我有一个GWT单元格树,我用它来显示CMS的文件结构。我正在使用从我创建的自定义RPC类加载数据的AsyncDataProvider
。我也有一个网络套接字系统,可以从系统中的其他客户端广播事件(文件创建,重命名,移动,删除等)。如何通过事件总线告诉GWT单元格小部件数据已更改?
我试图包裹我的头是当我收到这些事件之一,我如何正确更新我的细胞树?
我想这个问题可能类似于我的单元格树的两个实例在页面上,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,另一个更新时,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,没有进展。我的代码包括如下:
注意:即使它看起来像我是我的自定义RPC框架,我没有使用RequestFactory。此外,FileEntity只是一个文件的简单表示,其名称可由getName()
访问。
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());
}
}
}
不是我正在寻找的东西,但这是有效的。对于维护索引FileEntity-> TreeNode以改善查找时间,您有什么想法?谢谢! – 2013-02-27 19:05:19
是的,它总是更好地使用索引... – Adarsha 2013-02-28 03:13:40