fromDynamic static method

JsonDropdownButtonFormFieldBuilderModel fromDynamic(dynamic map, { Map<String, dynamic> args = const {}, JsonWidgetRegistry? registry, })

Builds the builder from a Map-like dynamic structure. This expects the JSON format to be of the following structure:

{
  "alignment": "<Alignment>",
  "autofocus": "<bool>",
  "autovalidateMode": "<AutovalidateMode>",
  "borderRadius": "<BorderRadius>",
  "decoration": "<InputDecorationDecoder>",
  "disabledHint": "<JsonWidgetData>",
  "dropdownColor": "<Color>",
  "elevation": "<int>",
  "enabled": "<bool>",
  "focusColor": "<Color>",
  "focusNode": "<FocusNode>",
  "hint": "<JsonWidgetData>",
  "icon": "<JsonWidgetData>",
  "items": "<List<String>> || <Map<String, dynamic>>",
  "iconDisabledColor": "<Color>",
  "iconEnabledColor": "<Color>",
  "iconSize": "<double>",
  "isDense": "<bool>",
  "isExpanded": "<bool>",
  "itemHeight": "<double>",
  "onChanged": "<ValueChanged>",
  "onSaved": "<FormFieldSetter>",
  "onTap": "<VoidCallback>",
  "selectedItemBuilder": "<DropdownButtonBuilder> || <JsonWidgetData>",
  "validators": "<List<ValueValidator>>",
  "style": "<TextStyle>",
  "value": "<dynamic>"
}

As a note, the FocusNode, ValueChanged, FormFieldSetter, and VoidCallback objects cannot be decoded via JSON. Instead, the only way to bind those values to the builder is to use a function or a variable reference via the JsonWidgetRegistry.

The selectedItemBuilder can be a DropdownButtonBuilder or JsonWidgetData. The DropdownButtonBuilder cannot be decoded via JSON and would have to be bound via the JsonWidgetRegistry. If a JsonWidgetData object is used then the item's display will be bound to the dropdown_item_display variable on the registry and the item's value will be bound to dropdown_item_value. This way the widget can associate properties to those two keys for proper rendering.

The items can be either a string array where the string will be used for both the display and the value or a map of strings to values where the key will be used as the display and the value will be the internal dropdown value.

See also:

• buildCustom
• InputDecorationDecoder.fromDynamic
• JsonWidgetData.fromDynamic
• ThemeDecoder.decodeAutovalidateMode
• ThemeDecoder.decodeColor
• ThemeDecoder.decodeTextStyle
• Validator

Implementation

static JsonDropdownButtonFormFieldBuilderModel fromDynamic(
  dynamic map, {
  Map<String, dynamic> args = const {},
  JsonWidgetRegistry? registry,
}) {
  final result = maybeFromDynamic(
    map,
    args: args,
    registry: registry,
  );

  if (result == null) {
    throw Exception(
      '[JsonDropdownButtonFormFieldBuilder]: requested to parse from dynamic, but the input is null.',
    );
  }

  return result;
}