allex_servicecontainerservice

ServiceContainerService

This is a specialization of DataService

How it works

The service User has a spawn method.

Once you acquire a Sink to a service User, issue sink.call('spawn',...) in order to spawn a new sub-Service on the ServiceContainerService instance.

You need to specialize

ServiceContainerService is an abstract service. It provides no means to actually spawn a sub-Service.

However, it has all the methods to handle a sink to a newly instantiated sub-Service:

• the new sink will be put in the subservices map of the ServiceContainerService instance
• a new record describing the new sub-Service will be created in the ServiceContainerService data
• the record that describes the sub-Service will be updated whenever the sub-Service instance changes its state (provided that the state field is related to the Record of the ServiceContainerService)

Therefore, one should follow the dataStream (the 'd' Channel on the acquired Sink to ServiceContainerService) in order to obtain information on all contained sub-Services

How to specialize

1. Inherit from allex_dataservice
2. Define a storagedescriptor in storagedescriptor.js (especially the structure of the describing Record for data)
3. Write the acquireSink method on the service User (in users/serviceusercreator.js), because it will be called, but there is no generic implementation in ServiceContainerService.

Further tweaks

1. All sub-Services will be mapped in the subservices according to the instancename field of the property hash provided to the spawn method of the service User. You can change this behavior by overriding the _instanceNameFromRecord method of the service User.