com.prosyst.mprm.backend.rules.spi.io

Interface ScriptSerializable

public interface ScriptSerializable

Should be implemented by objects, part of the Script Services APIs that need to be serialized and deserialized, but deserializing/restoring of objects need a context reference to the runtime system.

1. Example of object needing context reference to the runtime system: class MyObject { private Connection deviceConection; public void sendCommandToDevice(String command) { deviceConection.send(command); } } In this example, the object needs a connection to the device to be able to interpret the sendCommandToDevice method. Such a connection might not be possible to be instantiated in an empty constructor, but needs to be taken somehow from a the mPRM runtime. For this purpose, the Rule Engine supports a mechanism for delegating the serialization and deserialization of such objects to a dedicated services - ScriptSerializer-s, registered in the OSGi Service registry on the mPRM backend. To link a ScriptSerializable object to a ScriptSerializer service, the getScriptSerializerType() of the ScriptSerializable object must match the ScriptSerializer.SERIALIZER_TYPE registration property of the ScriptSerializer service.

2. When an object needs to be serialized/deserialized: Serialization/deserialization for groovu script objects is needed in the following cases:

when objects need to participate in groovy Closures representing groovy code that needs to be invoked after an asynchronous execution is finished. Example:
myObject = myScriptService.getMyObject(......); Closure c = {myObject.sendCommand("command-2")} myObject.sendCommand("command-1", c);
In these situations the Rule Engine stores Closures into until the time for their invocation is come. They even need to survive mPRM restarts. Writing the Closures into the database, intelligibly requires all references used within the Closures to be serialized and deserialized. event objects used for Functional Rule Triggers need to be transferred between mPRM backend hosts. Thus, such event objects need serialization/deserialization, too.

In case the serialized objects do not need context runtime reference, a supported way to do the serialization is to implement: java.io.Serializable, or com.prosyst.util.io.Externalizable.