Deregister field key when corresponding widget is removed from widget tree

Author: danvick

CHANGELOG.md

@@ -1,3 +1,6 @@
+## [3.0.0-beta.10] - 20-April-2019
+* Unregister field from `Formbuilder` when its dispose method is called. Avoids assertion fail when re-added back to the widget tree
+
 ## [3.0.0-beta.9] - 15-April-2019
 * Added property `fields` to FormBuilder, gives access to the current state of each field through a Map of `GlobalKey<FormFieldState<dynamic>>`s. 
 This gives us access to the underlying FormField which in turn allows us: 

README.md

@@ -292,12 +292,13 @@ FormBuilderTextField(
 
 ## CREDITS
 This package is dependent on the following packages and plugins:
-* [flutter_typeahead](https://pub.dartlang.org/packages/flutter_typeahead) by [https://github.com/AbdulRahmanAlHamali](https://github.com/AbdulRahmanAlHamali)
-* [sy_flutter_widgets]((https://pub.dartlang.org/packages/sy_flutter_widgets)) by [Li Shuhao](https://github.com/lishuhao)
+* [flutter_typeahead](https://pub.dartlang.org/packages/flutter_typeahead) by [AbdulRahmanAlHamali](https://github.com/AbdulRahmanAlHamali)
+* [sy_flutter_widgets](https://pub.dartlang.org/packages/sy_flutter_widgets) by [Li Shuhao](https://github.com/lishuhao)
 * [datetime_picker_formfield](https://pub.dartlang.org/packages/datetime_picker_formfield) by [Jacob Phillips](https://github.com/jifalops)
-* [flutter_chips_input](https://pub.dartlang.org/packages/flutter_chips_input) by [Yours trully :)](https://github.com/danvick)
-* [intl](https://pub.dartlang.org/packages/intl)
+* [validators](https://pub.dartlang.org/packages/validators) by [dart-league](https://github.com/dart-league)
+* [intl](https://pub.dartlang.org/packages/intl) - Dart Package
 * The SignaturePad is based on [signature](https://pub.dartlang.org/packages/signature) by [4Q s.r.o.](https://github.com/4Q-s-r-o) with some minor improvements to fit our usage
+* [flutter_chips_input](https://pub.dartlang.org/packages/flutter_chips_input) by [Yours trully :)](https://github.com/danvick)
 
 ## TODO: 
 ### Improvements

lib/src/fields/form_builder_checkbox.dart

@@ -31,18 +31,20 @@ class FormBuilderCheckbox extends StatefulWidget {
 class _FormBuilderCheckboxState extends State<FormBuilderCheckbox> {
   bool _readonly = false;
   final GlobalKey<FormFieldState> _fieldKey = GlobalKey<FormFieldState>();
+  FormBuilderState _formState;
 
   @override
   void initState() {
-    registerFieldKey();
-    _readonly =
-        (FormBuilder.of(context)?.readonly == true) ? true : widget.readonly;
+    _formState = FormBuilder.of(context);
+    _formState?.registerFieldKey(widget.attribute, _fieldKey);
+    _readonly = (_formState?.readonly == true) ? true : widget.readonly;
     super.initState();
   }
 
-  registerFieldKey() {
-    if (FormBuilder.of(context) != null)
-      FormBuilder.of(context).registerFieldKey(widget.attribute, _fieldKey);
+  @override
+  void dispose() {
+    _formState?.unregisterFieldKey(widget.attribute);
+    super.dispose();
   }
 
   @override
@@ -63,7 +65,7 @@ class _FormBuilderCheckboxState extends State<FormBuilderCheckbox> {
           FormBuilder.of(context)
               ?.setAttributeValue(widget.attribute, transformed);
         } else
-          FormBuilder.of(context)?.setAttributeValue(widget.attribute, val);
+          _formState?.setAttributeValue(widget.attribute, val);
       },
       builder: (FormFieldState<dynamic> field) {
         return InputDecorator(

lib/src/fields/form_builder_checkbox_list.dart

@@ -32,18 +32,20 @@ class FormBuilderCheckboxList extends StatefulWidget {
 class _FormBuilderCheckboxListState extends State<FormBuilderCheckboxList> {
   bool _readonly = false;
   final GlobalKey<FormFieldState> _fieldKey = GlobalKey<FormFieldState>();
+  FormBuilderState _formState;
 
   @override
   void initState() {
-    registerFieldKey();
-    _readonly =
-        (FormBuilder.of(context)?.readonly == true) ? true : widget.readonly;
+    _formState = FormBuilder.of(context);
+    _formState?.registerFieldKey(widget.attribute, _fieldKey);
+    _readonly = (_formState?.readonly == true) ? true : widget.readonly;
     super.initState();
   }
 
-  registerFieldKey() {
-    if (FormBuilder.of(context) != null)
-      FormBuilder.of(context).registerFieldKey(widget.attribute, _fieldKey);
+  @override
+  void dispose() {
+    _formState?.unregisterFieldKey(widget.attribute);
+    super.dispose();
   }
 
   @override
@@ -64,7 +66,7 @@ class _FormBuilderCheckboxListState extends State<FormBuilderCheckboxList> {
             FormBuilder.of(context)
                 ?.setAttributeValue(widget.attribute, transformed);
           } else
-            FormBuilder.of(context)?.setAttributeValue(widget.attribute, val);
+            _formState?.setAttributeValue(widget.attribute, val);
         },
         builder: (FormFieldState<dynamic> field) {
           List<Widget> checkboxList = [];

lib/src/fields/form_builder_chips_input.dart

@@ -41,18 +41,20 @@ class FormBuilderChipsInput<T> extends StatefulWidget {
 class _FormBuilderChipsInputState extends State<FormBuilderChipsInput> {
   bool _readonly = false;
   final GlobalKey<FormFieldState> _fieldKey = GlobalKey<FormFieldState>();
+  FormBuilderState _formState;
 
   @override
   void initState() {
-    registerFieldKey();
-    _readonly =
-        (FormBuilder.of(context)?.readonly == true) ? true : widget.readonly;
+    _formState = FormBuilder.of(context);
+    _formState?.registerFieldKey(widget.attribute, _fieldKey);
+    _readonly = (_formState?.readonly == true) ? true : widget.readonly;
     super.initState();
   }
 
-  registerFieldKey() {
-    if (FormBuilder.of(context) != null)
-      FormBuilder.of(context).registerFieldKey(widget.attribute, _fieldKey);
+  @override
+  void dispose() {
+    _formState?.unregisterFieldKey(widget.attribute);
+    super.dispose();
   }
 
   @override
@@ -62,7 +64,7 @@ class _FormBuilderChipsInputState extends State<FormBuilderChipsInput> {
       child: FormField(
         key: _fieldKey,
         enabled: !_readonly,
-        initialValue: widget.initialValue,
+        initialValue: widget.initialValue ?? [],
         validator: (val) {
           for (int i = 0; i < widget.validators.length; i++) {
             if (widget.validators[i](val) != null)
@@ -75,7 +77,7 @@ class _FormBuilderChipsInputState extends State<FormBuilderChipsInput> {
             FormBuilder.of(context)
                 ?.setAttributeValue(widget.attribute, transformed);
           } else
-            FormBuilder.of(context)?.setAttributeValue(widget.attribute, val);
+            _formState?.setAttributeValue(widget.attribute, val);
         },
         builder: (FormFieldState<dynamic> field) {
           return ChipsInput(

lib/src/fields/form_builder_date_time_picker.dart

@@ -141,6 +141,7 @@ class FormBuilderDateTimePicker extends StatefulWidget {
 class _FormBuilderDateTimePickerState extends State<FormBuilderDateTimePicker> {
   bool _readonly = false;
   final GlobalKey<FormFieldState> _fieldKey = GlobalKey<FormFieldState>();
+  FormBuilderState _formState;
 
   final _dateTimeFormats = {
     InputType.both: DateFormat("EEEE, MMMM d, yyyy 'at' h:mma"),
@@ -150,15 +151,16 @@ class _FormBuilderDateTimePickerState extends State<FormBuilderDateTimePicker> {
 
   @override
   void initState() {
-    registerFieldKey();
-    _readonly =
-        (FormBuilder.of(context)?.readonly == true) ? true : widget.readonly;
+    _formState = FormBuilder.of(context);
+    _formState?.registerFieldKey(widget.attribute, _fieldKey);
+    _readonly = (_formState?.readonly == true) ? true : widget.readonly;
     super.initState();
   }
 
-  registerFieldKey() {
-    if (FormBuilder.of(context) != null)
-      FormBuilder.of(context).registerFieldKey(widget.attribute, _fieldKey);
+  @override
+  void dispose() {
+    _formState?.unregisterFieldKey(widget.attribute);
+    super.dispose();
   }
 
   @override
@@ -182,7 +184,7 @@ class _FormBuilderDateTimePickerState extends State<FormBuilderDateTimePicker> {
           FormBuilder.of(context)
               ?.setAttributeValue(widget.attribute, transformed);
         } else
-          FormBuilder.of(context)?.setAttributeValue(widget.attribute, val);
+          _formState?.setAttributeValue(widget.attribute, val);
       },
       validator: (val) {
         for (int i = 0; i < widget.validators.length; i++) {

lib/src/fields/form_builder_dropdown.dart

@@ -45,18 +45,20 @@ class FormBuilderDropdown extends StatefulWidget {
 class _FormBuilderDropdownState extends State<FormBuilderDropdown> {
   bool _readonly = false;
   final GlobalKey<FormFieldState> _fieldKey = GlobalKey<FormFieldState>();
+  FormBuilderState _formState;
 
   @override
   void initState() {
-    registerFieldKey();
-    _readonly =
-        (FormBuilder.of(context)?.readonly == true) ? true : widget.readonly;
+    _formState = FormBuilder.of(context);
+    _formState?.registerFieldKey(widget.attribute, _fieldKey);
+    _readonly = (_formState?.readonly == true) ? true : widget.readonly;
     super.initState();
   }
 
-  registerFieldKey() {
-    if (FormBuilder.of(context) != null)
-      FormBuilder.of(context).registerFieldKey(widget.attribute, _fieldKey);
+  @override
+  void dispose() {
+    _formState?.unregisterFieldKey(widget.attribute);
+    super.dispose();
   }
 
   @override
@@ -77,7 +79,7 @@ class _FormBuilderDropdownState extends State<FormBuilderDropdown> {
           FormBuilder.of(context)
               ?.setAttributeValue(widget.attribute, transformed);
         } else
-          FormBuilder.of(context)?.setAttributeValue(widget.attribute, val);
+          _formState?.setAttributeValue(widget.attribute, val);
       },
       builder: (FormFieldState<dynamic> field) {
         return InputDecorator(

lib/src/fields/form_builder_radio.dart

@@ -31,18 +31,20 @@ class FormBuilderRadio extends StatefulWidget {
 class _FormBuilderRadioState extends State<FormBuilderRadio> {
   bool _readonly = false;
   final GlobalKey<FormFieldState> _fieldKey = GlobalKey<FormFieldState>();
+  FormBuilderState _formState;
 
   @override
   void initState() {
-    registerFieldKey();
-    _readonly =
-        (FormBuilder.of(context)?.readonly == true) ? true : widget.readonly;
+    _formState = FormBuilder.of(context);
+    _formState?.registerFieldKey(widget.attribute, _fieldKey);
+    _readonly = (_formState?.readonly == true) ? true : widget.readonly;
     super.initState();
   }
 
-  registerFieldKey() {
-    if (FormBuilder.of(context) != null)
-      FormBuilder.of(context).registerFieldKey(widget.attribute, _fieldKey);
+  @override
+  void dispose() {
+    _formState?.unregisterFieldKey(widget.attribute);
+    super.dispose();
   }
 
   @override
@@ -63,7 +65,7 @@ class _FormBuilderRadioState extends State<FormBuilderRadio> {
           FormBuilder.of(context)
               ?.setAttributeValue(widget.attribute, transformed);
         } else
-          FormBuilder.of(context)?.setAttributeValue(widget.attribute, val);
+          _formState?.setAttributeValue(widget.attribute, val);
       },
       builder: (FormFieldState<dynamic> field) {
         List<Widget> radioList = [];

lib/src/fields/form_builder_rate.dart

@@ -36,18 +36,20 @@ class FormBuilderRate extends StatefulWidget {
 class _FormBuilderRateState extends State<FormBuilderRate> {
   bool _readonly = false;
   final GlobalKey<FormFieldState> _fieldKey = GlobalKey<FormFieldState>();
+  FormBuilderState _formState;
 
   @override
   void initState() {
-    registerFieldKey();
-    _readonly =
-        (FormBuilder.of(context)?.readonly == true) ? true : widget.readonly;
+    _formState = FormBuilder.of(context);
+    _formState?.registerFieldKey(widget.attribute, _fieldKey);
+    _readonly = (_formState?.readonly == true) ? true : widget.readonly;
     super.initState();
   }
 
-  registerFieldKey() {
-    if (FormBuilder.of(context) != null)
-      FormBuilder.of(context).registerFieldKey(widget.attribute, _fieldKey);
+  @override
+  void dispose() {
+    _formState?.unregisterFieldKey(widget.attribute);
+    super.dispose();
   }
 
   @override
@@ -68,7 +70,7 @@ class _FormBuilderRateState extends State<FormBuilderRate> {
           FormBuilder.of(context)
               ?.setAttributeValue(widget.attribute, transformed);
         } else
-          FormBuilder.of(context)?.setAttributeValue(widget.attribute, val);
+          _formState?.setAttributeValue(widget.attribute, val);
       },
       builder: (FormFieldState<dynamic> field) {
         return InputDecorator(

lib/src/fields/form_builder_segmented_control.dart

@@ -34,18 +34,20 @@ class _FormBuilderSegmentedControlState
     extends State<FormBuilderSegmentedControl> {
   bool _readonly = false;
   final GlobalKey<FormFieldState> _fieldKey = GlobalKey<FormFieldState>();
+  FormBuilderState _formState;
 
   @override
   void initState() {
-    registerFieldKey();
-    _readonly =
-        (FormBuilder.of(context)?.readonly == true) ? true : widget.readonly;
+    _formState = FormBuilder.of(context);
+    _formState?.registerFieldKey(widget.attribute, _fieldKey);
+    _readonly = (_formState?.readonly == true) ? true : widget.readonly;
     super.initState();
   }
 
-  registerFieldKey() {
-    if (FormBuilder.of(context) != null)
-      FormBuilder.of(context).registerFieldKey(widget.attribute, _fieldKey);
+  @override
+  void dispose() {
+    _formState?.unregisterFieldKey(widget.attribute);
+    super.dispose();
   }
 
   @override
@@ -66,7 +68,7 @@ class _FormBuilderSegmentedControlState
           FormBuilder.of(context)
               ?.setAttributeValue(widget.attribute, transformed);
         } else
-          FormBuilder.of(context)?.setAttributeValue(widget.attribute, val);
+          _formState?.setAttributeValue(widget.attribute, val);
       },
       builder: (FormFieldState<dynamic> field) {
         return InputDecorator(