Learning the iOS 4 SDK for JavaScript Programmers

Creating a Date Object

Working with the JavaScript Date object is the bane of many programmers, mostly due to the need for web pages to operate for a global audience where formats and time zones confound even the best of plans. If you thought that the JavaScript Date object was a headache, I don’t have good news for you on the Cocoa Touch side of things. To perform even simple tasks often requires navigating through multiple classes dealing with dates, calendars, and date components—and that’s not even getting into the formatted display of date and time data. That’s one reason why the discussion involving dates is spread across a few sections in this chapter.

Despite this potentially fearsome complexity, one factor that is actually much simpler to deal with in an iOS app is obtaining a valid date and time input from the user. The whole issue of validating text field entries in web forms thankfully becomes a nonissue with the aid of the UIDatePicker control, shown in Figure 9-1.

Figure 9-1. The UIDatePicker control

Adding a UIDatePicker to Workbench

If you want to try out some of the examples dealing with dates, I recommend you add (at least temporarily) a UIDatePicker control to the Workbench app, as well as a method that executes when a user chooses a date. Begin by adding a little bit of code to the WorkbenchViewController class files. First, add the following method declaration to ...