通过Kotlin中的匿名内部对象修改外部类

Question

I'm writing my first Android app in Kotlin.

What I'm trying to do is to issue an HTTP request (Volley) in order to fetch some data which shall be written into the object's properties.
That works fine so far until the Volley response listener is left. Afterwards the properties are back to null.

This is the caller:

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val haiku = Haiku(applicationContext)
        haiku.load() // populates 3 properties (author, body, title)
        haiku.show() // author, body, title are back to null here
    }
}

The callee:

class Haiku(var context: Context? = null, var title: String? = null, var body: String? = null,
        var author: String? = null) : Parcelable {  // parcelable implementaion left out here


    fun load() {
        val stringRequest = object : StringRequest(Request.Method.GET, EndPoints.URL_GET_HAIKU,
            Response.Listener { response ->
                try {
                    val json = JSONObject(response) // proper payload arrives
                    val haiku = json["haiku"] as JSONObject
                    this@Haiku.title = haiku["title"] as String // all properties look alright here
                    this@Haiku.author = haiku["author"] as String
                    this@Haiku.body = haiku["body"] as String
                } catch (e: JSONException) {
                    Toast.makeText(context, R.string.haiku_not_fetched,
                            Toast.LENGTH_LONG).show()
                }
            },
            Response.ErrorListener { error ->
                Toast.makeText(context, R.string.haiku_not_fetched,
                        Toast.LENGTH_LONG).show()
            }) {
        }
        VolleySingleton.instance?.addToRequestQueue(stringRequest)
    }

    fun show() {  // when called after the load method title, body, author are back to null
        val intent = Intent(context, HaikuDisplayActivity::class.java)
        intent.putExtra(EXTRA_HAIKU, this)
        context!!.startActivity(intent)
    }
}

It's probably an issue with the object's scope but I wasn't able to figure out why the values arn't preserved. Thanks a lot for any kind for help!

Answer 1

The question was answered in the comments. The HTTP request handn't returned yet when the show() method was called. I got confused by the debugger because it makes it look like it's already there.

Thanks @Chisko