How to get HTML5 validation message with selenium?

Question

Please see this website.

After click log in i have this User credentials form and after try to login with missing Email Address or Password i g

Answer 1

The validation messages are not the part of your DOM. They are generated because your input fileds have required attribute. If you see the HTML of your fields -

You can see it has required attribute turned on. Check this out. You can verify that your fields have this required attribute or not, like this-

WebElement inputElement = driver.findElement(By.name("uname"));
JavascriptExecutor js = (JavascriptExecutor) driver;  
boolean isRequired = (Boolean) js.executeScript("return arguments[0].required;",inputElement)
if(isRequired )
{
   //element is required and validation error will popup if the field is empty.
}

There is no need to care about whether the message appears or not because that will handled by the browser.