Data binding works primarily through code generation, and there is very little in the way of runtime overhead. It permits you to use a special expression language in your layout XML files, which gets converted into Java code before your application is compiled. These expressions can call methods, access properties, and are even useful for triggering events. They do have a few restrictions, however: they cannot directly reference the widgets in your user interface, and they cannot create any new objects (they have no new operator). As a result, you'll need to provide your layout files with some utility methods in order to keep things simple, and there are a few guidelines to follow when working with expressions:
- Keep the expressions simple: Don't write application logic into the expressions; rather, create a utility method that can be reused
- Avoid manipulating data directly: As tempting as it might be, ensure that your data is always ready for presentation before...
