Thymeleaf: how to use each but show default if no items are in list?

Question

I want to show a form that has a pre-filled list of objects and each of the object attributes as a field, retrieved from my database using Thymeleaf templates (that the user will then be able to edit). I understand I would use th:each to accomplish looping over each object in the returned list and creating the pre-filled form fields.

However, if there are no items retrieved from the database, I want to still show a form corresponding to that objects attributes, only with the pre-filled values empty. How would I implement this? I cannot find details in the documentation.

Answer 1

I am assuming you are doing something like this in your controller:

@GetMapping
public String showListOfObjectsForm(Model model) {
  List<MyObject> listOfObjects = service.get...
  model.addAttribute( "myList", listOfObjects );

  return "form"
}

You could check the size of listOfObjects and add a "dummy" object in the list:

@GetMapping
public String showListOfObjectsForm(Model model) {
  List<MyObject> listOfObjects = service.get...
  if( listOfObjects.isEmpty() ) {
    listOfObjects.add( new MyObject() );
  } 

  model.addAttribute( "myList", listOfObjects );
  
  return "form"
}