Notify

A notify operation starts a transaction. Such operation outputs one or more fields to SPARKL.

Example XML code Notes

<notify 
  name="myNotify"  
  service="Sequencer"  
  clients="Expr"  
  fields="PING">  
  <prop 
    name="expr.auto"    
    interval="5s"    
    count="4"/>    
</notify>
Depending on its client service, a notify can have various properties and triggering conditions.

For example, myNotify is fired every 5 seconds for a total of 4 times, once Expr is started.

Attributes

A notify operation must have a name, a service that implements it, and some fields the operation outputs. Optionally, one or more client services can be specified on the notify that can trigger it.

name

The name of the component. Other components use this name to reference the component.

service

The service that implements the operation. The implementing service is referenced by its name.

clients

A space-separated list of services that can trigger the operation, thus starting a transaction. The services are referenced by name.

fields

A space-separated list of fields received or output by the operation subject. Depending on the type of operation, they can be input or output fields. The fields are referenced by their name.

Children

Depending on the service and client specified for the notify, the operation can have one or more properties for additional functionality or triggering conditions.

prop

A property defined for the component. For example, a Python or Erlang script. Most properties are specific to a SPARKL extension.