Class FileUpload

public class FileUpload
extends Widget
implements HasName
A widget that wraps the HTML <input type='file'> element. This widget must be used with FormPanel if it is to be submitted to a server.

Example

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 ClickListener() {
      public void onClick(Widget sender) {
        form.submit();
      }
    }));

    // Add an event handler to the form.
    form.addFormHandler(new FormHandler() {
      public void onSubmit(FormSubmitEvent 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.setCancelled(true);
        }
      }

      public void onSubmitComplete(FormSubmitCompleteEvent 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);
  }
}

Constructors

FileUpload()Constructs a new file upload widget.

Methods

getFilename()Gets the filename selected by the user.
getName()Gets the widget's name.
setName(String)Sets the widget's name.

Constructor Detail

FileUpload

public FileUpload()
Constructs a new file upload widget.

Method Detail

getFilename

public String getFilename()
Gets the filename selected by the user. This property has no mutator, as browser security restrictions preclude setting it.

Return Value

the widget's filename

getName

public String getName()
Gets the widget's name.

Return Value

the widget's name

setName

public void setName(String name)
Sets the widget's name.

Parameters

name
the widget's new name