Clarified access code requirement. Closes #17

Author: wilburx9

README.md

@@ -40,7 +40,7 @@ There are two ways of making payment with the plugin.
  reference. Pass an `accessCode` only when you have
  [initialized the transaction](https://developers.paystack.co/reference#initialize-a-transaction)
  from your backend. Otherwise, pass a `reference`.
-
+ 
 
  ```dart
  Charge charge = Charge()
@@ -50,10 +50,14 @@ There are two ways of making payment with the plugin.
        ..email = '[email protected]';
      CheckoutResponse response = await PaystackPlugin.checkout(
        context context,
+       method: CheckoutMethod.card, // Defaults to CheckoutMethod.selectable
        charge: charge,
      );
  ```
 
+Please, note that an `accessCode` is required if the method is
+`CheckoutMethod.bank` or `CheckoutMethod.selectable`.
+
  `PaystackPlugin.checkout()` returns the state and details of the
  payment in an instance of `CheckoutResponse` .
 

example/lib/main.dart

@@ -128,7 +128,7 @@ class _HomePageState extends State<HomePage> {
                           border: const UnderlineInputBorder(),
                           labelText: 'Expiry Month',
                         ),
-                        onSaved: (String value) => _expiryMonth = _toInt(value),
+                        onSaved: (String value) => _expiryMonth = int.tryParse(value),
                       ),
                     ),
                     _horizontalSizeBox,
@@ -138,7 +138,7 @@ class _HomePageState extends State<HomePage> {
                           border: const UnderlineInputBorder(),
                           labelText: 'Expiry Year',
                         ),
-                        onSaved: (String value) => _expiryYear = _toInt(value),
+                        onSaved: (String value) => _expiryYear = int.tryParse(value),
                       ),
                     )
                   ],
@@ -434,16 +434,6 @@ class _HomePageState extends State<HomePage> {
   }
 }
 
-int _toInt(String source) {
-  int value;
-  try {
-    return int.parse(source);
-  } catch (e) {
-    print('Error occured while parsing $value to int. Error: $e');
-  }
-  return value;
-}
-
 var banks = ['Selectable', 'Bank', 'Card'];
 
 CheckoutMethod _parseStringToMethod(String string) {

lib/src/common/paystack.dart

@@ -115,27 +115,26 @@ class PaystackPlugin {
   /// Make payment using Paystack's checkout form. The plugin will handle the whole
   /// processes involved.
   ///
-  /// [context] - the widgets BuildContext
+  /// [context] - the widget's BuildContext
+  ///
+  /// [charge] - the charge object.
   ///
-  /// [charge] - the charge object. You must pass the amount (in kobo) to it. If you
-  /// want to use CheckoutMethod.card/CheckoutMethod.selectable, you must also
-  /// pass either an  access code or payment reference to the charge object.
+  /// [onSuccess] - Called when the payment completes successfully
+  ///
+  /// [onValidated] - Called when the payment completes with an unrecoverable error
+  ///
+  /// [method] - The payment method to use(card, bank). It defaults to
+  /// [CheckoutMethod.selectable] to allow the user to select. For [CheckoutMethod.bank]
+  ///  or [CheckoutMethod.selectable], it is
+  /// required that you supply an access code to the [Charge] object passed to [charge].
+  /// For [CheckoutMethod.card], though not recommended, passing a reference to the
+  /// [Charge] object will do just fine.
   ///
   /// Notes:
   ///
-  /// * When you pass an  access code, the plugin won't
-  /// initialize the transaction and payment is made immediately
-  /// * When you pass the reference, the plugin will initialize the transaction
-  /// (via https://api.paystack.co/transaction/initialize) with the passed reference.
   /// * You can also pass the [PaymentCard] object and we'll use it to prepopulate the
   /// card  fields if card payment is being used
   ///
-  /// [onSuccess] - Called when the payment completes successfully
-  ///
-  /// [onValidated] - Called when the payment completes with an unrecoverable error
-  ///
-  /// [method] - The payment payment method to use(card, bank). It defaults to
-  /// [CheckoutMethod.selectable] to allow the user to select
   static Future<CheckoutResponse> checkout(
     BuildContext context, {
     @required Charge charge,

lib/src/widgets/checkout/checkout_widget.dart

@@ -31,7 +31,6 @@ class CheckoutWidget extends StatefulWidget {
 
 class _CheckoutWidgetState extends BaseState<CheckoutWidget>
     with TickerProviderStateMixin {
-  final _scaffoldKey = new GlobalKey<ScaffoldState>();
   static const tabBorderRadius = BorderRadius.all(Radius.circular(4.0));
   final Charge _charge;
   var _currentIndex = 0;
@@ -76,7 +75,6 @@ class _CheckoutWidgetState extends BaseState<CheckoutWidget>
   @override
   Widget buildChild(BuildContext context) {
     return new CustomAlertDialog(
-      key: _scaffoldKey,
       expanded: true,
       fullscreen: widget.fullscreen,
       titlePadding: EdgeInsets.all(0.0),
@@ -98,7 +96,7 @@ class _CheckoutWidgetState extends BaseState<CheckoutWidget>
   }
 
   Widget _buildTitle() {
-    var amountAndAmount = new Column(
+    var emailAndAmount = new Column(
       crossAxisAlignment: CrossAxisAlignment.end,
       children: <Widget>[
         _charge.email != null
@@ -193,7 +191,7 @@ class _CheckoutWidgetState extends BaseState<CheckoutWidget>
               new SizedBox(
                 width: 50.0,
               ),
-              new Expanded(child: amountAndAmount),
+              new Expanded(child: emailAndAmount),
             ],
           ),
         ),