iPhone Open Application Development

Tables

Tables are the foundation for most types of selectable lists on the iPhone. Voicemail, recent calls, and even email all use the feature-rich UITable class to display their lists of items. In addition to being a basic list selector, the UITable class includes built-in functionality to add disclosures, swipe-to-delete, animations, labels, and even images.

Creating the Table

A table has three primary components: the table itself, table columns, and table cells (the individual rows in a table). The table's data is queried from a table's data binding. A data binding is an interface used by the table to query information about what data to display, such as filenames, email messages, etc. The data source is an object that responds to this query. When the table is created, a data source must be attached to it in order for the table to display anything. It gets called whenever the table is reloaded or new cells are scrolled into view and tells the table which columns and rows to display, along with the data within them.

Subclassing UITable

For most specialized uses, the table can serve as its own data source. This allows the table class and the table's data to be wrapped cleanly into a single class. To do this, subclass the UITable object to create a new class for your data. In the following example, a subclass named MyTable is created. The base class methods used to initialize and destroy the object are overridden to provide the table portion of the class:

@interface MyTable : UITable ...