Secondary Constructor param - kotlin

Question

Can someone please help me work this out? My object had 3 main parameters, all Strings. I now want to add a secondary constructor with an single emum parameter, which in turn would set each of the 3 original params, as follows;
class MyObject(var string1: String, var string2: String, var string3: String)
{
constructor(presetCode: PresetCode ) : this("", "", "")
{
when (presetCode)
{
PresetCode.Code1 ->
{
string1 = "aaa"
string2 = "bbb"
string3 = "ccc"
}
}
}
var anotherObject = AnotherObject(string1)
}
The issue is AnotherObject(string1) isn't working, as string1 is just an empty string.
how can I set the 3 params using this secondary constructor and then successfully call AnotherObject(string1)?
thanks

Answer 1

One option is to replace the secondary constructor with an invoke() method on the companion object:
class MyObject(var string1: String, var string2: String, var string3: String) {
companion object {
operator fun invoke(presetCode: PresetCode) = when (presetCode) {
PresetCode.Code1 -> MyObject("aaa", "bbb", "ccc")
else -> MyObject("", "", "")
}
}
var anotherObject = AnotherObject(string1)
}
In use, it looks just like a constructor call, e.g.:
val o = MyObject(PresetCode.Code1)
This approach is simple, concise, and very flexible.  (For example, it could return a cached instance instead of creating a new one.)

Answer 2

Here is a solution I found based on your class design which requires single AnotherObject construction per MyObject instance:
class MyObject
{
constructor(s1: String, s2: String, s3: String)
{
string1 = s1
string2 = s2
string3 = s3
anotherObject = AnotherObject(string1)
}
constructor(presetCode: PresetCode)
{
when (presetCode)
{
PresetCode.Code1 ->
{
string1 = "aaa"
string2 = "bbb"
string3 = "ccc"
}
else ->
{
string1 = ""
string2 = ""
string3 = ""
}
}
anotherObject = AnotherObject(string1)
}
var string1: String
var string2: String
var string3: String
var anotherObject: AnotherObject
}
Hope this helps.