Override

A micro-library that makes it easy to override values in your iOS apps.

What it is

If your iOS app ever has a string or some other hard-coded data that - for whatever reason - you'd like to change, Override makes that possible easily. For example: if you change an endpoint, you can submit an update with the new URL, but what about users on older builds? Override those!

Simply stick a JSON file anywhere on the internet (HTTPS required because it's 2017), implement Override, and be able to flip switches in your app from afar.

What it isn't

Override doesn't provide a server-side component, rather it allows you to bring your own (or simply upload a JSON file).

Override doesn't lock you into a specific data model, instead it uses UserDefaults, letting you use them directly or enhance them to fit your app.

How you use it

Install with CocoaPods (pod 'Override') or manually (download Override.swift into your project).

Put a flat JSON file on a server accessible with an HTTPS URL. Example:

{
  "endpointVersion": "v1",
  "offerFreeTrial": false
}

In AppDelegate.swift's didFinishLaunchingWithOptions method (or another one if you'd prefer), initialize the class:

let override = Override()

Then (optionally) set your preferred UserDefaults instance:

override.userDefaultsInstance = UserDefaults.standard

Then (optionally, but recommended) set your initial values for each key:

override.initialValues = [
  "endpointVersion": "v1",
  "offerFreeTrial": false
]

Finally, request an update from your JSON file and (optionally) handle it:

override.update(from: "https://tylr.us/testing/override.json") {success in
  print(success)
}

Note: For maximum flexibility, you can include your JSON URL as a value in your initialValues/JSON file, passing the UserDefaults value for your assigned key in the update method.

Once it's implemented, the app will check on each launch (or whenever the update method is fired), so if you decide to change endpoint versions, offer that free trial, or even change your JSON URL, just update the file on your server and your users will see the updates.