Predicates and sorting in iOS Swift - UI Render Trace

Component - Predicates and sorting

This UI component shows a list of items filtered by a condition (predicate) and sorted by a chosen property. Users see only the items that match the filter, arranged in order.

Widget Tree

UITableViewController
└── UITableView
    └── UITableViewCell (multiple)

The main screen is a UITableViewController that manages a UITableView. The table view displays multiple UITableViewCells, each representing one filtered and sorted item.

Render Trace - 3 Steps

Step 1: UITableViewController

Step 2: UITableView

Step 3: UITableViewCell

State Change - Re-render

Trigger:User changes filter criteria or sorting option

Before

Table shows all items unsorted and unfiltered

→

After

Table shows only items matching predicate, sorted by selected key

Re-renders:UITableView reloads all visible UITableViewCells

UI Quiz - 3 Questions

What does the predicate do in this UI?

A Changes the color of the list items

B Filters the list to show only matching items

C Adds new items to the list

D Sorts the list alphabetically

Key Insight

Using predicates and sorting together lets users see only the items they want, arranged clearly. The UITableView reloads efficiently when data changes, keeping the UI responsive and easy to understand.