Email validation in visualforce pages

Question

I have created a visualforce page where the chatter functionality will be given access to the external members of an organisation by entering an external agency email address. I have put validations to check the contents of the email field. For example if I have put email address as abc it throws an error as "enter email address in the correct format". But if I try to save the email address as blank space it gets saved and a blank space user is shown in the pending list of members.

Answer 1

For that also you need to keep a condition

say Suppose

var email = $(".email").val();
if(email=='' || email==null){
    alert("Enter a email Address");
    $(".email").focus();
    return false;
}

If u put a condition like that then it will throw a error message

Answer 2

If you are using apex:inputText component, you can use the "required" attribute to make it mandatory to a user to enter a value.

Answer 3

If you are using apex input text you can use the below apex code using regular expressions

public static boolean isUserEmailValid(String userEmail) {
        Boolean flag = false;
        if(userEmail != null) {
            String  emailRegex      = '([a-zA-Z0-9_\\-\\.]+)@((\\[a-z]{1,3}\\.[a-z]{1,3}\\.[a-z]{1,3}\\.)|(([a-zA-Z0-9\\-]+\\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})';
            Pattern emailPattern    = Pattern.compile(emailRegex);
            Matcher emailMatcher    = emailPattern.matcher(userEmail.trim());
            flag                    =  emailMatcher.matches();
        }
        return flag;
    }