenium.webdriver.support.ui import WebDriverWait from selenium.webdriver.support import expected_conditions as EC from selenium.common.exceptions import TimeoutException  browser = webdriver.Firefox() browser.get("url") browser.find_element_by_id("add_button").click()  try:     WebDriverWait(browser, 3).until(EC.alert_is_present(),                                    'Timed out waiting for PA creation ' +                                    'confirmation popup to appear.')      alert = browser.switch_to.alert     alert.accept()     print("alert accepted") except TimeoutException:     print("no alert") 

WebDriverWait(browser,3) will wait for at least 3 seconds for a supported alert to appear.