public class FileUpload extends FocusWidget implements HasName, HasChangeHandlers, HasEnabled
FormPanel if it is to
be submitted to a server.
public class FormPanelExample implements EntryPoint {
public void onModuleLoad() {
// Create a FormPanel and point it at a service.
final FormPanel form = new FormPanel();
form.setAction("/myFormHandler");
// Because we're going to add a FileUpload widget, we'll need to set the
// form to use the POST method, and multipart MIME encoding.
form.setEncoding(FormPanel.ENCODING_MULTIPART);
form.setMethod(FormPanel.METHOD_POST);
// Create a panel to hold all of the form widgets.
VerticalPanel panel = new VerticalPanel();
form.setWidget(panel);
// Create a TextBox, giving it a name so that it will be submitted.
final TextBox tb = new TextBox();
tb.setName("textBoxFormElement");
panel.add(tb);
// Create a ListBox, giving it a name and some values to be associated with
// its options.
ListBox lb = new ListBox();
lb.setName("listBoxFormElement");
lb.addItem("foo", "fooValue");
lb.addItem("bar", "barValue");
lb.addItem("baz", "bazValue");
panel.add(lb);
// Create a FileUpload widget.
FileUpload upload = new FileUpload();
upload.setName("uploadFormElement");
panel.add(upload);
// Add a 'submit' button.
panel.add(new Button("Submit", new ClickHandler() {
public void onClick(ClickEvent event) {
form.submit();
}
}));
// Add an event handler to the form.
form.addSubmitHandler(new FormPanel.SubmitHandler() {
public void onSubmit(SubmitEvent event) {
// This event is fired just before the form is submitted. We can take
// this opportunity to perform validation.
if (tb.getText().length() == 0) {
Window.alert("The text box must not be empty");
event.cancel();
}
}
});
form.addSubmitCompleteHandler(new FormPanel.SubmitCompleteHandler() {
public void onSubmitComplete(SubmitCompleteEvent event) {
// When the form submission is successfully completed, this event is
// fired. Assuming the service returned a response of type text/html,
// we can get the result text here (see the FormPanel documentation for
// further explanation).
Window.alert(event.getResults());
}
});
RootPanel.get().add(form);
}
}
The developer should be aware that most browsers do not allow styling
many properties of the rendered input-file element because of security restrictions.
You can style certain properties like position, visibility, opacity, etc. But size,
color, backgrounds etc. will not work either using css or calling widget methods like setSize().
UIObject.DebugIdImpl, UIObject.DebugIdImplEnabledeventsToSinkDEBUG_ID_PREFIX, MISSING_ELEMENT_ERROR, SETELEMENT_TWICE_ERROR| Modifier | Constructor and Description |
|---|---|
|
FileUpload()
Constructs a new file upload widget.
|
protected |
FileUpload(Element element)
This constructor may be used by subclasses to explicitly use an existing
element.
|
| Modifier and Type | Method and Description |
|---|---|
HandlerRegistration |
addChangeHandler(ChangeHandler handler)
Adds a
ChangeEvent handler. |
void |
click()
Programmatic equivalent of the user clicking the button, opening
the file selection browser.
|
java.lang.String |
getFilename()
Gets the filename selected by the user.
|
java.lang.String |
getName()
Gets the widget's name.
|
boolean |
isEnabled()
Gets whether this widget is enabled.
|
void |
setEnabled(boolean enabled)
Sets whether this widget is enabled.
|
void |
setName(java.lang.String name)
Sets the widget's name.
|
static FileUpload |
wrap(Element element)
Creates a FileUpload widget that wraps an existing <input
type='file'> element.
|
addBlurHandler, addClickHandler, addClickListener, addDoubleClickHandler, addDragEndHandler, addDragEnterHandler, addDragHandler, addDragLeaveHandler, addDragOverHandler, addDragStartHandler, addDropHandler, addFocusHandler, addFocusListener, addGestureChangeHandler, addGestureEndHandler, addGestureStartHandler, addKeyboardListener, addKeyDownHandler, addKeyPressHandler, addKeyUpHandler, addMouseDownHandler, addMouseListener, addMouseMoveHandler, addMouseOutHandler, addMouseOverHandler, addMouseUpHandler, addMouseWheelHandler, addMouseWheelListener, addTouchCancelHandler, addTouchEndHandler, addTouchMoveHandler, addTouchStartHandler, getFocusImpl, getTabIndex, onAttach, removeClickListener, removeFocusListener, removeKeyboardListener, removeMouseListener, removeMouseWheelListener, setAccessKey, setFocus, setTabIndexaddAttachHandler, addBitlessDomHandler, addDomHandler, addHandler, asWidget, asWidgetOrNull, createHandlerManager, delegateEvent, doAttachChildren, doDetachChildren, ensureHandlers, fireEvent, getHandlerCount, getHandlerManager, getLayoutData, getParent, isAttached, isOrWasAttached, onBrowserEvent, onDetach, onLoad, onUnload, removeFromParent, replaceElement, setLayoutData, setParent, sinkEvents, unsinkEventsaddStyleDependentName, addStyleName, ensureDebugId, ensureDebugId, ensureDebugId, getAbsoluteLeft, getAbsoluteTop, getElement, getOffsetHeight, getOffsetWidth, getStyleElement, getStyleName, getStyleName, getStylePrimaryName, getStylePrimaryName, getTitle, isVisible, isVisible, onEnsureDebugId, removeStyleDependentName, removeStyleName, resolvePotentialElement, setElement, setElement, setHeight, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setTitle, setVisible, setVisible, setWidth, sinkBitlessEvent, toStringclone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, waitfireEventpublic FileUpload()
protected FileUpload(Element element)
element - the element to be usedpublic static FileUpload wrap(Element element)
RootPanel.detachNow(Widget).element - the element to be wrappedpublic HandlerRegistration addChangeHandler(ChangeHandler handler)
HasChangeHandlersChangeEvent handler.addChangeHandler in interface HasChangeHandlershandler - the change handlerHandlerRegistration used to remove this handlerpublic java.lang.String getFilename()
public java.lang.String getName()
HasNamepublic boolean isEnabled()
isEnabled in interface HasEnabledisEnabled in class FocusWidgettrue if the widget is enabledpublic void setEnabled(boolean enabled)
setEnabled in interface HasEnabledsetEnabled in class FocusWidgetenabled - true to enable the widget, false
to disable itpublic void setName(java.lang.String name)
HasNamepublic void click()
NOTE: in certain browsers programmatic click is disabled if the element display is none, for instance in webkit you have to move the element off screen.