TransitionHandler

TransitionHandler is an assistant for navigating between VIPER modules.

• Example
• Usage
• Extensions
• Requirements
• Communication
• Installation
• Authors

Example

To run the example project, clone the repo, and run pod install from the Example directory first.

Usage

To use a TransitionHandler, all you will need to import TransitionHandler module into your swift file:

import TransitionHandler

For example routers implementations:

import TransitionHandler

/// Open a module with some data, setting presentation style and module output
func openFirstModule(moduleOutput: FirstModuleOutput) {
    transitionHandler
        .openModule(FirstModule.self, withData: "You transition on the First module!")
        .set(navigationController: navigationControllerFactory.navigationController())
        .to(.present)
        .destination { destination in
            destination.hidesBottomBarWhenPushed = true
        }
        .perform()
}

/// Open a module with setting presentation style and internal module output
func openSecondModule(moduleOutput: SecondModuleOutput) {
    transitionHandler
        .openModule(SecondModule.self)
        .to(.navigation(style: .push))
        .then { moduleInput in
            if let moduleOutput = self.transitionHandler.moduleOutput {
                moduleInput.setModuleOutput(moduleOutput)
            }
        }
}

Custom transition:

import TransitionHandler

/// Open complaints with initiate data, setting module output and custom transition
func openComplaints(withComment comment: CommentPlainObject) {
    transitionHandler
        .openModule(ComplaintsModule.self, withData: .comment(object: comment))
        .customTransition()
        .transition { source, destination in
            let navigationController = self.navigationControllerFactory.navigationController(withRootViewController: destination)
            self.halfModalTransitioning = HalfModalTransitioningDelegate(
                config: .init(),
                viewController: source,
                presentingViewController: navigationController
            )
            navigationController.modalPresentationStyle = .custom
            navigationController.transitioningDelegate = self.halfModalTransitioning
            source.present(navigationController, animated: true)
        }
        .then {
            if let moduleOutput = self.transitionHandler.moduleOutput {
                $0.setModuleOutput(moduleOutput)
            }
        }
}

Extensions:

TransitionHandler come with a couple of extensions: Optional and UIViewController.

These methods will help you easily handle optional objects:

// MARK: - Optional

extension Optional {

    /// Unwrap with hint
    public func unwrap(
        _ hint: @autoclosure () -> String? = nil,
        file: StaticString = #file,
        line: UInt = #line
    ) -> Wrapped {
        guard let unwrapped = self else {
            var message = "Required value was nil in \(file), at line \(line)"
            if let hint = hint() {
                message.append(". Debugging hint: \(hint)")
            }
            preconditionFailure(message)
        }
        return unwrapped
    }

    /// Unwrap with error
    public func unwrap(
        _ error: @autoclosure () -> Error,
        file: StaticString = #file,
        line: UInt = #line
    ) -> Wrapped {
        guard let unwrapped = self else {
            var message = "Required value was nil in \(file), at line \(line)"
            message.append(". Debugging hint: \(error().localizedDescription)")
            preconditionFailure(message)
        }
        return unwrapped
    }

    /// Unwrap type with hint
    public func unwrap<T>(
        as type: T.Type,
        _ hint: @autoclosure () -> String? = nil,
        file: StaticString = #file,
        line: UInt = #line
    ) -> T {
        guard let unwrapped = self as? T else {
            var message = "Cannot convert value to type '\(T.self)'"
            if let hint = hint() {
                message.append(". Debugging hint: \(hint)")
            }
            preconditionFailure(message)
        }
        return unwrapped
    }

    /// Unwrap type with error
    public func unwrap<T>(
        as type: T.Type,
        _ error: @autoclosure () -> Error,
        file: StaticString = #file,
        line: UInt = #line
    ) -> T {
        guard let unwrapped = self as? T else {
            var message = "Cannot convert value to type '\(T.self)'"
            message.append(". Debugging hint: \(error().localizedDescription)")
            preconditionFailure(message)
        }
        return unwrapped
    }
}

And these methods allow you to make the work of various manipulations between modules even easier:

// MARK: - TransitionHandler

extension UIViewController: TransitionHandler {

    /// Setup module input
    public var moduleInput: ModuleInput? {
        if let provider = self as? ViewOutputProvider {
            if let result = provider.viewOutput {
                return result
            } else {
                fatalError("Your UIViewController must return ModuleInput!")
            }
        } else {
            fatalError("Your UIViewController must implement protocol 'ViewOutputProvider'!")
        }
    }

    /// Open the desired module
    public func openModule<M>(
        _ moduleType: M.Type
    ) -> ViperTransitionPromise<M.Input> where M: Module, M.View: UIViewController {
        let destination = M.instantiate()
        let promise = ViperTransitionPromise(
            source: self,
            destination: destination,
            for: M.Input.self
        )
        promise.promise { [weak self] in
            self?.present(destination, animated: true, completion: nil)
        }
        return promise
    }

    /// Open the desired module with data
    public func openModule<M>(
        _ moduleType: M.Type,
        withData data: M.Data
    ) -> ViperTransitionPromise<M.Input> where M: AdvancedModule, M.View: UIViewController {
        let destination = M.instantiate(withData: data)
        let promise = ViperTransitionPromise(
            source: self,
            destination: destination,
            for: M.Input.self
        )
        promise.promise { [weak self] in
            self?.present(destination, animated: true, completion: nil)
        }
        return promise
    }

    /// Close current module
    public func closeCurrentModule() -> CloseTransitionPromise {
        let close = CloseTransitionPromise(source: self)
        close.promise { [unowned self] in
            if let parent = self.parent {
                if let navigationController = parent as? UINavigationController {
                    if navigationController.children.count > 1 {
                        navigationController.popViewController(animated: close.isAnimated)
                    } else if let presentedViewController = navigationController.presentedViewController {
                        presentedViewController.dismiss(animated: close.isAnimated)
                    } else if navigationController.children.count == 1 {
                        navigationController.dismiss(animated: close.isAnimated)
                    }
                } else {
                    self.removeFromParent()
                    self.view.removeFromSuperview()
                }
            } else if self.presentingViewController != nil {
                self.dismiss(animated: close.isAnimated)
            }
        }
        return close
    }
}

Requirements

• iOS 11.0+
• tvOS 11.0+
• Xcode 12.0
• Swift 5

Communication

• If you found a bug, open an issue.
• If you have a feature request, open an issue.
• If you want to contribute, submit a pull request.

Installation

Cocoapods

CocoaPods is a dependency manager for Cocoa projects. You can install it with the following command:

$ gem install cocoapods

To install it using CocoaPods, simply add the following line to your Podfile:

use_frameworks!

target "<Your Target Name>" do
pod "TransitionHandler", :git => "https://github.com/Incetro/transition-handler]", :tag => "[0.0.1]"
end

Then, run the following command:

$ pod install

Manually

If you prefer not to use any dependency managers, you can integrate TransitionHandler into your project manually.

Embedded Framework

• Open up Terminal, cd into your top-level project directory, and run the following command "if" your project is not initialized as a git repository:

  $ git init

• Add TransitionHandler as a git submodule by running the following command:

  $ git submodule add https://github.com/incetro/transition-handler.git

• Open the new TransitionHandler folder, and drag the TransitionHandler.xcodeproj into the Project Navigator of your application's Xcode project.

  It should appear nested underneath your application's blue project icon. Whether it is above or below all the other Xcode groups does not matter.

• Select the TransitionHandler.xcodeproj in the Project Navigator and verify the deployment target matches that of your application target.

• Next, select your application project in the Project Navigator (blue project icon) to navigate to the target configuration window and select the application target under the "Targets" heading in the sidebar.

• In the tab bar at the top of that window, open the "General" panel.

• Click on the + button under the "Embedded Binaries" section.

• You will see two different TransitionHandler.xcodeproj folders each with two different versions of the TransitionHandler.framework nested inside a Products folder.

• Select the TransitionHandler.framework.

  You can verify which one you selected by inspecting the build log for your project. The build target for Nio will be listed as either TransitionHandler iOS.

• And that's it!

  The TransitionHandler.framework is automagically added as a target dependency, linked framework and embedded framework in a copy files build phase which is all you need to build on the simulator and a device.

Authors

Gasol: 1ezya007@gmail.com, incetro: incetro@ya.ru

License

TransitionHandler is available under the MIT license. See the LICENSE file for more info.