Non Intrusive Serialization

This example shows how to do non intrusive serialization. This is useful for customizing the serialization of third party types.

module main;

import orange.serialization._;
import orange.serialization.archives._;

int i;

class Base
{
    int x;
}

class Foo
{
    private int a_;
    private int b_;

    // hide the instance variables behind properties.
    @property int a () { return a_; }
    @property int a (int a) { return a_ = a; }
    @property int b () { return b_; }
    @property int b (int b) { return b_ = b; }
}

// This method will be called when the this class is serialized.
// "foo" will be the object currently being serialized
// "serializer" will be the serializer performing the serialization process.
// "key" will be the key used to serialize "foo".
void toData (Foo foo, Serializer serializer, Serializer.Data key)
{
    // increment "i" just to show this method is called on serialization
    i++;

    // serialize the fields via properties
    serializer.serialize(foo.a, "a");
    serializer.serialize(foo.b, "b");

    // serializer the base class
    serializer.serializeBase(foo);
}

// This method will be called when the this class is deserialized.
void fromData (ref Foo foo, Serializer serializer, Serializer.Data key)
{
    // increment "i" just to show this method is called on deserialization
    i++;

    // deserialize the fields via properties
    foo.a = serializer.deserialize!(int)("a");
    foo.b = serializer.deserialize!(int)("b");

    // deserializer the base class
    serializer.deserializeBase(foo);
}

void main()
{
    auto archive = new XmlArchive!(char);
    auto serializer = new Serializer(archive);

    Serializer.registerSerializer!(Foo)(&toData);
    Serializer.registerDeserializer!(Foo)(&fromData);

    auto foo = new Foo;
    foo.a = 3;
    foo.b = 4;
    i = 3;

    serializer.serialize(foo);
    assert(i == 4);

    auto f = serializer.deserialize!(Foo)(archive.untypedData);
    assert(i == 5);
    assert(foo.a == f.a);
}