推送后如何更新Vaadin Grid? [英] How to update Vaadin Grid after push?

问题描述

从其他UI实例对网格进行更改后，我试图在Vaadin中更新网格.

I'm trying to update a grid in Vaadin after a change has been made to the grid from a different UI instance.

为了详细说明，我有两个不同的UI实例，UI1和UI2(来自两个不同浏览器的选项卡).这些UI实例包含一个视图，该视图包含一个由Contact对象组成的网格，这些对象具有各种属性，例如姓名，年龄，性别...

To elaborate, I have two different UI instances, UI1 and UI2 (tabs from two different browsers). These UI instances contain a view which contains a grid consisted of Contact objects that have various properties such as name, age, gender...

我从UI1向网格中添加了一个联系人，我希望UI2可以立即查看更新后的网格而无需刷新.

I add a Contact to the grid from UI1 and I want UI2 to see the updated grid instantly without having to refresh.

要做到这一点，我知道我必须使用已经使用Broadcaster类设置的Vaadin Push.我的UI类中有一个receiveBroadcast()方法，每当View类使用broadcast()方法向UI发送广播时，该方法都会更新UI.我的UI类的一部分看起来像这样:

To accomplish that, I know I have to use Vaadin Push which I already set up using a Broadcaster class. I have a receiveBroadcast() method in my UI class which will update the UI whenever a View class sends a broadcast to UIs using broadcast() method. Part of my UI class looks like this:

@Title("Contact Book")
@Theme("reindeer")
@Push
public class UserInterface extends UI implements BroadcastListener{    

    private Navigator navigator;

    @Override
    protected void init(VaadinRequest request){
        navigator = new Navigator(this, this);
        navigator.addView(ContactBookView.NAME, new ContactBookView());

        Broadcaster.register(this);
    }
    @Override
    public void detach(){
        Broadcaster.unregister(this);
        super.detach();
    }

    @Override
    public void receiveBroadcast(Grid grid) {
        access(()->{

            // update grid here
            Notification.show("Grid updated", Notification.Type.TRAY_NOTIFICATION);
        });
    }
}

我的Broadcaster类与此相同链接(我只是稍微改变了方法，以便可以将网格作为参数传递)

And my Broadcaster class is as the same in this link (I just altered the methods a bit so I can pass the grid as a parameter)

然后在我的ContactBookView类中，添加或更改项目后调用Broadcaster.broadcast(grid)方法，以便可以以某种方式在UI类的access()方法中更新网格，但是我尝试过的任何方法似乎均不起作用.我知道推送有效，因为收到广播后，我可以在所有UI实例中看到网格已更新"消息.

Then in my ContactBookView class I call Broadcaster.broadcast(grid) method after adding or changing an item, so that I can update the grid somehow in my UI class' access() method but nothing I tried seems to work. I know that push is working because I can see the "Grid updated" message in all UI instances when broadcast is received.

我试图删除视图并重新初始化

I tried to remove the view and re-initialize

navigator.removeView(ContactBookView.NAME);
navigator.addView(ContactBookView.NAME, new ContactBookView());

试图完全清空网格并重新填充

Tried to completely empty the grid and refill

grid.removeAllColumns();
grid.setContainerDataSource(container);

试图通过这种丑陋的解决方法强制网格进行自我更新

Tried to force the grid to update itself using this ugly workaround

grid.setContainerDataSource(grid.getContainerDataSource());

试图执行JavaScript查询以强制UI进行同步

Tried to execute a JavaScript query to force the UIs to sync

JavaScript.getCurrent().execute("javascript:vaadin.forceSync();");

但是这些都不起作用.也许我在做别的事情吗?仅供参考，我的Vaadin版本是7.5.0.

But none of these worked. Maybe I'm doing something else wrong? FYI my Vaadin version is 7.5.0.

我希望收到任何反馈或建议，

I'd appreciate any kind of feedback or advice,

谢谢.

推荐答案

在重新初始化当前视图后，我设法通过重新导航到当前视图来解决了该问题.最终的UI访问方法如下:

I managed to solve the issue by re-navigating to the current view after I reinitialized it. Final UI access method looks like this:

public void receiveBroadcast() {
    access(()->{

        navigator.removeView(ContactBookView.NAME);
        navigator.addView(ContactBookView.NAME, new ContactBookView());
        navigator.navigateTo(ContactBookView.NAME);
        Notification.show("Grid updated", Notification.Type.TRAY_NOTIFICATION);
    });

这样，视图将在后台刷新并推送到UI实例，而无需进行物理刷新.

With this, the view gets refreshed in the background and pushed to the UI instances without having to refresh physically.

我确定可能会有更好的解决方法，这种方法看起来很难看，但目前可以满足我的需求.但是，我仍然会感激任何其他方法.

I'm sure there might be better workarounds and this one seems kind of ugly but it currently satisfies my needs. However, I'd still appreciate any different approach.

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