danysantiago / kotlin-cursor

Kotlin Annotation Processor to generate fromCursor and toContentValues of data classes.

Kotlin-Cursor

An annotation processor that generates extension functions to convert Kotlin data classes to ContentValues and from Cursor.

Usage

Annotate your data class with @KCursorData

@KCursorData
data class Cat(val name: String)

then once the class is processed a file will be generated with the following extension functions:

fun Cat.toContentValues(): ContentValues { /* ... */ }
fun Cursor.toCat(): Cat { /* ... */ }

Custom types

The following types are supported by default:

• String
• ByteArray
• Double
• Float
• Int
• Long
• Short
• Boolean

Kotlin-Cursor also supports types that are also annotated with @KCursorData. For exmaple:

@KCursorData
data class Bed(val owner: Cat)

For other types, you need to use the @ColumnAdapter annotation and specify a class that implements ColumnTypeAdapter. For example:

Person.kt

data class Person(
    val name: String,
    @ColumnAdapter(CatListAdapter::class)
    val cats: List<Cat>
)

CatListColumnTypeAdapter.kt:

class CatListAdapter : ColumnTypeAdapter<List<Cat>> {
    override fun fromCursor(cursor: Cursor, columnName: String): List<Cat> {
        val listOfCats = cursor.getString(cursor.getColumnIndexOrThrow("cat_list"))
        return listOfCats.split(',').map { Cat(it) }
    }

    override fun toContentValues(values: ContentValues, columnName: String, value: List<Cat>) {
        values.put("cat_list", value.map { it.name }.joinToString(separator = ","))
    }
}

Setup

Add a Gradle dependency:

compile 'com.github.danysantiago:kotlincursor-api:0.1.1'
kapt 'com.github.danysantiago:kotlincursor-compiler:0.1.1'

Snapshots of the development version are available in Sonatype's snapshots repository.

Thanks

To Gabriel Ittner's auto-value-cursor for which this project is based on.