Question: Is there a programmatic way to read all the widget a GWT page or Panel contains? 

I have several error labels in my form, all suffixed by "ErrorLabel" and I'd like to find them and clear them. I can do a list of them, but I figured out I can actually automate that if I had some...

I am using UiBinder.

Answer: 
The simplest solution is to add a class name to all the labels - for example, "errorLabel", and add the following line to your CSS file:

```
.hide .errorLabel {display: none}

```

Then, if you need to hide/show all of these labels, you can do it with a single line of code:

```
parentPanel.addStyleName("hide");
parentPanel.removeStyleName("hide");

```
Something like that

```
private void myFunction(RootPanel panel) {
for (Widget w : panel) {
    if(w instanceof Label){
       //do something
    }
}
}

```