Create custom locators to find element in WebDriver Java

In order to make our web application under test more testable, we approached dev and asked them to assign a custom attribute (say data-id to all the web components).  The advantage of this approach is that, dev are now free to change any other attribute ( not data -id) as per the business requirement without breaking our UI automation tests.

Since data-id is a custom attribute that means, we have to use either By.xpath or By.Css and pass this data-id attribute every time.

Or Just imagine an application that has a lot of images with common attribute href. 

To efficiently tackle this situation, we can create our own custom locatory strategy by extending it from By Class.

To give an example :-

import java.util.List;

import org.openqa.selenium.By;
import org.openqa.selenium.SearchContext;
import org.openqa.selenium.WebElement;

public class ByImageSrc extends By 
{
    private final String imageByString;
    public ByImageSrc(String imageByString)
    {
        this.imageByString = imageByString;
    }

    @Override
    public List<WebElement> findElements(SearchContext context) 
    {
         List<WebElement> mockElements = context.findElements(By.xpath("//img[@src='" + imageByString + "']"));
         return mockElements;
    }
}

To use this in POM class, 

WebElement element = driver.findElement(new ByImageSrc("/path/to/image"));