You've created your form so that users can enter information, and perhaps you've already created the mechanism to save the content to a database or remote server. But what happens when the user enters invalid text or no text? This is where input validation enters the picture.
Input validation validates the input before the save takes place. Assume that the user does not enter text for the title or the message and attempts to save; should she be allowed to save? Of course not!
Unfortunately, a built-in Android validation framework does not exist. Hopefully, in future versions of the Android platform this feature will be introduced. However, you have ways to validate input with the current framework.
The method in which you provide validation to the user is up to you. Here are some common methods in which I've seen developers implement validation:
The Task Reminder application does not provide input validation; ...