Overview

Reporter allows you to broadcast changes to any number of subscribers. Think of Reporter as multidelegate implementation.

Reporter is particularly useful when implementing Controllers/Services or other entities with dynamic data changed over time.

Features

• Report (broadcast) to any number of subscribers in the order of subscription
• React to a report (broadcast) with a Swift closure
• Control subscription lifetime with ReporterBag

Requirements

• Xcode 9.0+
• Swift 4.0+

Installation

Simply add Reporter.swift (~200 lines of code) file to your Xcode project.

Usage

Suppose you have ProfileController entity that provides the following user information (incapsulated into ProfileItem structure):

• user name
• user image

ProfileController keeps ProfileItem in one of the following three discrete states:

• no user information is available
  • ProfileItem is nil
• user information is available, however, user image has to be loaded
  • ProfileItem exists
  • Profileitem.username exists
  • ProfileItem.image is nil
• user information is available and image has been loaded
  • ProfileItem exists
  • both ProfileItem.username and ProfileItem.image exist

As you can see, ProfileController's ProfileItem is dynamic and changes over time. Reporter helps you subscribe to these changes and keep your view with the latest data available.

Here's how the example syncs ProfileVC display with ProfileController data:

self.profileController.itemChanged.subscribe { [weak self] in
    guard
        let this = self,
        let item = this.profileController.item
    else
    {
        return
    }
    this.profileVC.item = item
}

Now it doesn't matter who/what/when initiates ProfileItem updates. ProfileVC is always in sync with the data.

Example

Sample application (in example/ directory) demonstrates a case of user profile loading.

Preview

Architecture

Here's a brief overview of classes under example/App/Profile (in the order of importance):

• ProfileCoordinator
  • creates ProfileVC
  • creates ProfileController
  • requests ProfileController data
  • syncs ProfileVC with ProfileController data
• ProfileController
  • provides ProfileItem and itemChanged (Reporter instance) to report (broadcast) ProfileItem changes
  • provides execution state of load() with isLoading (Reporter instance)
  • simulates ProfileItem loading
    • first, user name
    • second, user image
      • does so after a short delay
      • image update leads to ProfileItem update
• ProfileItem
  • contains user name
  • contains user image
• ProfileVC
  • displays all three discrete stages of ProfileItem availability:
    • not available
    • only user name is available
    • both user name and image are available

Images

Loaded image represents Hanar race from Mass Effect.

License

Reporter is released under the ZLIB license.