Perform

Easy dependency injection for storyboard segues.

import Perform

// ...

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: NSIndexPath) {
  let task = taskList[indexPath.row]
  perform(.showTaskDetails) { taskVC in
    taskVC.task = task
  }
}

Usage

Configure your segues:

// Sources/Extensions/Segue.swift
import Perform

extension Segue {
  static var showTaskDetails: Segue<TaskDetailsViewController> {
    return .init(identifier: "ShowTaskDetails")
  }
}

And then use perform(_:prepare:) instead of performSegue(withIdentifier:sender:). That's it!

Type-safe segues

Perform checks the type of the destination view controller and casts it for you, raising an error if your destination view controller is an unexpected type.

Still works if your view controller is embedded in a container

Ever written code like this?

guard let nav = segue.destinationViewController as? UINavigationController,
  let content = nav.rootViewController as? MyViewController
  else { return }

// ... finally! 😭

Perform takes care of this, searching the view controller hierarchy for a view controller of the matching type!

No switch statements in prepareForSegue(_:sender:)

Multiple segues from one view controller? No problem, just prepare each destination view controller right where you perform the segue. No more massive switch statements.

Further reading

For more examples, and a discussion about the motivation and design of Perform, take a look at the introductory blog post.

Installation

Compatibility

Carthage

Add the following to your Cartfile:

github "thoughtbot/Perform" ~> 2.0

Then run carthage update Perform.

Follow the instructions in Carthage's README for up-to-date installation instructions.

CocoaPods

Add the following to your Podfile:

pod "Perform", "~> 2.0"

See the CocoaPods guide for up-to-date installation instructions.

Contributing

See the CONTRIBUTING document.

License

Perform is Copyright (c) 2016 thoughtbot, inc. It is free software, and may be redistributed under the terms specified in the LICENSE file.

About

Perform is maintained and funded by thoughtbot, inc. The names and logos for thoughtbot are trademarks of thoughtbot, inc.

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