🏗 Automatically generating builders 👷 for Kotlin data classes.

_{^{(incremental)}}

Usage

For a working usage of this library see the sample/ module.

1. (optional - for Android projects) add to your app's build.gradle:

   android {  
       kotlinOptions.jvmTarget = '1.8'  
   }  

2. Add to @DataClassBuilder annotation your data class

   @DataClassBuilder  
   data class User(  
       val name: String = "Anonymous",  
       val age: Int,  
       val photoUrl: String? = null  
   ) {  
       companion object //<-- OPTIONAL companion object
   }  

3. Use the generated builder to create your data class:

   //1. Java-style builder
   val jane = dataClassBuilder(User::class)
       .name("Jane")
       .age(30)
       .build()

   or

   //2. Kotlin DSL builder
   val jane = buildDataClass(User::class) {
       name = "Jane"
       age = 30
   }

   or

   //3. Java-style builder through companion (generated if companion is present)
   val jane = User.dataClassBuilder()
       .name("Jane")
       .age(30)
       .build()

   or

   //4. Kotlin DSL builder through companion (generated if companion is present)
   val jane = User.buildDataClass {
       name = "Jane"
       age = 30
   }

Java interop

For easy interoperation with Java code add this companion object to your data class:

@DataClassBuilder  
data class User(  
    val name: String = "Anonymous",  
    val age: Int,  
    val photoUrl: String? = null  
) {  
    companion object {
        @JvmStatic
        fun builder() = dataClassBuilder(User::class) //NOT specifying return type explicitly on purpose
    }
}  

(something like this might be generated by the library in one of the future implementations)

Including In Your Project

Add in your build.gradle:

repositories {  
    maven { url 'https://dl.bintray.com/blipinsk/maven/' }  
}  
  
dependencies {  
    kapt "com.bartoszlipinski:data-class-builder-compiler:0.1.0"  
    implementation "com.bartoszlipinski:data-class-builder:0.1.0"  
}  

Important

The presence of data class parameters is verified in runtime.

E.g.

1. For data class:

   @DataClassBuilder  
   data class User(  
       val name: String = "Anonymous",  
       val age: Int // <-- no default value specified
   )

2. When creating:

   buildDataClass(User::class) {
       name = "John"
       // not setting the necessary `age`
   }

3. ☝️ this will crash 💥 in runtime ☝️

Developed by

• Bartosz Lipiński

License

Copyright 2020 Bartosz Lipiński  
  
Licensed under the Apache License, Version 2.0 (the "License");  
you may not use this file except in compliance with the License.  
You may obtain a copy of the License at  

   http://www.apache.org/licenses/LICENSE-2.0  

Unless required by applicable law or agreed to in writing, software  
distributed under the License is distributed on an "AS IS" BASIS,  
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  
See the License for the specific language governing permissions and  
limitations under the License.