iOS 9 App Search Tutorial: Introduction to App Search

An especially savvy user could launch your app by using Siri or searching for it in Spotlight, but neither of these tools help the user find what they want inside a non-Apple app. Meanwhile, Apple makes things like contacts, notes, messages, email and apps directly searchable within Spotlight. The user simply taps on the search result and goes straight to the content. No fair!

Sometimes it seems like Apple keeps all the fun features to itself, like using Spotlight. The good news is that after Apple developers finish playing around with a feature and feel it’s ready for showtime, it often lets the masses play too, like it did with app extensions in iOS 8.

With iOS 9, Apple is passing a very exciting feature off to the rest of us; third party developers now have the ability to make their content searchable through Spotlight!

In this iOS 9 app search tutorial you’ll discover the power of app searching, and learn how easy it is to integrate into your own apps.

App search APIs

App search in iOS 9 comprises three main aspects. Each is broken into separate APIs that achieve distinct results, but they also work in concert with one another:

• NSUserActivity
• Core Spotlight
• Web markup

NSUserActivity

Being a clever little feature, this aspect of app search makes use of the same NSUserActivity API that enables Handoff in iOS 8.

In iOS 9, NSUserActivity has been augmented with some new properties to enable search. Theoretically speaking, if a task can be represented as an NSUserActivity to be handed off to a different device, it can be stored in a search index and later continued on the same device. This enables you to index activities, states and navigation points within your app, allowing the user to find them later via Spotlight.

For example, a travel app might index hotels the user has viewed, or a news app might index the topics the user browsed.

Core Spotlight

The second, and perhaps most “conventional” aspect of app search is Core Spotlight, which is what the stock iOS apps like Mail and Notes use to index content. While it’s nice to allow users to search for previously accessed content, you might take it a step further by making a large set of content searchable in one go.

You can think of Core Spotlight as a database for search information. It provides you with fine-grained control of what, when and how content is added to the search index. You can index all kinds of content, from files to videos to messages and beyond, as well as updating and removing search index entries.

Core Spotlight is the best way to provide full search capabilities of your app’s private content.

This tutorial will focus on what is required to get Spotlight results by using NSUserActivity described above. The full version of this tutorial in iOS 9 by Tutorials shows how to fully index your content by using Core Spotlight.

Web markup

The third aspect of app search is web markup, which is tailored towards apps that mirror their public content from a web site. A good example is Amazon, where you can search the millions of products it sells, or even raywenderlich.com. Using open standards for marking up web content, you can show it in Spotlight and Safari search results and even create deep links within your app.

This tutorial will not cover web markup, but you can learn all about it in Chapter 3, “Your App On The Web” of iOS 9 by Tutorials.

Getting started

You’ll work with a sample app named Colleagues that simulates a company address book. It provides an alternative to adding every coworker to your contacts, instead providing you with a directory of your colleagues. To keep things simple, it uses a local dataset, comprising of a folder of avatar images and a JSON file that contains employee information. In the real world, you would have a networking component that fetches contact data from a web-service. This is a tutorial, so JSON it is. Download and open the starter project, and before you do anything, build and run the app.

You’ll immediately see a list of employees. It’s a small startup, so there’s only 25 staff. Select Brent Reid from the list to see all of his details. You’ll also see a list of employees who are in the same department. And that is the extent of the app’s features — it’s very simple!

Search would make this app infinitely better. As it stands, you can’t even search while you’re in the app. You won’t add in-app search, but instead add the ability to search from outside the app with Spotlight!

Sample project

Take a moment to familiarize yourself with the project’s codebase. There are two targets: Colleagues which is the app itself, and EmployeeKit which is a framework to facilitate interactions with the employee database.

From the EmployeeKit group in Xcode, open Employee.swift. This is the model for an employee that has all the properties you might expect. Employee instances are initialized using a JSON model, which are stored under the Database group in a file named employees.json.

Moving on, open EmployeeService.swift. At the top of the file is an extension declaration, and there is a method named destroyEmployeeIndexing() marked with TODO. You’ll fill out this method’s implementation later. This method will destroy any indexing that has occurred.

There’s more to the EmployeeKit target, but it’s not related to app searches, so there’s no need to go into it now. By all means though, feel free to poke around!

Open AppDelegate.swift in the Colleagues group. Notice there is only one method in here: application(_:didFinishLaunchingWithOptions:). This implementation checks if Setting.searchIndexingPreference is set to .Disabled, if so it will destroy any search indexing that has occurred.

You don’t need to do anything other than just be aware of this setting. You can change the setting in the iOS system Settings app under “Colleagues”.

That concludes your tour. The rest of the code is view controller logic that you’ll modify, but you don’t need to know all of it to work with app search.