JsonFileModel class abstract

JSON file-based persistence backend for Model.

Features:

  • Zero-config: one JSON file per model (users.json, posts.json)
  • Automatic UUID + timestamp handling
  • Constructor registration via migrate<T>()
  • Full CRUD with filtering (where, firstWhere)
  • Atomic file writes
  • Type-safe model instantiation

File Structure:

lib/src/storage/json_file_models/
  users.json
  posts.json
  ...

Example:

// Define model
class User extends Model {
  String name;
  String email;

  User({this.name = '', this.email = ''});

  @override
  Map<String, dynamic> toJson() => {'name': name, 'email': email};

  @override
  Map<String, dynamic> toMetaJson() => {
    'id': id,
    'uuid': uuid,
    'created_at': createdAt?.toIso8601String(),
    'updated_at': updatedAt?.toIso8601String(),
  };

  User.fromJson(Map<String, dynamic> json)
      : name = json['name'],
        email = json['email'],
        super.fromJson(json);
}

// Register constructor
JsonFileModel.migrate<User>((json) => User.fromJson(json));

// Use
final user = await JsonFileModel.create<User>({'name': 'John'});
final all = await JsonFileModel.index<User>();

Constructors

JsonFileModel()

Properties

hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Properties

dir → String
Base directory for JSON model files.
final
migrations → Map<Type, Function>
Public access to constructor registry (for migrations).
no setter

Static Methods

all<T extends Model>() → Future<List<T>>
Alias for index<T>().
count<T extends Model>() → Future<int>
Counts total records.
create<T extends Model>(Map<String, dynamic> json) → Future<T?>
Creates a new record from json.
delete<T extends Model>({required String uuid}) → Future<bool>
Deletes record by UUID.
deleteInstance<T extends Model>({required T instance}) → Future<bool>
Deletes instance by UUID.
exists<T extends Model>({required dynamic id}) → Future<bool>
Checks if record with id (UUID) exists.
find<T extends Model>({required String uuid}) → Future<T?>
Finds record by UUID.
findBy<T extends Model>({required String field, required dynamic value}) → Future<T?>
Finds first record where field == value.
firstWhere<T extends Model>({required String field, String comp = "==", dynamic value}) → Future<T?>
Returns first record matching where() condition.
index<T extends Model>() → Future<List<T>>
Retrieves all records of type T.
jsonFind<T extends Model>(String uuid) → Future<Map<String, dynamic>?>
Returns raw JSON record by UUID.
jsonIndex<T extends Model>() → Future<List<Map<String, dynamic>>>
Returns raw JSON records (no model instantiation).
migrate<T extends Model>({required T constructor(Map<String, dynamic>)}) → Future<void>
Registers a constructor for type T.
save<T extends Model>(T instance) → Future<bool>
Saves instance (create if new, update if exists).
saveInstance<T extends Model>({required T instance}) → Future<bool>
Saves instance.
truncate<T extends Model>() → Future<bool>
Empties the table file.
update<T extends Model>({required dynamic id, required String field, required dynamic value}) → Future<bool>
Updates a single field by UUID.
updateInstance<T extends Model>({required T instance, required Map<String, dynamic> withJson}) → Future<bool>
Updates instance with partial withJson.
where<T extends Model>({required String field, String comp = "==", dynamic value}) → Future<List<T>>
Filters records with comparison operators.