use view model factory to create the OrderInputViewModel

Author: gigiyy

exampleAppJapan/src/main/kotlin/it/trade/android/japanapp/ui/orderinput/OrderInputFragment.kt

@@ -5,17 +5,19 @@ import android.arch.lifecycle.ViewModelProviders
 import android.opengl.Visibility
 import android.os.Bundle
 import android.support.v4.app.Fragment
+import android.text.Editable
+import android.text.TextWatcher
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.widget.EditText
 import it.trade.android.japanapp.R
 import kotlinx.android.synthetic.main.order_input_fragment.*
 import kotlinx.android.synthetic.main.order_input_fragment.view.*
 
 class OrderInputFragment : Fragment() {
 
     companion object {
-        fun newInstance() = OrderInputFragment()
         fun newInstance(symbol: String): OrderInputFragment {
             val args = Bundle()
             args.putString("symbol", symbol)
@@ -26,18 +28,17 @@ class OrderInputFragment : Fragment() {
     }
 
     private lateinit var viewModel: OrderInputViewModel
+    private lateinit var symbol: String
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                               savedInstanceState: Bundle?): View {
+        symbol = arguments?.getString("symbol") ?: "8703"
         return inflater.inflate(R.layout.order_input_fragment, container, false)
     }
 
     override fun onActivityCreated(savedInstanceState: Bundle?) {
         super.onActivityCreated(savedInstanceState)
-        viewModel = ViewModelProviders.of(activity!!).get(OrderInputViewModel::class.java)
-        arguments?.getString("symbol")?.let {
-            viewModel.init(it)
-        }
+        viewModel = ViewModelProviders.of(activity!!, OrderInputViewModelFactory(symbol)).get(OrderInputViewModel::class.java)
         viewModel.getOrderModel().observe(this, Observer { orderForm ->
             orderForm?.run {
                 tvSymbolName.text = symbol.name
@@ -96,4 +97,16 @@ class OrderInputFragment : Fragment() {
         }
     }
 
+    fun EditText.onChange(cb: (String) -> Unit) {
+        this.addTextChangedListener(object : TextWatcher {
+            override fun afterTextChanged(s: Editable?) {
+                cb(s.toString())
+            }
+
+            override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
+
+            override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
+        })
+    }
+
 }

exampleAppJapan/src/main/kotlin/it/trade/android/japanapp/ui/orderinput/OrderInputViewModel.kt

@@ -3,15 +3,20 @@ package it.trade.android.japanapp.ui.orderinput
 import android.arch.lifecycle.LiveData
 import android.arch.lifecycle.MutableLiveData
 import android.arch.lifecycle.ViewModel
+import android.arch.lifecycle.ViewModelProvider
+import android.util.Log
 
-class OrderInputViewModel : ViewModel() {
+private const val TAG = "OrderInputViewModel"
+
+class OrderInputViewModel(private val symbol: String) : ViewModel() {
     private lateinit var orderForm: MutableLiveData<OrderForm>
 
     fun getOrderModel(): LiveData<OrderForm> {
         if (!this::orderForm.isInitialized) {
+            Log.d(TAG, "initialized.")
             orderForm = MutableLiveData()
             orderForm.value = OrderForm(
-                    TradeItSDKHolder.getSymbolProvider().getJapanSymbol("8703"),
+                    TradeItSDKHolder.getSymbolProvider().getJapanSymbol(symbol),
                     TradeItSDKHolder.getBuyingPower())
         }
         return orderForm
@@ -49,18 +54,6 @@ class OrderInputViewModel : ViewModel() {
         }
     }
 
-    fun init(symbol: String?) {
-        // TODO need a cleaner way to initialize the OrderForm
-        if (symbol != null) {
-            if (!this::orderForm.isInitialized || (this::orderForm.isInitialized && symbol != orderForm.value?.symbol?.symbol)) {
-                orderForm = MutableLiveData()
-                orderForm.value = OrderForm(
-                        TradeItSDKHolder.getSymbolProvider().getJapanSymbol(symbol),
-                        TradeItSDKHolder.getBuyingPower())
-            }
-        }
-    }
-
     fun setMarketOrder() {
         orderForm.value = orderForm.value?.apply {
             orderInfo = orderInfo.copy(type = OrderType.MARKET, limitPrice = symbol.price)
@@ -74,6 +67,14 @@ class OrderInputViewModel : ViewModel() {
     }
 }
 
+class OrderInputViewModelFactory(private val symbol: String) : ViewModelProvider.NewInstanceFactory() {
+    override fun <T : ViewModel?> create(modelClass: Class<T>): T {
+        @Suppress("UNCHECKED_CAST")
+        return OrderInputViewModel(symbol) as T
+    }
+
+}
+
 class OrderForm(val symbol: JapanSymbol, val buyingPower: BuyingPower) {
     var orderInfo: OrderInfo = OrderInfo(
             quantity = symbol.lotSize,