MojoConfig Android Configuration Generator

Generates Kotlin configuration class out of Lightbend Config configuration file.

Benefits:

• type safety for configuration variables
• obfuscation of configuration variables possible (with external hardening tool)
• no runtime penalty for reading configuration file

The configuration class is generated in the Gradle configuration phase and only if the configuration file has been changed.

It is super fast.

1. Configuration

Create app.config file besides your build.gradle holding your configuration variables.

Variables per application flavor or build type are supported.

The format of the file is HOCON (Human readable JSON).

Example:

app.config

rootProject {
  app {
    main {
      enabled = false
      output {
        dir = "app/src/main/java"
        package = "com.company.app"
        className = "AppConfig"
      }

      config {
        baseUrl = ""
        logHttpRequests = true
        refreshTime = 500
      }
    }

    debug = ${rootProject.app.main} {
      enabled = true
      output {
        dir = "app/src/debug/java"
      }

      config {
        baseUrl = "https://example.debug"
        refreshTime = 1000
      }
    }

    release = ${rootProject.app.main} {
      enabled = true
      output {
        dir = "app/src/release/java"
      }
      config {
        baseUrl = "https://example.release"
        logHttpRequests = false
      }
    }
  }
}

2. Configure Gradle

Add jitpack.io repository in your root project build.gradle and the dependency to the plugin:

buildscript {
    repositories {
        maven { url 'https://jitpack.io' }
    }
    
    dependencies {
        ...
        classpath "com.github.pstanoev.android-mojoconfig:android-mojoconfig:0.2.0"
    }
    ...
}

In your application build.gradle:

apply plugin: 'com.github.pstanoev.android-mojoconfig'

configureApp {
    String configFilename = "app.conf"
    configFile = new File(buildscript.sourceFile.getParentFile(), configFilename)
}

preBuild.dependsOn 'configureApp'

3. Run

Run the gradle task configureApp and it should generate the AppConfig.kt file.

gradlew configureApp

4. Generated file

The generated file AppConfig.kt should look like something like this:

// Generated configuration file. Do not modify!
package com.company.app
...
object AppConfig {
   const val baseUrl: String = "https://example.debug"
   const val refreshTime: Int = 1000
   const val logHttpRequests: Boolean = false
}

5. Cache

The plugin detectes if the config file is changed with file that is generated build/lastUsedConfigFileHash.txt. It only runs when the config file changes. Delete this file to make the plugin regenerate the config class even if the config file is not modified.

6. Configuration options

configFile the configuration file to use. Default app.conf in project dir

enabled master switch to disable it completely without removing the plugin. Default true

rootNodeName the name or nested path (example a.b.c) to the root object in the config. Default rootProject

appNodeName the name or nested path to the app object in the config. Default app.

cacheEnabled should the plugin run only when changes to the config file are detected. Setting this to false will make the plugin run every time the app is built. Default true

debug enable to print debug statements.

All options with default values:

configureApp {
    configFile = new File(project.projectDir, "app.conf")
    enabled = true
    rootNodeName = "rootProject"
    appNodeName = "app"
    cacheEnabled = true
    debug = false
}

7. Root project extensions

To add rootProject.ext variables to the root project, add your key value pairs in .ext of the root node:

rootProject {
  
  # values that will be added added to rootProject.ext
  ext {
    optionalExtVariableA = "something"
    # values from the rest of the config file can be referenced
    optionalExtVariableB = $rootProject.app.something
  }
  
  app {
    something = "yes!"
    ...
  }
}