Adding variables at build time in Xcode

Question

I have some dynamic values I need to change based on the type of build I am doing in Xcode.

I have created 2 schemes DEV and PROD and set environment variables in each

I then consume these in code as follows

var serviceDomain: String {
    let envVar = ProcessInfo.processInfo.environment
    guard let value = envVar["APP_SERVICE_DOMAIN"] else { fatalError("Missing APP_SERVICE_DOMAIN enviroment variable") }
    return value
}

Is this the correct way to approach this?

Once an app is compiled, should these values now be bundled with it?

I have an issue in that once I've stopped my simulator, if I try to open an app built this way, it crashes and I suspect the environment variables aren't present anymore.

In short, I would like a build for dev that uses one set of variables and a build for release / production that uses another.

Regarding environment vars scope, you are right: they are defined by Xcode and, as such, won’t be be present when running your app outside the IDE. You will need to define default values in your code (or an external file) if you want to follow this approach. — Paulo Mattos
– Paulo Mattos, Commented Jan 15, 2019 at 12:44

Sweeper · Accepted Answer · 2019-01-15 08:06:15Z

6

You don't need environment variables at all!

Go to build settings and search for active compilation conditions:

Add DEBUG for Debug and RELEASE for Release as I have done here.

Then declare your variables. Let's say you want a to be 1 in release mode, and 2 in debug mode,

#if RELEASE
let a = 1
#elseif DEBUG
let a = 2
#endif

And that's it!

The compiler will choose one of the values to compile, depending on your scheme's Build Configuration. Here, it is debug, so 2 will be used:

More details on this #if thingy

answered Jan 15, 2019 at 8:06

Sweeper

291k23 gold badges257 silver badges432 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Harry Blue Over a year ago

Thank you, so I should use that if statement in perhaps some sort of constants file I assume?

Sweeper Over a year ago

@HarryBlue Yes you could put it in a constant file, or anywhere else you like. It doesn't matter.

Collectives™ on Stack Overflow

Adding variables at build time in Xcode

1 Answer 1

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Linked

Related