getDropdownData method

Future<List<Map<String, String>>> getDropdownData({ required String entity, required String valueField, required String displayField, String? filterByField, String? filterValue, })

Fetch dropdown data from a Dynamics 365 entity.

Parameters: entity - The target data entity name (e.g., Customers, Items). valueField - The field name to be used as the unique key (e.g., "CustomerAccount"). displayField - The field name to be shown in the dropdown (e.g., "Name"). filterByField - (Optional) A field name used for filtering results. filterValue - (Optional) The value to filter by.

Returns: A List<Map<String, String>> where each map contains:

• "key" : the unique identifier of the record.
• "value" : the display name of the record.

Notes:

• Removes duplicates by converting the list to a Set, then back to a List.
• Throws an exception if the API request fails.
• Requires a valid access token from getAccessToken().

Implementation

Future<List<Map<String, String>>> getDropdownData({
  required String entity,
  required String valueField,
  required String displayField,
  String? filterByField,
  String? filterValue,
}) async {
  final token = await getAccessToken();
  if (token == null) return [];

  final uri = (filterByField != null &&
      filterByField.isNotEmpty &&
      filterValue != null &&
      filterValue.isNotEmpty)
      ? Uri.parse(
      "$resource/data/$entity?\$filter=$filterByField eq '$filterValue'")
      : Uri.parse("$resource/data/$entity");

  try {
    final response = await http.get(
      uri,
      headers: {
        'Authorization': 'Bearer $token',
        'Accept': 'application/json',
      },
    );

    if (response.statusCode == 200) {
      final data = jsonDecode(response.body);
      final entities = data['value'] as List;

      return entities
          .map<Map<String, String>>((e) {
        final key = e[valueField]?.toString() ?? '';
        final name = e[displayField]?.toString() ?? '';
        return {"key": key, "value": name};
      })
          .toSet()
          .toList();
    } else {
      throw Exception(
        '❌ Failed to fetch $entity: ${response.statusCode}\n${response
            .body}',
      );
    }
  } catch (e) {
    print('❗ Exception during getDropdownData: $e');
    rethrow;
  }
}