Tables
A table presents data as a scrolling, single-column list of rows that can be divided into sections or groups. Use a table to display large or small amounts of information cleanly and efficiently in the form of a list. Generally speaking, tables are ideal for text-based content, and often appear as a means of navigation on one side of a split view, with related content shown on the opposite side. See Split Views.
iOS implements two styles of table, plain and grouped.
Plain. Rows can be separated into labeled sections, and an optional index can appear vertically along the right edge of the table. A header can appear before the first item in a section, and a footer can appear after the last item.
Grouped. Rows are displayed in groups, which can be preceded by a header and followed by a footer. This style of table always contains at least one group and each group always contains at least one row. A grouped table doesn’t include an index.
Think about table width. Thin tables can cause truncation and wrapping, making them hard to read and scan quickly at a distance. Wide tables can also be difficult to read and scan, and can take away space from content.
Begin showing table content quickly. Don’t wait for extensive table content to load before showing something. Fill onscreen rows with textual data immediately and show more complex data—such as images—as it becomes available. This technique gives people useful information right away and increases the perceived responsiveness of your app. In some cases, showing stale, older data may make sense until fresh, new data arrives.
Communicate progress as content loads. If a table’s data takes time to load, show a progress bar or spinning activity indicator to reassure people that your app is still alive.
Keep content fresh. Consider updating your table’s content regularly to reflect newer data. Just don’t change the scrolling position. Instead, add the content to the beginning or end of the table, and let people scroll to it when they’re ready. Some apps display an indicator when new data has been added, and provide a control for jumping right to it. It’s also a good idea to include a refresh control, so people can manually perform an update at any time. See Refresh Content Controls.
Avoid combining an index with table rows containing right-aligned elements. An index is controlled by performing large swiping gestures. If other interactive elements reside nearby, such as disclosure indicators, it may be difficult to discern the user’s intent when a gesture occurs and the wrong element may be activated.
For implementation details, see UITableView.
Table Rows
You use standard table cell styles to define how content appears in table rows.
Default. An optional image on the left side of the row, followed by a left-aligned title. It’s a good option for displaying items that don’t require supplementary information. For implementation details, see the UITableViewCellStyleDefault constant of UITableViewCell.
Subtitle. A left-aligned title on one line and a left-aligned subtitle on the next. This style works well in a table where rows are visually similar. The additional subtitle helps distinguish rows from one another. For implementation details, see the UITableViewCellStyleSubtitle constant of UITableViewCell.
Value 1. A left-aligned title with a right-aligned subtitle in a lighter font on the same line. For implementation details, see the UITableViewCellStyleValue1 constant of UITableViewCell.
Value 2. A right-aligned title, followed by a left-aligned subtitle in a lighter font on the same line. For implementation details, see UITableViewCellStyleValue2 constant of UITableViewCell.
All standard table cell styles also allow graphical elements, such as a checkmark or disclosure indicator. Of course, adding these elements decreases the space available for titles and subtitles.
Keep text succinct to avoid clipping. Truncated words and phrases are hard to scan and decipher. Text truncation is automatic in all table cell styles, but it can present more or less of a problem depending on which cell style you use and where truncation occurs.
Consider using a custom title for a Delete button. If a row supports deletion and it helps provide clarity, replace the system-provided Delete title with a custom title.
Provide feedback when a selection is made. People expect a row to highlight briefly when its content is tapped. Then, people expect a new view to appear or something to change, such as a checkmark appearing, that indicates a selection has been made.
Design a custom table cell style for nonstandard table rows. Standard styles are great for use in a variety of common scenarios, but some content or your overall app design may call for a heavily customized table appearance. To learn how to create your own cells, see Customizing Cells in Table View Programming Guide for iOS.
For implementation details, see UITableViewCell.