InAppSettingsKit

InAppSettingsKit (IASK) is an open source framework to easily add in-app settings to your iOS, Catalyst, or visionOS apps. Normally iOS apps use the Settings.bundle resource to add app-specific settings in the Settings app. InAppSettingsKit takes advantage of the same bundle and allows you to present the same settings screen within your app. So the user has the choice where to change the settings.

IASK not only replicates the feature set of system settings but supports a large number of additional elements and configuration options.

Updating from IASK 2.x? Please read the Release Notes.

• How does it work?
• How to include it?
• App Integration
• Goodies
  • Custom inApp plists
  • Privacy link
  • Open URL
  • Mail Composer
  • Button
  • Multiline Text View
  • Date Picker
  • List Groups
  • Custom Views
  • Section Headers and Footers
  • Extending Child Panes
  • Extending various specifiers
  • Extending Text Fields
  • Customizing Toggles
  • Dynamic MultiValue Lists
  • Settings Storage
  • Notifications
  • Dynamic cell hiding
  • Register default values
• iCloud sync
• Support
• License
• Author

How does it work?

To support traditional Settings.app panes, the app must include a Settings.bundle with at least a Root.plist to specify the connection of settings UI elements with NSUserDefaults keys. InAppSettingsKit basically just uses the same Settings.bundle to do its work. This means there's no additional work when you want to include a new settings parameter. It just has to be added to the Settings.bundle and it will appear both in-app and in Settings.app. All settings types like text fields, sliders, toggle elements, child views etc. are supported.

How to include it?

The source code is available on github. There are several ways of installing it:

Using SPM

To install InAppSettingsKit using Swift Package Manager you can follow the tutorial published by Apple using the URL for the InAppSettingsKit repo with the current version:

1. In Xcode, select “File” → “Add Packages…”
2. Enter https://github.com/futuretap/InAppSettingsKit.git

Using CocoaPods

Add to your Podfile:

pod 'InAppSettingsKit'

Then run pod install.

Using Carthage

Add to your Cartfile:

github "futuretap/InAppSettingsKit" "master"

App Integration

In order to start using IASK add Settings.bundle to your project (File -> Add File -> Settings bundle) and edit Root.plist with your settings (see Apple's documentation on the Schema File Root Content). Read on to get insight into more advanced uses.

To display InAppSettingsKit, instantiate IASKAppSettingsViewController and push it onto the navigation stack or embed it as the root view controller of a navigation controller.

In code, using Swift:

let appSettingsViewController = IASKAppSettingsViewController()
navigationController.pushViewController(appSettingsViewController, animated: true)

In code, using Swift as part of a swift package:

In a modularized app, you might want to move all settings-related code into a separate package, and only reference the InAppSettingsKit dependency there. Your Package.swift would look like this:

let package = Package(
    name: "SettingsPackage",
    platforms: [.iOS(.v17)],
    dependencies: [
        .package(url: "https://github.com/futuretap/inappsettingskit", from: "3.4.0")
    ],
    .target(
        name: "SettingsPackage",
        dependencies: [
            .product(name: "InAppSettingsKit", package: "inappsettingskit"),
        ],
        resources: [
            .copy("InAppSettings.bundle")
        ]
    )
)

(Note that the InAppSettings.bundle directory is also part of the package, and does not belong to the main app anymore.)

Creating an IASKAppSettingsViewController now requires setting its bundle property to the package's bundle:

struct InAppSettingsView: UIViewControllerRepresentable {
    func makeUIViewController(context: Context) -> some UIViewController {
        let iask = IASKAppSettingsViewController(style: .insetGrouped)
        iask.bundle = Bundle.module // IMPORTANT
        return iask
    }

    func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) { }
}

In code, using Objective-C:

IASKAppSettingsViewController *appSettingsViewController = [[IASKAppSettingsViewController alloc] init];
[self.navigationController pushViewController:appSettingsViewController animated:YES];

Via storyboard:

• Drag and drop a Table View Controller embedded into a Navigation Controller into your app and wire the storyboard to your app UI
• Set the Table View Controller class to IASKAppSettingsViewController
• Set the Table View to "Grouped" style.
• If you’re presenting the navigation controller modally:
  • In the Table View Controller set "Show Done Button" under "App Settings View Controller" to "On"
  • Set the delegate comforming to IASKAppSettingsViewControllerDelegate.
  • Implement the delegate method -settingsViewControllerDidEnd: and dismiss the view controller.

The sample application shows how to wire everything up.

Additional changes

To customize the behavior, implement IASKSettingsDelegate and set the delegate property of IASKAppSettingsViewController. For advanced customization needs, subclassing of IASKAppSettingsViewController is supported.

Depending on your project it might be needed to make some changes in the startup code of your app. Your app has to be able to reconfigure itself at runtime if the settings are changed by the user. This could be done in a -reconfigure method that is being called from -applicationDidFinishLaunching as well as in the delegate method -settingsViewControllerDidEnd: of IASKAppSettingsViewController.

Goodies

The intention of InAppSettingsKit was to create a 100% imitation of the Settings.app behavior (see the Apple Settings Application Schema Reference). On top of that, we added a ton of bonus features that make IASK much more flexible and dynamic.

Custom inApp plists

Settings plists can be device-dependent: Root~ipad.plist will be used on iPad and Root~iphone.plist on iPhone. If not existent, Root.plist will be used.

InAppSettingsKit adds the possibility to override those standard files by using .inApp.plist instead of .plist. Alternatively, you can create a totally separate bundle named InAppSettings.bundle instead of the usual Settings.bundle. The latter approach is useful if you want to suppress the settings in Settings.app.

This is the complete search order for the plists:

• InAppSettings.bundle/FILE~DEVICE.inApp.plist
• InAppSettings.bundle/FILE.inApp.plist
• InAppSettings.bundle/FILE~DEVICE.plist
• InAppSettings.bundle/FILE.plist
• Settings.bundle/FILE~DEVICE.inApp.plist
• Settings.bundle/FILE.inApp.plist
• Settings.bundle/FILE~DEVICE.plist
• Settings.bundle/FILE.plist

Privacy link

If the app includes a usage key for various privacy features such as camera or location access in its Info.plist, IASK displays a "Privacy" cell at the top of the root settings page. This cell opens the system Settings app and displays the settings pane for the app where the user can specify the privacy settings for the app.

If you don't want to show Privacy cells, set the property neverShowPrivacySettings to YES.

The sample app defines NSMicrophoneUsageDescription to let the cell appear. Note that the settings page doesn't show any privacy settings yet because the app doesn't actually access the microphone. Privacy settings only show up in the Settings app after first use of the privacy-protected API.

Open URL

InAppSettingsKit adds a new element IASKOpenURLSpecifier that allows to open a specified URL using an external application (i.e. Safari or Mail). The URL to launch is specified in the File parameter. See the sample Root.inApp.plist for details.

Mail Composer

The custom IASKMailComposeSpecifier element allows to send mail from within the app by opening a mail compose view. You can set the following (optional) parameters using the settings plist: IASKMailComposeToRecipents, IASKMailComposeCcRecipents, IASKMailComposeBccRecipents, IASKMailComposeSubject, IASKMailComposeBody, IASKMailComposeBodyIsHTML. Optionally, you can implement

- (BOOL)settingsViewController:(id<IASKViewController>)settingsViewController shouldPresentMailComposeViewController:(MFMailComposeViewController*)mailComposeViewController forSpecifier:(IASKSpecifier*)specifier;

in your delegate to customize the mail (e.g. pre-fill the body with dynamic content, add attachments) modify the appearance of the compose view controller or even block the standard presentation. An alert is displayed if Email is not configured on the device. IASKSpecifier is the internal model object defining a single settings cell. Important IASKSpecifier properties:

• key: corresponds to the Key in the Settings plist
• title: the localized title of settings key
• type: corresponds to the Type in the Settings plist
• defaultValue: corresponds to the DefaultValue in the Settings plist

Button

InAppSettingsKit adds a IASKButtonSpecifier element that allows to call a custom action. Just add the following delegate method:

- (void)settingsViewController:(IASKAppSettingsViewController*)sender buttonTappedForSpecifier:(IASKSpecifier*)specifier;

The sender is always an instance of IASKAppSettingsViewController, a UIViewController subclass. So you can access its view property (might be handy to display an action sheet) or push another view controller. Another nifty feature is that the title of IASK buttons can be overriden by the (localizable) value from NSUserDefaults (or any other settings store - see below). This comes in handy for toggle buttons (e.g. Login/Logout). See the sample app for details.

By default, Buttons are aligned centered except if an image is specified (default: left-aligned). The default alignment may be overridden.

Multiline Text View

Similar to standard text fields, IASKTextViewSpecifier displays a full-width, multi line text view that resizes according to the entered text. It also supports KeyboardType, AutocapitalizationType and AutocorrectionType.

Date Picker

IASKDatePickerSpecifier displays a UIDatePicker to set a date and/or time. It supports the following options:

• DatePickerMode: one of Date, Time, or DateAndTime (see UIDatePickerMode). Default is DateAndTime.
• DatePickerStyle: one of Compact, Wheels, or Inline (see UIDatePickerStyle). Default is Wheels. Feature requires iOS 14 or higher. If the OS doesn't support it, IASK falls back to Wheels.
• MinuteInterval: The interval at which the date picker displays minutes. Default: 1.

There are 3 optional delegate methods to customize how to store and display dates and times:

- (NSDate*)settingsViewController:(IASKAppSettingsViewController*)sender dateForSpecifier:(IASKSpecifier*)specifier;

Implement this if you store the date/time in a custom format other than as NSDate object. Called when the user starts editing a date/time by selecting the title cell above the date/time picker.

- (NSString*)settingsViewController:(IASKAppSettingsViewController*)sender datePickerTitleForSpecifier:(IASKSpecifier*)specifier;

Implement this to customize the displayed value in the title cell above the date/time picker.

- (void)settingsViewController:(IASKAppSettingsViewController*)sender setDate:(NSDate*)date forSpecifier:(IASKSpecifier*)specifier;

Implement this if you store the date/time in a custom format other than an NSDate object. Called when the user changes the date/time value using the picker.

List Groups

List groups (IASKListGroupSpecifier) are an IASK-only feature that allow you to manage a variable number of items, including adding and deleting items. Arrays of tags, accounts, names are typical use cases. A list group consists of a variable number of ItemSpecifier items. The number of these items is determined by your actual content in your NSUserDefaults (or your custom settings store). In other words, ItemSpecifier defines the type of cell, whereas the number of cells and their content comes from NSUserDefaults or your store. Cells can be deleted via swipe if the Deletable parameter is set to YES.

Optionally, a list group also has an AddSpecifier that controls the last item of the list group section. It is used to add items and could be a text field, a toggle, a slider, or a child pane. While the first three create a new item after editing is complete, a child pane presents a modal child view controller to configure a complex item, saved as a dictionary. Such child panes work very similarly to normal child panes with a few differences: They are presented not via push but modally and have a Cancel and Done button in the navigation bar. A new item is created by tapping the Done button.

You may want to specify some validation rules that need to be met before enabling the Done button. This can be achieved with the delegate method:

- (BOOL)settingsViewController:childPaneIsValidForSpecifier:contentDictionary:

The Done button is disabled when returning false from this method. Also note that the contentDictionary is a mutable dictionary. If you change some of the values, the UI will reflect that. This allows you to autocorrect invalid settings.

Custom Views

You can specify your own UITableViewCell within InAppSettingsKit by using the type IASKCustomViewSpecifier. A mandatory field in this case is the Key attribute. Also, you have to support the IASKSettingsDelegate protocol and implement these methods:

- (CGFloat)settingsViewController:(UITableViewController<IASKViewController> *)settingsViewController heightForSpecifier:(IASKSpecifier *)specifier;
- (UITableViewCell*)settingsViewController:(UITableViewController<IASKViewController> *)settingsViewController cellForSpecifier:(IASKSpecifier*)specifier;

Both methods are called for all your IASKCustomViewSpecifier entries. To differentiate them, you can access the Key attribute using specifier.key. In the first method you return the height of the cell, in the second method the cell itself. You should use reusable UITableViewCell objects as usual in table view programming. There's an example in the Demo app.

Optionally you can implement

- (void)settingsViewController:(IASKAppSettingsViewController*)settingsViewController

didSelectCustomViewSpecifier:(IASKSpecifier*)specifier;

to catch tap events for your custom view.

If you specify File, IASKViewControllerClass, IASKViewControllerStoryBoardId, or IASKSegueIdentifier (see below), the selection behavior of a custom view is identical to a child pane and the delegate is not called on selection.

Section Headers and Footers

The FooterText key for Group elements is available in system settings. It is supported in InAppSettingsKit as well. On top of that, we support this key for Multi Value elements as well. The footer text is displayed below the table of multi value options.

You can define a custom header view for PSGroupSpecifier segments by adding a Key attribute and implementing the following method in your IASKSettingsDelegate:

- (UIView *)settingsViewController:(id<IASKViewController>)settingsViewController tableView:(UITableView *)tableView viewForHeaderForSection:(NSInteger)section;

You can adjust the height of the header by implementing the following method:

- (CGFloat)settingsViewController:(id<IASKViewController>)settingsViewController tableView:(UITableView*)tableView heightForHeaderForSection:(NSInteger)section;

For simpler header title customization without the need for a custom view, and provided the -settingsViewController:tableView:viewForHeaderForSection: method has not been implemented or returns nil for the section, implement the following method:

- (NSString *)settingsViewController:(id<IASKViewController>)settingsViewController tableView:(UITableView*)tableView titleForHeaderForSection:(NSInteger)section;

If the method returns nil or a 0-length string, the title defined in the .plist will be used.

This behaviour is similar to custom table view cells. When implementing a method and if you need it, the section key can be retrieved from its index conveniently with:

NSString *key = [settingsViewController.settingsReader keyForSection:section];

Check the demo app for a concrete example.

For footer customization, three methods from the IASKSettingsDelegate protocol can be similarly implemented.

Extending Child Panes

Custom ViewControllers

For child pane elements (PSChildPaneSpecifier), Apple requires a file key that specifies the child plist. InAppSettingsKit allow to alternatively specify IASKViewControllerClass and IASKViewControllerSelector. In this case, the child pane is displayed by instantiating a UIViewController subclass of the specified class and initializing it using the init method specified in the IASKViewControllerSelector. The selector must have two arguments: an NSString argument for the file name in the Settings bundle and the IASKSpecifier. The custom view controller is then pushed onto the navigation stack. See the sample app for more details.

Using Custom ViewControllers from StoryBoard

Alternatively specify IASKViewControllerStoryBoardId to initiate a viewcontroller from main storyboard. Specify IASKViewControllerStoryBoardFile to use a storyboard other than the main storyboard from the app’s Info.plist.

Perform Segues

As an alternative to IASKViewControllerClass and IASKViewControllerSelector for child pane elements (PSChildPaneSpecifier), InAppSettingsKit is able to navigate to another view controller, by performing any segue defined in your storyboard. To do so specify the segue identifier in IASKSegueIdentifier.

Extending various specifiers

Subtitles

The IASKSubtitle key allows to define subtitles for these elements: Toggle, ChildPane, OpenURL, MailCompose, Button. Using a subtitle implies left alignment. A child pane displays its value as a subtitle, if available and no IASKSubtitle is specified. The subtitle can be a localizable String or a Dictionary with localizable subtitles depending on the current value. YES and NO are used as keys for boolean toggle values. The dictionary may contain a __default__ key to define a subtitle if no key is matching.

Text alignment

For some element types, a IASKTextAlignment attribute may be added with the following values to override the default alignment:

• IASKUITextAlignmentLeft (ChildPane, TextField, Buttons, OpenURL, MailCompose)
• IASKUITextAlignmentCenter (ChildPane, Buttons, OpenURL)
• IASKUITextAlignmentRight (ChildPane, TextField, Buttons, OpenURL, MailCompose)

Variable font size

By default, the labels in the settings table are displayed in a variable font size, especially handy to squeeze-in long localizations (beware: this might break the look in Settings.app if labels are too long!). To disable this behavior, add a IASKAdjustsFontSizeToFitWidth Boolean attribute with value NO.

Icons

All element types (except sliders which already have a MinimumValueImage) support an icon image on the left side of the cell. You can specify the image name in an optional IASKCellImage attribute. The ".png" or "@2x.png" suffix is automatically appended and will be searched in the project. Optionally, you can add an image with suffix "Highlighted.png" or "[email protected]" to the project and it will be automatically used as a highlight image when the cell is selected (for Buttons and ChildPanes). If the image is not found as a resource in the project, InAppSettingsKit falls back to SF Symbols.

Extending Text Fields

Placeholder

The IASKPlaceholder key allows to define placeholder for TextField and TextView (IASKTextViewSpecifier).

Content Type

To support autofill based on the content type, add the IASKTextContentType key accepting the (prefix-less) constant names of UITextContentType. Example: to configure a text field with UITextContentTypeEmailAddress, use IASKTextContentType: EmailAddress.

Validation

Text fields can be validated using the delegate callback:

- (IASKValidationResult)settingsViewController:(IASKAppSettingsViewController*)settingsViewController validateSpecifier:(IASKSpecifier*)specifier textField:(IASKTextField*)textField previousValue:(nullable NSString*)previousValue replacement:(NSString* _Nonnull __autoreleasing *_Nullable)replacement;

The callback receives the IASKTextField which is a UITextField subclass to allow styling of the text field in case of a validation error (e.g. red text). It contains a replacement out parameter to replace invalid text. Returning IASKValidationResultFailedWithShake lets the text field shake to visually indicate the validation error.

Customizing Toggles

PSToggleSwitchSpecifier switches use a UISwitch by default. By specifying the option IASKToggleStyle: Checkmark, checkmarks are displayed for selected keys.

Dynamic MultiValue Lists

MultiValue lists (PSMultiValueSpecifier) and radio groups (PSRadioGroupSpecifier) can fetch their values and titles dynamically from the delegate instead of the static Plist. Implement these two methods in your IASKSettingsDelegate:

- (NSArray*)settingsViewController:(IASKAppSettingsViewController*)sender valuesForSpecifier:(IASKSpecifier*)specifier;
- (NSArray<NSString*>*)settingsViewController:(IASKAppSettingsViewController*)sender titlesForSpecifier:(IASKSpecifier*)specifier;

The sample app returns a list of all country codes as values and the localized country names as titles.

MultiValue lists can be sorted alphabetically by adding a true Boolean DisplaySortedByTitle key in the Plist. MultiValue list entries can be given an image. Specify images via the IconNames attribute (next to Values/Titles/ShortTitles etc.).

Settings Storage

The default behaviour of IASK is to store the settings in [NSUserDefaults standardUserDefaults]. However, it is possible to change this behavior by setting the settingsStore property on an IASKAppSettingsViewController. IASK comes with two store implementations: IASKSettingsStoreUserDefaults (the default one) and IASKSettingsStoreFile, which read and write the settings in a file of the path you choose. If you need something more specific, you can also choose to create your own store. The easiest way to create your own store is to create a subclass of IASKAbstractSettingsStore. Only 3 methods are required to override. See IASKSettingsStore.{h,m} for more details.

Notifications

There's a IASKSettingChangedNotification notification that is sent for every changed settings key. The object of the notification is the sending view controller and the userInfo dictionary contains the key and new value of the affected key.

Dynamic cell hiding

Sometimes, options depend on each other. For instance, you might want to have an "Auto Connect" switch, and let the user set username and password if enabled. To react on changes of a specific setting, use the IASKSettingChangedNotification notification explained above.

To hide a set of cells use:

- (void)[IASKAppSettingsViewController setHiddenKeys:(NSSet*)hiddenKeys animated:(BOOL)animated];

or the non-animated version:

@property (nonatomic, strong) NSSet *hiddenKeys;

See the sample app for more details. Including a PSGroupSpecifier key in the hiddenKeys hides the complete section.

Register default values

Settings property lists support the DefaultValue parameter to display default values in case there’s no value stored in NSUserDefaults. However, when the app queries NSUserDefaults for the value, that default value is not propagated. This makes sense since NSUserDefaults doesn’t know about settings property lists.

To initially set values for the various settings keys, NSUserDefaults provides the registerDefaults: method that takes a dictionary of "fallback" values that are returned from NSUserDefaults if no value has been stored. This is typically called at app launch.

However, creating and maintaining that dictionary can be cumbersome and there’s a risk that this dictionary and the settings default values get out of sync.

To address this, IASKSettingsReader provides a method that generates this dictionary by traversing the Root.plist and all child plists and gathering the DefaultValue for all keys.

NSDictionary *defaultDict = [appSettingsViewController.settingsReader gatherDefaultsLimitedToEditableFields:YES];
[NSUserDefaults.standardUserDefaults registerDefaults:defaultDict];

iCloud sync

To sync your NSUserDefaults with iCloud, there's another project called FTiCloudSync which is implemented as a category on NSUserDefaults: All write and remove requests are automatically forwarded to iCloud and all updates from iCloud are automatically stored in NSUserDefaults. InAppSettingsKit automatically updates the UI if the standard NSUserDefaults based store is used.

Support

Please don't use Github issues for support requests, we'll close them. Instead, post your question on StackOverflow with tag inappsettingskit.

License

We released the code under the liberal BSD license in order to make it possible to include it in every project, be it a free or paid app. The only thing we ask for is giving the original developers some credit. The easiest way to include credits is by leaving the "Powered by InAppSettingsKit" notice in the code. If you decide to remove this notice, a noticeable mention on the App Store description page or homepage is fine, too.

Author

Originally developed by Luc Vandal, Ortwin Gentz (Mastodon) took over the development and continues to update the framework. InAppSettingsKit is used in FutureTap’s Where To? app, so we eat our own dog food!

Sponsors wanted

If you would like to support my Open Source work, consider joining me as a sponsor! 💪️ Your sponsorship enables me to spend more time on InAppSettingsKit and other community projects. Thank you!