Step 2: Add a Backend module + buildSrc for dependency management

January 05, 2022

What do we need to serve our pizza?

Right! A backend.

And you know what, we can do that with Kotlin. So let’s start.

Add another module to our basic setup: backend. Click on the project and choose New -> Module. Name it “backend”. Choose “No Activity” when asked to create one.

If you check out the project settings.gradle.kts, you will see that the backend module is included in the project now.

rootProject.name = "kmpizza"
include(":androidApp")
include(":shared")
include(":backend")

As our recipe collection is going to grow into a big project for multiple platforms, we’ll need to keep our dependencies clean and organised. To do so, we’ll setup buildSrc for dependency management. Add a new directory to the root folder and name it “buildSrc”.

In this module create Versions.kt and build.gradle.kts to match the following file structure:

In Versions.kt file you wil keep all the dependencies for different modules in this project.

Add the following to the build.gradle.kts file:

plugins {
   `kotlin-dsl`
}

repositories {
   gradlePluginPortal()
   maven("https://dl.bintray.com/kotlin/kotlinx/")
}

To make sure we haven’t broken anything yet, sync the project, choose androidApp configuration and run the app.

You’ll see a “Hello, Android!” on your device, which is an initial setup that comes with the KMM Application Android Studio Project.

If you want to try it in XCode, open iosApp.xcworkspace.

Then run it on a simulator and you’ll see a “Hello, iOS!” screen. Great, everything is still working 😉

Or is it? If you try running it on a real device you may get an error Signing for "iosApp" requires a development team. Select a development team in the Signing & Capabilities editor. Let’s quickly fix it. Select the project name in XCode and go to Signing&Capabilites in the project editor. There change your team to Personal Team, something like this:

Now you may see another error if you try running the app again: Command PhaseScriptExecution failed with a nonzero exit code 😱

No worries, we’ll fix it too. First, you need to sync the gradle project in Android Studio, then go to the iosApp directory in your terminal and run pod install there.

Now try running again. If you get a warning like this

Then go to Settings -> General -> Device Management and choose to trust your developer account.

Run the app again. Finally we see the greeting on a real device!

And just like this, one step at a time we’ll continue building our multiplatform app. 🍕