Programmatically Update Gwt CellTree

Question

I want to fire the open root node event on my current working CellTree, which now has the following behavior:

@Override public <T> NodeInfo<?> getNodeInfo(final T value) { return new DefaultNodeInfo<Categoria>( (value instanceof Categoria) ? createBranchDataProvider((Categoria)value) : rootDataProvider, new CategoriaCell() ); } private AsyncDataProvider<Categoria> createRootDataProvider() { AsyncDataProvider<Categoria> dataProvider = new AsyncDataProvider<Categoria>() { @Override protected void onRangeChanged(HasData<Categoria> display) { AsyncCallback<Categoria[]> cb = new AsyncCallback<Categoria[]>() { @Override public void onSuccess(Categoria[] result) { updateRowCount(result.length, true); updateRowData(0, Arrays.asList(result)); } @Override public void onFailure(Throwable caught) { Window.alert(caught.toString()); } }; rpcService.getCategorie(cb); } }; return dataProvider; } 

How can I fire this onRangeChanged event to update my level 1 nodes?

What is my convenience method missing?

 private void updateTree() { TreeNode rootTreeNode = cellTree.getRootTreeNode(); for (int i = 0; i < rootTreeNode.getChildCount(); i++) { rootTreeNode.setChildOpen(i, false); } // HOW TO REFRESH LEVEL-1 NODES? } 

Answer 1

Level 1 nodes (I assume you are below the middle root of a node) cannot be updated the way you do it.

You must store an instance of your dataProvider for level 1 nodes somewhere. Later, when you update your list, you must update your saved dataProvider for your level 1 nodes.

Nodes below level 1 can be updated as you do. Because, as soon as you close the nodes of level 1 (this is what you do in the updateTree method), and the next time you open it, getNodeInfo will be called, and the updated subcategories will be extracted and displayed in CellTree.

UPDATE

To update CellWidgets connected to AsyncDataProvider, you probably have to extend AsyncDataProvider and either retrieve the RPC call to getData () , which is called in the onRangeChanged () method, or creates an interface using the update method and implements it in your custom AsyncDataProvider, which calls protected onRangeChanged () method.

Answer 2

Working example. Add a link to the DataProvider (and the parent Node) (MyMenuItem and MyCell with the DataProvider in my code). After you add the parent item, the item updates.

 public class MyMenuItem { private String name; private String action; //some data private int level; //if needed private ArrayList<MyMenuItem> list; //nodes childrens private MyMenuItem parent; //track internal parent private MyCell cell; //for refresh - reference to visual component public void setCell(MyCell cell) { this.cell = cell; } public void refresh() { if(parent!=null) { parent.refresh(); } if (cell!=null) { cell.refresh(); //refresh tree } } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAction() { return action; } public void setAction(String action) { this.action = action; } public MyMenuItem(String name, String action) { super(); parent = null; level = 0; this.name = name; this.action = action; list = new ArrayList<MyMenuItem>(); } public MyMenuItem(String name) { this(name, ""); } public void addSubMenu(MyMenuItem m) { m.level = this.level+1; m.parent = this; list.add(m); } public boolean hasChildrens() { return list.size()>0; } public int getLevel() { return level; } public void setLevel(int level) { this.level = level; } public ArrayList<MyMenuItem> getList() { return list; } public MyMenuItem getParent() { return parent; } } public class MyTreeModel implements TreeViewModel { private MyMenuItem officialRoot; //default not dynamic private MyMenuItem studentRoot; //default not dynamic private MyMenuItem testRoot; //default not dynamic private MyMenuItem root; public MyMenuItem getRoot() { // to set CellTree root return root; } public MyTreeModel() { root = new MyMenuItem("root"); // Default items officialRoot = new MyMenuItem("Official"); //some basic static data studentRoot = new MyMenuItem("Student"); testRoot = new MyMenuItem("Test"); root.addSubMenu(officialRoot); root.addSubMenu(studentRoot); root.addSubMenu(testRoot); } //example of add add logic private void addNew(MyMenuItem myparent, String name, String uid) { myparent.addSubMenu(new MyMenuItem(name, uid)); myparent.refresh(); //HERE refresh tree } @Override public <T> NodeInfo<?> getNodeInfo(T value) { ListDataProvider<MyMenuItem> dataProvider; MyMenuItem myValue = null; if (value == null) { // root is not set dataProvider = new ListDataProvider<MyMenuItem>(root.getList()); } else { myValue = (MyMenuItem) value; dataProvider = new ListDataProvider<MyMenuItem>(myValue.getList()); } MyCell cell = new MyCell(dataProvider); //HERE Add reference if (myValue != null) myValue.setCell(cell); return new DefaultNodeInfo<MyMenuItem>(dataProvider, cell); } @Override public boolean isLeaf(Object value) { if (value instanceof MyMenuItem) { MyMenuItem t = (MyMenuItem) value; if (!t.hasChildrens()) return true; return false; } return false; } } public class MyCell extends AbstractCell<MyMenuItem> { ListDataProvider<MyMenuItem> dataProvider; //for refresh public MyCell(ListDataProvider<MyMenuItem> dataProvider) { super("keydown","dblclick"); this.dataProvider = dataProvider; } public void refresh() { dataProvider.refresh(); } @Override public void onBrowserEvent(Context context, Element parent, MyMenuItem value, NativeEvent event, ValueUpdater<MyMenuItem> valueUpdater) { if (value == null) { return; } super.onBrowserEvent(context, parent, value, event, valueUpdater); if ("click".equals(event.getType())) { this.onEnterKeyDown(context, parent, value, event, valueUpdater); } if ("dblclick".equals(event.getType())) { this.onEnterKeyDown(context, parent, value, event, valueUpdater); } } @Override public void render(Context context, MyMenuItem value, SafeHtmlBuilder sb) { if (value == null) { return; } sb.appendEscaped(value.getName()); //add HERE for better formating } @Override protected void onEnterKeyDown(Context context, Element parent, MyMenuItem value, NativeEvent event, ValueUpdater<MyMenuItem> valueUpdater) { Window.alert("You clicked "+event.getType()+" " + value.getName()); } } 

in add module

  treeModel = new MyTreeModel(); tree = new CellTree(treeModel,treeModel.getRoot());