How to search for element in dynamic loading grid on scroll using selenium webdriver?

Question

There is Grid which has say 1000 rows with a column named Username(with distinct values).

And the grid will display only 20 rows per view, and the other rows will be loaded(ajax) only on scrolling.

So, how to search for a particular username in the grid, since we have only elements getting loaded on scroll.

Does Scrollintoview method help? Or do i need to use window.scrollby() until i find the searched item?

Answer 1

First of all, I apologise because I had never worked on a grid before. I thought it will be a frame and will be easier to switch and then scroll to the element using JavascriptExecutor. But, alas! That's not the case for a grid.
And, there must be a table when a grid is involved.

Now, this is what has worked for me.

First click on any visible element on grid to get it into focus.

Then scroll the grid using grid's locator(xpath,id,etc.) using 'Keys.PAGE_DOWN' till you find the element you are looking for.

In case the element is not found on each scrolls, than handle the exception it raises and scroll again.

Note: Do not forget to give some sleep time after each scroll.

I have automated one sample grid, and have attached the sample working code below. Hope this helps in figuring out problem:

import java.io.IOException;

import org.openqa.selenium.By;
import org.openqa.selenium.JavascriptExecutor;
import org.openqa.selenium.Keys;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;

public class ScrollGrid{

    public static void main(String[] args) throws IOException, InterruptedException{


        WebDriver driver = new FirefoxDriver();
        driver.get("https://demos.devexpress.com/ASPxGridViewDemos/PagingAndScrolling/VirtualPaging.aspx");
        driver.manage().window().maximize();

        //Clicking on an element inside grid to get it into focus
        driver.findElement(By.xpath("//*[@id='ContentHolder_ASPxGridView1_DXMainTable']//td[.='9/30/1994']")).click();

        WebElement ele=null;
        int flag=0;
        int count=0;

        do{
            try{
                //element to search for while scrolling in grid
                ele = driver.findElement(By.xpath("//*[@id='ContentHolder_ASPxGridView1_DXMainTable']//td[.='3/28/1996']"));
                flag=1;
            } catch(Throwable e){
                //scrolling the grid using the grid's xpath
                driver.findElement(By.xpath("//*[@id='ContentHolder_ASPxGridView1']//div[2]")).sendKeys(Keys.PAGE_DOWN);
                Thread.sleep(3000);
            }
        }while((flag==0) || ((++count)==250));

        if(flag==1){
            System.out.println("Element has been found.!!");
        }else{
            System.out.println("Element has not been found.!!");
        }

        highlightElement(driver, ele); //For highlighting the element
        Thread.sleep(5000L); //to check if the element scrolled to is highlighted.
        driver.close();
    }

    //For highlighting the element to be located after scroll
    public static void highlightElement(WebDriver driver, WebElement ele) {
        try
        {
            for (int i = 0; i < 3; i++) 
            {
                JavascriptExecutor js = (JavascriptExecutor) driver;
                js.executeScript("arguments[0].setAttribute('style', arguments[1]);",ele, "color: red; border: 2px solid red;");
            }
        }
        catch(Throwable t)
        {
            System.err.println("Error came : " +t.getMessage());
        }
    }

}

Note: This works correctly now. It will come out of the loop in case the element is found, or if not found after 250 scrolls. '250' is a relative number. You can change it to the number of scrolls you want to perform on the grid.