Kotlin Realm Primitive Arrays Workaround for Moshi

RealmTypeAdapter.kt

package de.wdv.apps.yoursingapore.core.moshi

import com.squareup.moshi.JsonAdapter
import com.squareup.moshi.JsonReader
import com.squareup.moshi.JsonWriter
import com.squareup.moshi.Moshi
import de.wdv.apps.yoursingapore.core.realm.RealmIntArray
import de.wdv.apps.yoursingapore.core.realm.RealmLongArray
import de.wdv.apps.yoursingapore.core.realm.RealmStringArray
import java.lang.reflect.Type

/*
 * Copyright 2017 Markus Wedler.
 *
 * 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.
 */

class RealmTypeAdapter {

  companion object {
    val FACTORY: JsonAdapter.Factory = JsonAdapter.Factory { type: Type, annotations: Set<Annotation>, moshi: Moshi ->

      if (type == RealmStringArray::class.java) {
        return@Factory RealmStringArrayAdapter()
      } else if(type == RealmIntArray::class.java) {
        return@Factory RealmIntArrayAdapter()
      } else if(type == RealmLongArray::class.java) {
        return@Factory RealmLongArrayAdapter()
      }

      null
    }
  }

  class RealmStringArrayAdapter : JsonAdapter<RealmStringArray>() {

    override fun fromJson(reader: JsonReader?): RealmStringArray? {
      if (reader != null) {
        val realmStringArray = RealmStringArray()

        val StringList = arrayListOf<String>()
        reader.beginArray()
        while (reader.hasNext()) {
          StringList.add(reader.nextString())
        }
        reader.endArray()
        realmStringArray.joinedStrings = StringList.joinToString(",,,,")

        return realmStringArray
      }
      return null
    }

    override fun toJson(writer: JsonWriter, value: RealmStringArray) {
      // ignore
    }
  }

  class RealmIntArrayAdapter : JsonAdapter<RealmIntArray>() {

    override fun fromJson(reader: JsonReader?): RealmIntArray? {
      if (reader != null) {
        val realmIntArray = RealmIntArray()

        val intList = arrayListOf<Int>()
        reader.beginArray()
        while (reader.hasNext()) {
          intList.add(reader.nextInt())
        }
        reader.endArray()
        realmIntArray.joinedInts = intList.joinToString(",")

        return realmIntArray
      }
      return null
    }

    override fun toJson(writer: JsonWriter, value: RealmIntArray) {
      // ignore
    }
  }

  class RealmLongArrayAdapter : JsonAdapter<RealmLongArray>() {

    override fun fromJson(reader: JsonReader?): RealmLongArray? {
      if (reader != null) {
        val realmLongArray = RealmLongArray()

        val longList = arrayListOf<Long>()
        reader.beginArray()
        while (reader.hasNext()) {
          longList.add(reader.nextLong())
        }
        reader.endArray()
        realmLongArray.joinedLongs = longList.joinToString(",")

        return realmLongArray
      }
      return null
    }

    override fun toJson(writer: JsonWriter, value: RealmLongArray) {
      // ignore
    }
  }
}