Useful Kotlin snippets

snippet.kt

//JSON Load from file to object
    private fun loadJSONFromAsset(): JSONObject? {
        var json: JSONObject?
        try {
            val inputStream = applicationContext.assets.open("currencies.json")
            val inputString = inputStream.bufferedReader().use{it.readText()}
            json = JSONObject(inputString)
        } catch (ex: IOException) {
            ex.printStackTrace()
            return null
        }

        return json
    }

//Download JSON from API
//Add anko dependency if large file to prevent crashing
dependencies {
    implementation "org.jetbrains.anko:anko:$anko_version"
}

//Then to read we use
val apiResponse = URL("DATAURL").readText()

//Read and write JSON and strings to Shared prefs
//Declare and Instantiate prefs
lateinit var sharedPref: SharedPreferences
//...
sharedPref = applicationContext.getSharedPreferences("MYPREFS", Context.MODE_PRIVATE)
//Get String
val dataString = sharedPref.getString("STRINGNAME", "")

var dataArray = JSONArray()
//IFJSON
if (!dataString!!.isEmpty()) {
    dataArray = JSONArray(dataString)
}

//Update JSON
val json = JSONObject()
json.put("KEY", ITEMTOSTORE)
dataArray.put(json)

//Write to prefs
val newDataString = dataArray.toString()
val editor = sharedPref.edit()
editor.putString("STRINGNAME", newDataString)
editor.apply()