A step definition for processing the back-end data collection.
A fetch server exchange step defines how
information about the
system’s data is processed. This definition references a step
definition within the same module. This step has access to
information about the target collection, as well as to any data
captured in fetch properties. A server exchange step can be
defined to execute once or iteratively, and can return data for
an object collection.
server exchange step definition is intended to perform one of two
tasks within the exchange data model. First, it should compare information
provided by the client exchange steps concerning which object instances
the Client currently has and when they were retrieved to information
in the back end system about when that same data was last modified
or added. Second, it can then retrieve the data needed by the Client
based on the differences found during this comparison. These tasks
are normally accomplished by separate server exchange steps. Alternately
or in addition to these definitions, the object read steps defined
in the object type targeted by the fetch may retrieve data for the
Server Exchange Step Attributes
- Step: This
attribute references the step definition within the same module
to run as a server exchange step for the parent fetch.
- Run: This attribute specifies how to run the server exchange
step during a single transmit. This may be set to one of the following
- Run one Time: This setting will run the server
exchange step a single time for the fetch processing. This setting
assumes the step needs to be executed only once to return the data
for all object instances to be added or replaced during synchronization, or
the step being executed is not returning data but rather is being
run in support of synchronization.
- Run Once per Object: This setting will execute the server
exchange step once for each object instance in the collection that
is being synchronized. This includes both those object instances
sent by the Client to the Server, as well as any that may have been
added by previous fetch steps.
- Read Into: This attribute specifies the child or descendent
object collection property of the target collection into which the
data returned by the step should be read. This attribute has a default
setting of “None”. This default means the data will not be read
into a child collection but will instead be used to create object
instances of the target collection. Other valid options for this
attribute are any child collection properties of the target collection,
or any descendent collections (e.g. collections within collections).