How to validate empty Text Field?

Question

Hi,
I am Thirupathi,
I am new to JSF. I am able to validate the value of a component which has some value using attribute
validator="#{UserNumberBean.validate}"
in this case it is calling validate method of UserNumberBean.
but if i keep the field empty then it is not calling that validate method of UserNumberBean.
Please can any one clarify my doubt.
wait for reply
Thanx in advance.
Thirupathi Reddy
mail Id: [email protected]

Answer 1

validate method is called to validate the correctness of the value input by user (eg. email format, phone numebr etc.). If user leaves the input box empty then there is nothing to validate and so validate is not called.
If you want customised messages for required fields you can use requiredMessage attribute in your inputText tag provide that you are using JSF1.2. It is not available in JSF1.1. In JSF1.1 it is requires some extra coding. You can do like this :
In your managed bean
public class MyBean {
    private String userName = "";
    private String password = "";
    private ArrayList errors = new ArrayList();
    public String getErrors() {
        String message;
        if (errors.size() == 0) {
            message = "";
        } else {
            message = "<FONT COLOR=RED><UL>\n";
            for(int i=0; i<errors.size(); i++) {
                message = message + "<LI>" +
                        (String)errors.get(i) + "\n";
            message = message + "</UL></FONT>\n";
        return(message);
    public String validateUser() {
        errors.clear();
        if (userName  == null || userName.trim().length() == 0) {
            errors.add("User Name is required");
        if (password == null || password.trim().length() == 0) {
            errors.add("password is required");
        if (errors.size() > 0) {
            return(null);
        } else {
           //perform your logic here
           return("returnString");
}In your jsp page, include the errors tag as below. It will show all errors on top of the page.
<f:view>
        <h:form>
            <h:outputText value="#{MyBean.errors}" escape="false"/>
            <p>User Name: <h:inputText value="#{MyBean.userName}" /></p>
            <p>Password: <h:inputText value="#{UserBean.password}" /></p>
            <h:commandButton value="Login" action="#{UserBean.validateUser}" />
        </h:form>
    </f:view>One point to remember is to clear the errors List in every action.
Hope it helps.
-Hitesh