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The wait.until returns stale element, how to wait until DOM is stable

I have a blazor application running fine and want to have some behavior test with selenium. The test does now currently the following:
goes to a page (directly using an URL, no page loaded before)
tries to click on a button
The first point does work, but the second has an issue. If I use the wait.until the button is available, then I receive back an early version of the button, which then redrawn and updated in the DOM later. This will give me the "stale element reference: element is not attached to the page document" error.
Here is the code:
var xPath = By.XPath($".//tr//td[normalize-space()=\"{name}\"]/ancestor-or-self::tr//button");
var button = _wait.Until(ExpectedConditions.ElementToBeClickable(xPath));
Thread.Sleep(1000);
button = _chromeDriver.FindElement(xPath);
button.Click();
the _wait.until will return an item that will be stale, while the next FindElement will return a valid, but only after ~1 sec sleep. If I don't have sleep there, it will return the same as the other line.
The final question: How can I ensure in the _wait.until line, that my returned element is the final one to avoid using Thread.Sleep?

There is no gentle solution for such issues.
The only solution I know for this is to make a loop:
Wait for element clickability and click it.
In case exception is thrown wait for the clickability again.
If click succed - break the loop and continue to outer code / return True.
Something like this:
for(i=0; i<6; i++){
try: {
wait.Until(ExpectedConditions.ElementToBeClickable(xPath)).Click();
break;
}
catch(Exception e){
Thread.Sleep(100);
}
}

#golddragon007, you can wait for the element to become stale.
_wait.Until(ExpectedConditions.StalenessOf(_chromeDriver.FindElement(xPath)))
you can check the following link for more details:
https://www.selenium.dev/selenium/docs/api/dotnet/html/M_OpenQA_Selenium_Support_UI_ExpectedConditions_StalenessOf.htm

Selenium Wait.Until conditions are not 100% reliable. I was in shock when I figureג this myself, but yes, after the condition has finished you sometimes have to wait or try clicking or hovering in a loop.
I wish to suggest 2 options here:
Wait for the element to be both Clickable and Enabled:
getWait().until((ExpectedCondition) driver -> element.isEnabled());
Use a much better UI tool for testing like Playwright. It has a much sophisticated waiting system conditions and is also faster and very reliable.

Prophet's answer is a good approach, so have a look at that. Sometimes you just need to try something more than one time. This is an alternative that is easier to reuse and more flexible.
All of the methods on the WebDriverWait class expect a lambda express to return a value. Sometimes I need to call a method with a void return type, so I write an extension method on WebDriverWait to support this:
public static class WebDriverWaitExtensions
{
public static void Until(this WebDriverWait wait, Action<IWebDriver> action)
{
wait.Until(driver =>
{
action(driver);
return true;
});
}
}
This is much more flexible and easier to call with your code. This will attempt to click the element until it succeeds. A word of caution, however. The StaleElementException will cancel a wait operation immediately. Be sure to ignore this kind of exception.
var xPath = By.XPath($".//tr//td[normalize-space()=\"{name}\"]/ancestor-or-self::tr//button");
_wait.IgnoredExceptionTypes(typeof(StaleElementException));
_wait.Until(driver => driver.FindElement(xpath).Click());
This should work with any web driver method that has a void return type.

It seems another solution is this:
_wait.Until(driver => (bool)((IJavaScriptExecutor)driver).ExecuteScript("return typeof Blazor.reconnect != 'undefined'"));
as that variable only loaded when the page is fully loaded. And after that it's possible to do a simple find without an issue:
var button = _chromeDriver.FindElement(xPath);

Implement polly as your resilience framework for Selenium methods you create an example you can see below:
public static IWebElement Click(string xPath, int retries = 15,
int retryInterval = 1)
{
var element = Policy.HandleResult<IWebElement>(result => result == null)
.WaitAndRetry(retries, interval => TimeSpan.FromSeconds(retryInterval))
.Execute(() =>
{
var element = Searchers.FindWebElementByXPath(xPath);
if (element != null)
{
_logger.Info("Clicked Element: " + xPath + " (" + element.Text + ")");
try
{
_driver.ExecuteScript("arguments[0].click();", element);
return element;
}
catch (Exception e)
{
if (e is ElementClickInterceptedException or StaleElementReferenceException)
return null;
}
}
return null;
});
if (element != null) return element;
_logger.Info("Failed to click Element: " + xPath + "");
throw new Exception(" Failed to use Javascript to click element with XPath: " + xPath + "");
}
By leveraging the power of polly, I can guarantee that all of my events will go through.
Do not use the base Selenium methods to wait for certain properties to change/be a certain value, they are not very reliable.

Selenium stale element exception (found when running tests and not while debugging)

I am getting stale element exception when I run the code. However while debugging I do not get this exception.
Here is my piece of code. Can anybody help me ? thanks
public static bool CheckListFilterResult(IList<IWebElement> gridColumns, IList<IWebElement> gridRows, string filterColumn, List<string> filters)
{
bool checkResult = false;
{
int filterColumnIndex = GetColumnIndex(gridColumns, filterColumn);
if (gridRows.Count > 0 )
{
foreach (IWebElement row in gridRows)
{
TestManager.Doc.Step("before bool match");
bool filterMatch = filters.Contains(row.FindElements(By.TagName("td"))[filterColumnIndex].Text.Trim());
if (filterMatch)
{
checkResult = true;
}
else
{
checkResult = false;
break;
}
}
}
}
return checkResult;
}
}

From looking at your code, that line is the first line where you access something from the rows collection. My guess is that it has something to do with that. Did you pull the rows collection, then apply a filter, then call this function? If so, that's probably the problem. You need to apply the filter, then pull the rows collection, then call the function.

It could be that your IWebElement row was updated by javascript while you were running your selenium code.
As explained here: http://docs.seleniumhq.org/exceptions/stale_element_reference.jsp, Stale Element Reference Exception happens when the object on the UI may have been refreshed but you are trying to access the same object. So even if the row is visible to the user, it may have been updated/replaced by javascript, then it is a different object.
The reason why it happens only occassionaly but not always could be that when you run in debug mode, you are stopping at each line of your selenium code, but javascript code doesnt stop, so the element on the UI was already refreshed, then your selenium code gets a fresh copy of the IWebElement row.
There are several possible ways of fixing this problem.
try to catch StaleElementReferenceException, if it happens, then redo whatever you are trying to do.
you can do: wait.until(ExpectedConditions.stalenessOf(row));
Hope it helps

Multi-threaded C# Selenium WebDriver automation with Uris not known beforehand

I need to perform some simultaneous webdrivers manipulation, but I am uncertain as to how to do this.
What I am asking here is:
What is the correct way to achieve this ?
What is the reason for the exception I am getting (revealed below)
After some research I ended up with:
1. The way I see people doing this (and the one I ended up using after playing with the API, before searching) is to loop over the window handles my WebDriver has at hand, and perform a switch to and out of the window handle I want to process, closing it when I am finished.
2. Selenium Grid does not seem like an option fore me - am I wrong or it is intended for parallel processing ? Since am running everything in a single computer, it will be of no use for me.
In trying the 1st option, I have the following scenario (a code sample is available below, I skipped stuff that is not relevant/repeat itself (where ever I added 3 dots:
I have a html page, with several submit buttons, stacked.
Clicking each of them will open a new browser/tab (interestingly enough, using ChromeDriver opens tabs, while FirefoxDriver opens separate windows for each.)
As a side note: I can't determine the uris of each submit beforehand (they must be determined by javascript, and at this point, let's just assume I want to handle everything knowing nothing about the client code.
Now, after looping over all the submit buttons, and issuing webElement.Click() on the corresponding elements, the tabs/windows open. The code flows to create a list of tasks to be executed, one for each new tab/window.
The problem is: since all tasks all depend upon the same instance of webdriver to switch to the window handles, seems I will need to add resource sharing locks/control. I am uncertain as whether I am correct, since I saw no mention of locks/resource access control in searching for multi-threaded web driver examples.
On the other hand, if I am able to determine the tabs/windows uris beforehand, I would be able to skip all the automation steps needed to reach this point, and then creating a webDriver instance for each thread, via Navigate().GoToUrl() would be straightforward. But this looks like a deadlock! I don't see webDriver's API providing any access to the newly opened tab/window without performing a switch. And I only want to switch if I do not have to repeat all the automation steps that lead me to the current window !
...
In any case, I keep getting the exception:
Element belongs to a different frame than the current one - switch to its containing frame to use it
at
IWebElement element = cell.FindElement
inside the ToDictionary() block.
I obviously checked that all my selectors are returning results, in chrome's console.
foreach (WebElement resultSet in resultSets)
resultSet.Click();
foreach(string windowHandle in webDriver.WindowHandles.Skip(1))
{
dataCollectionTasks.Add(Task.Factory.StartNew<List<DataTable>>(obj =>
{
List<DataTable> collectedData = new List<DataTable>();
string window = obj as string;
if (window != null)
{
webDriver.SwitchTo().Window(windowHandle);
List<WebElement> dataSets = webDriver.FindElements(By.JQuerySelector(utils.GetAppSetting("selectors.ResultSetData"))).ToList();
DataTable data = null;
for (int i = 0; i < dataSets.Count; i += 2)
{
data = new DataTable();
data.Columns.Add("Col1", typeof(string));
data.Columns.Add("Col2", typeof(string));
data.Columns.Add("Col3", typeof(string));
///...
//data set header
if (i % 2 != 0)
{
IWebElement headerElement = dataSets[i].FindElement(OpenQA.Selenium.By.CssSelector(utils.GetAppSetting("selectors.ResultSetDataHeader")));
data.TableName = string.Join(" ", headerElement.Text.Split().Take(3));
}
//data set records
else
{
Dictionary<string, string> cells = dataSets[i]
.FindElements(OpenQA.Selenium.By.CssSelector(utils.GetAppSetting("selectors.ResultSetDataCell")))
.ToDictionary(
cell =>
{
IWebElement element = cell.FindElement(OpenQA.Selenium.By.CssSelector(utils.GetAppSetting("selectors.ResultSetDataHeaderColumn")));
return element == null ? string.Empty : element.Text;
},
cell =>
{
return cell == null ? string.Empty : cell.Text;
});
string col1Value, col2Value, col3Value; //...
cells.TryGetValue("Col1", out col1Value);
cells.TryGetValue("Col2", out col2Value);
cells.TryGetValue("Col3", out col3Value);
//...
data.Rows.Add(col1Value, col2Value, col3Value /*...*/);
}
}
collectedData.Add(data);
}
webDriver.SwitchTo().Window(mainWindow);
webDriver.Close();
return collectedData;
}, windowHandle));
} //foreach
Task.WaitAll(dataCollectionTasks.ToArray());
foreach (Task<List<DataTable>> dataCollectionTask in dataCollectionTasks)
{
results.AddRange(dataCollectionTask.Result);
}
return results;

Waiting for all actions to be executed after clicking a button in selenium

i'm sorry if it's been answered before but i really couldn't find a good solution to my problem
I have an email input field and i want to check that when you input an invalid email an error message appears.
my code looks somthing like this:
private void LoadElements()
{
Email = driver.FindElement(By.Id("MainContent_Email"));
SaveButton = driver.FindElement(By.Id("MainContent_SaveButton"));
ErrorMessage = driver.FindElement(By.Id("MainContent_PersDetsError"));
}
public void test()
{
//Email, SaveButton & Error are IWebElement
LoadElements();
Email.Clear();
Email.SendKeys(emailString);
SaveButton.Click();
// Avoid stale element exception on refresh after a successful save:
LoadElements();
Assert.IsTrue(ErrorMessage.Displayed);
}
My problem is that when i try to purposly fail the test (input a valid email), some of the time I still get a stale element exception. I presume this happens becuse LoadElements() loads the web elements too quickly.
My question is this: is there a way to wait for the page to fully load before executing any commends?
PS I tried the following code and it didn't work for me
IWait<IWebDriver> wait = new OpenQA.Selenium.Support.UI.WebDriverWait(driver, TimeSpan.FromSeconds(30.00));
wait.Until(driver1 => ((IJavaScriptExecutor)driver).ExecuteScript("return document.readyState").Equals("complete"));

Stuck on implementation of WebBrowser Control and working with AJAX responses

Here we go...
I am trying to create a bot to walk through various functions of a website I do not have control of. Initially, I thought it would be best to just connect to the database (MySql) that the site is tied to and make my associations there...The database is built so extensively that I can't make out where to point what to where how etc...It's beyond my (DBA)programmer casting... ;)
So, my next idea was, create a bot...simple enough right? First hurdle, not everything on the page carries an ID...bring on the loops...
Got it.
Now I'm stuck with working with my data and page response.
I'm trying to fill out part of a form and perform an AJAX search. The problem is, there is no DocumentCompleted for this. And honestly, that isn't where my problem lies. I've tried using Thread.Sleep, Timers, etc...no avail.
// The app reads categories from a csv file,
// then performs a search for the category
// Search results are only displayed if I break the foreach loop
foreach (var item in bar)
{
var document = wbBrowser.Document;
if (document != null)
{
var name = document.GetElementById("product_filter_name");
if (name != null)
{
name.SetAttribute("value", item.Key.ToString());
var buttons = document.GetElementsByTagName("button");
foreach (HtmlElement button in buttons)
{
var findSearch = button.InnerHtml.IndexOf("Search");
if (findSearch > -1)
{
button.InvokeMember("click");
}
}
}
// This where the problem starts...
// I want the AJAX to run, then perform Step two,
// but the WebBrowser doesn't return the search
// results until the end (break;)
// Step Two
var elems = document.GetElementsByTagName("tr");
foreach (HtmlElement elem in elems)
{
// find particular item in result table
}
break;
// Now the search results display!!!!
// I tried implementing a timer, Thread.Sleep,
// everything I could find via Google before
//starting Step Two, but it hasn't worked!
}
}

The actual browser control has a WebBrowser.OnDocumentCompleted event which you might need to hook into so that you can be alerted when the ajax call has returned back from the server.