A good portion of application interfaces is involved in looking up information. Whether an application is performing direct searches, filtering search results, or aiding in input, there are a lot of opportunities to provide lookup assistance.
Since lookup is really a shot in the dark for the user, any real-time feedback will be valued as users work to complete their tasks. There are four lookup patterns we will apply the principle of React Immediately to:
Auto Complete is a powerful pattern that benefits from a reactive interface. As the user types input into a field, a drop-down menu of matching values is displayed. When done right, the choice that best matches will be auto-selected. The user can stop typing and accept the choice that has been matched or choose a different value from the list. The selected value is then entered into the field. Yahoo! Mail uses Auto Complete for email addresses (Figure 13-1).
Figure 13-1. Yahoo! Mail automatically completes email addresses
The Yahoo! Mail Auto Complete has a singular purpose: help users find an email address from their contact list. However, the user ...