In this guide, we'll review two new built in transformers added in ShapeShift version 0.0.7, ImplicitMappingTransformer and ImplicitCollectionMappingTransformer.
ImplicitMappingTransformer
ImplicitMappingTransformer is used to transform subclasses mapped with ShapeShift. Lets look at the following example:
We have mapped Address class to its display class AddressDisplay.
@DefaultMappingTarget(AddressDisplay::class)
class Address {
@MappedField
var country: String? = null
@MappedField
var city: String? = null
@MappedField
var address: String? = null
}
class AddressDisplay {
var country: String? = null
var city: String? = null
var address: String? = null
}
@DefaultMappingTarget(AddressDisplay::class)
public class Address {
@MappedField
private String country;
@MappedField
private String city;
@MappedField
private String address;
// Getters and Setters...
}
public class AddressDisplay {
private String country;
private String city;
private String address;
// Getters and Setters...
}
We can use ShapeShift to map Address to AddressDisplay. But what we do if Address is a subclass? We use the ImplicitMappingTransformer.
@DefaultMappingTarget(UserDisplay::class)
class User {
@MappedField
var name: String? = null
@MappedField(transformer = ImplicitMappingTransformer::class)
var address: Address? = null
}
class UserDisplay {
var name: String? = null
var address: AddressDisplay? = null
}
@DefaultMappingTarget(UserDisplay::class)
public class User {
@MappedField
private String name;
@MappedField(transformer = ImplicitMappingTransformer.class)
private Address address;
// Getters and Setters...
}
public class UserDisplay {
private String name;
private AddressDisplay address;
// Getters and Setters...
}
The ImplicitMappingTransformer uses the ShapeShift instance internally to map Address to AddressDisplay.
ImplicitCollectionMappingTransformer
ImplicitCollectionMappingTransformer has the same job as ImplicitMappingTransformer but for collections.
@DefaultMappingTarget(UserDisplay::class)
class User {
@MappedField
var name: String? = null
@MappedField(transformer = ImplicitCollectionMappingTransformer::class)
var addresses: List<Address>? = null
}
class UserDisplay {
var name: String? = null
var addresses: List<AddressDisplay>? = null
}
@DefaultMappingTarget(UserDisplay::class)
public class User {
@MappedField
private String name;
@MappedField(transformer = ImplicitCollectionMappingTransformer.class)
private List<Address> addresses;
// Getters and Setters...
}
public class UserDisplay {
private String name;
private List<AddressDisplay> addresses;
// Getters and Setters...
}
