Alert Message When TextField is empty (javafx) - javafx

Question

I would like for my code to check if the textfields in my form are empty & then show a pop up alert message. My problem is, even if the textfields are filled in this alert message pops up as soon as I hit "ENTER" anyway. Any help is appreciated !
BtnEnter.setOnAction((ActionEvent e) -> {
if (txtfName.getText().isEmpty() | txtlName.getText().isEmpty() |
txtMI.getText().isEmpty() | txtStreeAdd.getText().isEmpty()
| txtCity.getText().isEmpty() | txtZip.getText().isEmpty()
| txtPhone.getText().isEmpty() | txtEmail.getText().isEmpty()
| txtSecEmail.getText().isEmpty()) {
Alert alert = new Alert(Alert.AlertType.WARNING);
alert.setTitle("Warning");
alert.setHeaderText("Required Fields Empty");
alert.setContentText("The fields highlighted in red must be filled "
+ "out.\nPlease try again.");
alert.showAndWait();

Answer 1

I believe part of the issue may be using the single pipe | for OR instead of the standard ||.
However, there's another approach you could take that may be a little easier to read. This is how I handle validation in my applications:
public boolean validate() {
StringBuilder errors = new StringBuilder();
// Confirm mandatory fields are filled out
if (txtfName.getText().trim().isEmpty()) {
errors.append("- Please enter a first name.\n");
}
if (txtlName.getText().trim().isEmpty()) {
errors.append("- Please enter a last name.\n");
}
if (txtMI.getText().trim().isEmpty()) {
errors.append("- Please enter a middle initial.\n");
}
if (txtStreetAdd.getText().trim().isEmpty()) {
errors.append("- Please enter a street address.\n");
}
if (txtCity.getText().trim().isEmpty()) {
errors.append("- Please enter a city.\n");
}
if (txtZip.getText().trim().isEmpty()) {
errors.append("- Please enter a ZIP code.\n");
}
if (txtPhone.getText().trim().isEmpty()) {
errors.append("- Please enter a phone number.\n");
}
if (txtEmail.getText().trim().isEmpty()) {
errors.append("- Please enter a primary email address.\n");
}
if (txtSecEmail.getText().trim().isEmpty()) {
errors.append("- Please enter a secondary email address.\n");
}
// If any missing information is found, show the error messages and return false
if (errors.length() > 0) {
Alert alert = new Alert(Alert.AlertType.WARNING);
alert.setTitle("Warning");
alert.setHeaderText("Required Fields Empty");
alert.setContentText(errors.toString());
alert.showAndWait();
return false;
}
// No errors
return true;
}
This has the added benefit of letting the user know exactly what information is missing as well. With this, you simply call the validate() method when the user clicks the action button. If validate() comes back true, you know you have all the information needed.

Answer 2

You can also approach it in this another way without Alert alert = new Alert(Alert.AlertType.WARNING); Here is a piece of code:
public boolean validateForm() {
StringBuilder errors = new StringBuilder();
// Confirm mandatory fields are filled out
if (jTextField1.getText().trim().isEmpty()) {
errors.append("- Please enter a first name.\n");
jTextField1.requestFocusInWindow();
JOptionPane.showMessageDialog(null, errors, "Warning!", JOptionPane.ERROR_MESSAGE);
return false;
}
if (jTextField2.getText().trim().isEmpty()) {
errors.append("- Please enter a last name.\n");
jTextField2.requestFocusInWindow();
JOptionPane.showMessageDialog(null, errors, "Warning!", JOptionPane.ERROR_MESSAGE);
return false;
}
String s = ((JTextField)jDateChooser1.getDateEditor().getUiComponent()).getText();
if (s.equals("")) {
errors.append("- Please choose a date.\n");
jDateChooser1.requestFocusInWindow();
JOptionPane.showMessageDialog(null, errors, "Warning!", JOptionPane.ERROR_MESSAGE);
return false;
}
if (jTextField3.getText().trim().isEmpty()) {
errors.append("- Please enter the age.\n");
jTextField3.requestFocusInWindow();
JOptionPane.showMessageDialog(null, errors, "Warning!", JOptionPane.ERROR_MESSAGE);
return false;
}
return true;
}
In this way, you can check if users know what exactly missing and show them an alert message. Add a listener for the button.
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
if(validateForm()) {
System.out.println("First name: "+jTextField1.getText());
System.out.println("Last name: "+jTextField2.getText());
System.out.println("Date: "+jDateChooser1.getDate());
System.out.println("Age: "+jTextField3.getText());
}
}