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【Compose Multiplatform】Using ROOM Database in CMP - [KSP2] Annotation value is missing in nested annotations

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CrossPlatform#CMP#Kotlin

Introduction

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Important Notes - Current Compatibility Issues with ROOM in CMP

  • Note 1. Room version 2.7.0-alpha01 and above supports KMM.

  • Note 2. When importing ksp, you might encounter issues with version incompatibility due to different Kotlin versions

and fail to Build

In this case, you can check the official GitHub for supported versions: ksp releases

  • Note 3. Using Kotlin with ksp will check for ksp version and Kotlin compatibility

When using Kotlin 2.0.0, during gradle sync you might see errors about version incompatibility

such as Cannot change attributes of configuration ':composeApp:debugFrameworkIosX64' after it has been locked for mutation

or [KSP2] Annotation value is missing in nested annotations

Initially, I found a solution for the KSP2 issue

by adding ksp.useKSP2=true in gradle.properties

However, even after solving this issue

and passing gradle sync

you'll encounter problems when configuring Room with ksp

For example, after setting up ksp(libs.androidx.room.compiler)

you'll consistently get missing dao errors: [ksp] [MissingType]: xxxxx 'data.xxx.xxxDao' references a type that is not present

After researching this issue

Some suggest downgrading the Kotlin version to match ksp

But since the official Wizard for CMP now defaults to Kotlin 2.0.0

and following the principle of using newer rather than older versions XD

If you want to successfully set up Room with Kotlin 2.0.0, you'll need to use a workaround

You can refer to the methods below until an official solution is available

I'll provide methods below

that you can reference

Additionally, I've seen that other developers have already reported issues to the official team:

Implementation

Import - With Kotlin version 1.9
  • Step 1. Import Room

    • Add the following to your .toml file:

    • Add plugin to build.gradle.kts:

    • Add library to build.gradle.kts:

    • Add the following code to the outer layer of build.gradle.kts:

    • If you're using Kotlin version greater than 1.9.20, add the following to gradle.properties:

Import - With Kotlin version 2.0.0

  • Step 1. Modify ksp version:

  • Step 2. Adjust build.gradle.kts:

    • Add build/generated/ksp/metadata to the kotlin block

    • Use the add method to import ksp

    • Add tasks.withType to the outer layer

  • Step 3. Implement RoomDatabase using a workaround

    This is the current workaround

    If you're using Kotlin 2.0.0, you'll need to do this

    as we need to wait for the official team to resolve compatibility issues

Using Room in Practice

Android Main
Implement AppDataBase builder

Koin:

iOS Main
Implement AppDataBase builder

Koin:

Common Main
Implement AppDataBase

Dao

Entity

References