5.11. Fixing Typoz

Text fields and text views have a built-in typo safety net to help people dodge fat-finger typing mistakes. You can flip the switch in any text view of text field to turn on the iPhone's auto-correction feature to fix misspelled words. This is almost always the right thing to do for text views, which are typically used for the kind of plain-language prose that benefits from this kind of dictionary check. But don't assume every text view or field should have auto-correction. Fields for proper names, addresses, URLs, or other terms that don't show up in dictionaries soon become maddening when auto-correction is enabled, like when the urbane Dr. Hauser "corrects" to Dr. Hayseed, for example.

Give each field a similar once over before turning on the optional auto-capitalization feature for text fields and views. Turn it on for fields where your audience is likely to tap out prose sentences or other values where capitalization is important, but leave it off where it's not appropriate, like password fields, for example. Think carefully about the content you expect for each text field and how the iPhone's editing tools can help or hinder typing the expected values and formats in each. (Providing the proper keyboard layout for a text field is another big piece of this, a topic you'll explore in a moment.)