CRUD + Hibernate + GWT

[matias casal]

Hello,

I am making a crud example with hibernate and gwt.
I made the following to delete and read:

 	public void deletePersona(String id) {
		String hql = "delete from Persona where id =" + id;
		Session session = HibernateUtil.getSessionFactory().getCurrentSession();
		session.beginTransaction();
		Query query = session.createQuery(hql);

		int rowCount = query.executeUpdate();
		System.out.println("Filas afectadas: " + rowCount);
		session.getTransaction().commit();
		getAccounts();
	
		

	}

	@Override
	public void addPersona(PersonaDTO personaDTO) {

	    Persona persona = new Persona(personaDTO);
	    Session session = HibernateUtil.getSessionFactory().getCurrentSession();
	    session.beginTransaction();
	    session.save(persona);
	    session.getTransaction().commit();
	   // return account.getId();
		   

They work perfectly, the information change on my mysql database, but the problem is that when I execute them the page/tables does not refresh automatically.

Does anyone knows how to make the dynamic update when the table is changed ?

Thank you!

[Maneesh Godbole]

The code you have posted is the server side code. To refresh the UI, you will need to write the update UI operations explicitly.
You can have these methods return the POJO which was affected and use that to refresh your UI.

[matias casal]

you will need to write the update UI operations explicitly

I did not make that.

Can you explain me shortly how to write the update UI operations ? Or give any tutorial about this ?

[Maneesh Godbole]

In pseudo code:
1) Initiate the server call from the UI, typically on a button click or some similar user action
2) The server call method is defined by you, so you can have whatever return types you want. In your case it can return the required POJO
3) Once you get the POJO back, you can modify your UI accordingly.

The steps and code required to do this cannot be posted here. Instead, check out the GWT site which has code samples and a detailed explanation.

[Maneesh Godbole]

You might also find this useful
http://code.google.com/webtoolkit/articles/using_gwt_with_hibernate.html

[matias casal]

I could not understand correctly.
My delete UI is something like this

  
public class BorrarUsuario extends Composite {
	String id = "0";
	
public BorrarUsuario(final MusicStoreServiceAsync musicStoreService) {

		final FlexTable ft = new FlexTable();
		ft.setText(1, 1, "ID");
		ft.setText(1, 2, "Nombre");

		musicStoreService.getAccounts(new AsyncCallback<List<PersonaDTO>>() {
			@Override
			public void onFailure(Throwable caught) {
				Window.alert("Error cargando a las personas: "
						+ caught.getMessage());
			}

			@Override
			public void onSuccess(List<PersonaDTO> result) {
				int i = 2;
				for (PersonaDTO personaDTO : result) {
					Button button = new Button("Borrar");
					ft.setText(i, 1, String.valueOf(personaDTO.getId()));
					ft.setText(i, 2, String.valueOf(personaDTO.getNombre()));

					ft.setWidget(i, 3, button);

					id = String.valueOf(personaDTO.getId());

					button.addClickHandler(new ClickHandler() {

						@Override
						public void onClick(ClickEvent event) {
							musicStoreService.deletePersona(id,
									new AsyncCallback<Void>() {
										public void onFailure(Throwable caught) {
											Window.alert("Error");
										}

										@Override
										public void onSuccess(Void result) {
											Window.alert("Persona borrada");
											
										}
									});

						}
					});

					i++;

				}

			}

		});
		this.initWidget(ft);
	}

}


  

What should I add to this to make it works ?

[Maneesh Godbole]

The code looks OK.
You get a list of POJOs and you update the flex table with the ID, name and a delete button.

You can store a copy of the account list as an instance variable. Populate it when your UI is built the first time.
When you add a new account, add the newly created POJO to this list and rebuild the UI.
When you delete an account, remove the POJO from this list and rebuild the UI.
For this you will need to remove all existing data using the appropriate remove methods, or better yet just create a new instance of the FlexTable and (re)populate it

[matias casal]

When you add a new account, add the newly created POJO to this list and rebuild the UI.
When you delete an account, remove the POJO from this list and rebuild the UI.

I have my different flextables in different classes that exteds composites.

Thats what I would like to know, how should I rebuild the UI ???

Thanks!

[Maneesh Godbole]

As per your code, after a successful async call, you are adding rows containing the data for id, number and the button. For every UI refresh, you can invoke FlextTable#removeAllRows and then use your existing code to populate it.

[Deepak Agarwal]

You should use 'Store' and 'Loader' to bind your data with grid, that way after successfully update you would just call load method on your loader and changes will be reflected immediately and with no extra coding.