我有一个 GWT 单元树，用于显示来自 CMS 的文件结构。我正在使用AsyncDataProvider从我创建的自定义 RPC 类加载数据。我还有一个 Web Socket 系统，它将广播来自也在系统中工作的其他客户端的事件（文件创建、重命名、移动、删除等）。
我想要解决的是当我收到这些事件之一时，我如何正确更新我的细胞树？
我想这个问题类似于在页面上有两个我的 Cell Tree 实例，它们呈现相同的服务器端数据，并希望确保当用户更新一个时，另一个也更新，通过使用EventBus.
我觉得这应该很简单，但我现在已经花了大约 6 个小时，没有任何进展。我的代码包括在下面：
注意：我没有使用 RequestFactory，即使它看起来像是我的自定义 RPC 框架。此外， FileEntity 只是一个文件的简单表示，其名称可由getName().
private void drawTree() {
// fileService is injected earlier on and is my own custom rpc service
TreeViewModel model = new CustomTreeModel(new FileDataProvider(fileService));
CellTree tree = new CellTree(model, "Root");
tree.setAnimationEnabled(true);
getView().getWorkspace().add(tree);
}
private static class CustomTreeModel implements TreeViewModel {
// I am trying to use a single AsyncDataProvider so I have a single point of loading data which I can manipulate (Not sure if this is the correct way to go)
public CustomTreeModel(FileDataProvider dataProvider) {
this.provider = provider;
}
public <T> NodeInfo<?> getNodeInfo(final T value) {
if (!(value instanceof FileEntity)) {
// I already have the root File loaded in my presenter, if we are at the root of the tree, I just add it via a list here
ListDataProvider<FileEntity> dataProvider = new ListDataProvider<FileEntity>();
dataProvider.getList().add(TreeWorkspacePresenter.rootFolder);
return new DefaultNodeInfo<FileEntity>(dataProvider,
new FileCell());
} else {
// Otherwise I know that we are loading some tree child data, and I invoke the AsyncProvider to load it from the server
provider.setFocusFile(value);
return new DefaultNodeInfo<FileEntity>(provider,
new FileCell());
}
}
public boolean isLeaf(Object value) {
if(value == null || value instanceof Folder)
return false;
return true;
}
}
public class FileDataProvider extends AsyncDataProvider<FileEntity> {
private FileEntity focusFile;
private FileService service;
@Inject
public FileDataProvider(FileService service){
this.service = service;
}
public void setFocusFile(FileEntity focusFile){
this.focusFile = focusFile;
}
@Override
protected void onRangeChanged(HasData<FileEntity> display) {
service.getChildren(((Folder) focusFile),
new Reciever<List<FileEntity>>() {
@Override
public void onSuccess(List<FileEntity> files) {
updateRowData(0, files);
}
@Override
public void onFailure(Throwable error) {
Window.alert(error.toString());
}
});
}
}
/**
* The cell used to render Files.
*/
public static class FileCell extends AbstractCell<FileEntity> {
private FileEntity file;
public FileEntity getFile() {
return file;
}
@Override
public void render(Context context, FileEntity file, SafeHtmlBuilder sb) {
if (file != null) {
this.file = file;
sb.appendEscaped(file.getName());
}
}
}