Number and Date Formatting describes how to format numbers and dates in GWT. GWT does not provide full emulation for the date and number formatting classes (such as java.text.DateFormat, java.text.DecimalFormat, java.text.NumberFormat, and java.TimeFormat). Instead, a subset of the functionality of the JRE classes is provided by com.google.gwt.i18n.client.NumberFormat and com.google.gwt.i18n.client.DateTimeFormat. The major difference between the standard Java classes and the GWT classes is the ability to switch between different locales for formatting dates and numbers at runtime. In GWT, the deferred binding mechanism is used to load only the logic needed for the current locale into the application.
Programming Delayed Logic describes how to defer running code until a later point in time using three classes: Timer, DeferredCommand, and IncrementalCommand. This is useful for scheduling an activity for some time in the future, periodically querying the server or updating the interface, queuing up work to do that must wait for other initialization to finish, and performing a large amount of computation.
Extensible Markup Language (XML) is a data format commonly used in modern web applications. XML uses custom tags to describe data and is encoded as plain text, making it both flexible and easy to work with. Working with XML describes the GWT class library set of types designed for processing XML data.