Shihab's Blog: 05

for last couple of days i was looking into jgoodies validation. but i found that it doesn't have enough quick start guide or simple sample code. the sample code provided with jgoodies are too complex. i have searched the net but i failed.
then i asked hasan's help. he said, "give me the complex code, i will simplify it". then i think, why don't i do that. so here is my simple code.

first assume you have a domain object as follow:

public interface User {
  public String getUserName();
  public void setUserName(final String pUserName);
  public String getPassword();
  public void setPassword(final String pPassword);
}

and it's implementation UserImpl.

you also have a form with two text fields mUserNameTextField and mPasswordField

now first create a Validator class

public class UserValidator extends AbstractValueModel
    implements Validator, User {
  private User mUser = new UserImpl();
  public Object getValue() {
    return this;
  }
  public void setValue(Object pObject) {
    // never used
  }
  public User getUser() {
    return mUser;
  }
  public void setUser(final User pUser) {
    mUser = pUser;
  }
  public ValidationResult validate() {
    ValidationResult result = new ValidationResult();
    if (ValidationUtils.isEmpty(mUser.getUserName())) {
      result.addError("User name is required");
    }
    if (ValidationUtils.isEmpty(mUser.getPassword())) {
      result.addError("Password is required");
    }
    return result;
  }
  public String getUserName() {
    return mUser.getUserName();
  }
  public void setUserName(final String pUserName) {
    mUser.setUserName(pUserName);
  }
  public String getPassword() {
    return mUser.getPassword();
  }
  public void setPassword(final String pPassword) {
    mUser.setPassword(pPassword);
  }
}

in the form class create there fields

private ValidationResultModel mValidationResultModel =
    new DefaultValidationResultModel();
private PresentationModel mPresentationModel =
    new PresentationModel(new UserValidator());
private JLabel mMessageLabel = ValidationResultViewFactory.
    createReportIconAndTextLabel(mValidationResultModel);

after initializing the form

Bindings.bind(userNameTextField,
    mPresentationModel.getBufferedModel("userName"));
Bindings.bind(passwordTextField,
    mPresentationModel.getBufferedModel("password"));

here "userName" and "password" are the properties of your domain class.

finally in the action handler for form submit

mPresentationModel.triggerCommit();
UserValidator validator =
    (UserValidator) mPresentationModel.getBean();
ValidationResult result = validator.validate();
mValidationResultModel.setResult(result);
if (result.isEmpty()) {
  // do your action handling here
}

isn't it very easy!!!