Quite often it’s required from iOS applications to be capable of performing search in specific data that is displayed in a tableview. Undoubtably, most of developers have faced that situation, and the most usual approach to that is to use the default controls that the iOS SDK provides. Up to iOS 8, Apple was providing a special control for performing searches in tableviews named UISearchDisplayController. This controller, in conjunction with the UISearchBar was making possible to add search features quite easily in an application. Nevertheless, this belongs to history now.
Since iOS 8 coming, things changed a bit. First of all, the UISearchDisplayController has been deprecated, even though it’s provided as an available control in the Interface Builder’s controls collection in Xcode. A new controller named UISearchController has been given in its place. In spite of this change though, no visual control exists for it in the controls collection in Interface Builder; instead, it must be initialized and configured programmatically, but this is a really easy task, and you’ll see that later on.
Besides all the above, there’s another interesting point regarding the searching in a tableview datasource. iOS SDK provides a predefined appearance for the search bar, and that bar is suitable in many cases. However, when the UI of the app is highly customized, then it’s quite possible the default search bar format not to fit in the whole look and feel of the app. In that case the search bar must be customized appropriately so as to be a non-distinguishable part of the app ecosystem.
So, having said all the above, it’s time to present shortly what this tutorial is all about. I could say that through this text I’m aiming in two things: My first goal is to demonstrate how the new UISearchController presented in iOS 8 can be used so it’s possible to search and filter data using the default iOS search bar. You’ll see through the sample code we are about to write that configuring it it’s an easy process, regardless the fact that a visual control in the Interface Builder doesn’t exist.
My second goal is to show you how you can override the default search bar appearance and customize it according to the app look and feel. As you’ll see next, we have to subclass both the UISearchController and the UISearchBar classes, but the code we’ll add to them is straightforward enough. Actually, the subclasses we’ll implement in the following parts will be made in a quite general way, so you can reuse them in your projects as well.
At this point this introductory part comes to its end, so let’s go to see first of all the demo app details, and then let’s bring it in life.