smartstruct 1.4.0 smartstruct: ^1.4.0 copied to clipboard
smartstruct - A dart bean mapper annotation processor - the easy nullsafe way!
Simple Mapping #
// dogmapper.dart
class Dog {
final String breed;
final int age;
final String name;
Dog(this.breed, this.age, this.name);
}
class DogModel {
final String breed;
final int age;
final String name;
DogModel(this.breed, this.age, this.name);
}
To generate a mapper for these two beans, you need to create a mapper interface.
import 'package:smartstruct/smartstruct.dart';
// dog.mapper.dart
part 'dogmapper.mapper.g.dart';
@Mapper()
abstract class DogMapper {
Dog fromModel(DogModel model);
}
Explicit Field Mapping #
If some fields do not match each other, you can add a Mapping Annotation on the method level, to change the behaviour of certain mappings.
class Dog {
final String name;
Dog(this.name);
}
class DogModel {
final String dogName;
DogModel(this.dogName);
}
// dogmapper.dart
import 'package:smartstruct/smartstruct.dart';
part 'dogmapper.mapper.g.dart';
@Mapper()
class DogMapper {
@Mapping(source: 'dogName', target: 'name')
Dog fromModel(DogModel model);
}
In this case, the field dogName of DogModel will be mapped to the field name of the resulting Dog
// dogmapper.mapper.g.dart
class DogMapperImpl extends DogMapper {
@override
Dog fromModel(DogModel model) {
Dog dog = Dog(model.dogName);
return dog;
}
}
Function Mapping #
The source attribute can also be a Function. This Function will then be called with the Source Parameter of the mapper method as a parameter.
class Dog {
final String name;
final String breed;
Dog(this.name, this.breed);
}
class DogModel {
final String name;
DogModel(this.name);
}
@Mapper()
class DogMapper {
static String randomBreed(DogModel model) => 'some random breed';
@Mapping(source: randomBreed, target: 'breed')
Dog fromModel(DogModel model);
}
Will generate the following Mapper.
class DogMapperImpl extends DogMapper {
@override
Dog fromModel(DogModel model) {
Dog dog = Dog(model.dogName, DogMapper.randomBreed(model));
return dog;
}
}
Nested Bean Mapping #
Nested beans can be mapped, by defining an additional mapper method for the nested bean.
class NestedTarget {
final SubNestedTarget subNested;
NestedTarget(this.subNested);
}
class SubNestedTarget {
final String myProperty;
SubNestedTarget(this.myProperty);
}
class NestedSource {
final SubNestedSource subNested;
NestedSource(this.subNested);
}
class SubNestedSource {
final String myProperty;
SubNestedSource(this.myProperty);
}
// nestedmapper.dart
import 'package:smartstruct/smartstruct.dart';
part 'nested.mapper.g.dart';
@Mapper()
abstract class NestedMapper {
NestedTarget fromModel(NestedSource model);
SubNestedTarget fromSubClassModel(SubNestedSource model);
}
Will generate the mapper
// nestedmapper.mapper.g.dart
class NestedMapperImpl extends NestedMapper {
@override
NestedTarget fromModel(NestedSource model) {
final nestedtarget = NestedTarget(fromSubClassModel(model.subNested));
return nestedtarget;
}
@override
SubNestedTarget fromSubClassModel(SubNestedSource model) {
final subnestedtarget = SubNestedTarget(model.myProperty);
return subnestedtarget;
}
}
List Support #
Lists will be mapped as new instances of a list, with help of the map method.
class Source {
final List<int> intList;
final List<SourceEntry> entryList;
Source(this.intList, this.entryList);
}
class SourceEntry {
final String prop;
SourceEntry(this.prop);
}
class Target {
final List<int> intList;
final List<TargetEntry> entryList;
Target(this.intList, this.entryList);
}
class TargetEntry {
final String prop;
TargetEntry(this.prop);
}
@Mapper()
abstract class ListMapper {
Target fromSource(Source source);
TargetEntry fromSourceEntry(SourceEntry source);
}
Will generate the Mapper
class ListMapperImpl extends ListMapper {
@override
Target fromSource(Source source) {
final target = Target(
source.intList.map((e) => e).toList(),
source.entryList.map(fromSourceEntry).toList());
return target;
}
@override
TargetEntry fromSourceEntry(SourceEntry source) {
final targetentry = TargetEntry(source.prop);
return targetentry;
}
}
Injectable #
The Mapper can be made a lazy injectable singleton, by setting the argument useInjection to true, in the Mapper Interface. In this case you also need to add the injectable dependency, as described here. https://pub.dev/packages/injectable
Make sure, that in the Mapper File, you import the injectable dependency, before running the build_runner!
// dogmapper.dart
import 'package:smartstruct/smartstruct.dart';
import 'package:injectable/injectable.dart';
part 'dogmapper.mapper.g.dart';
@Mapper(useInjectable = true)
abstract class DogMapper {
Dog fromModel(DogModel model);
}
// dogmapper.mapper.g.dart
@LazySingleton(as: DogMapper)
class DogMapperImpl extends DogMapper {...}