Specification

f(x,y) where the implementation uses y':TRANSREPT(y)

Description

The state transreption pattern is effectively a dynamic 'compilation' performance optimization made possible by NetKernel's REST-like model. Very often a service will require configuration state to be supplied as an argument in order to perform a function (indeed this is the embodiment of Representational State Transfer (REST)). Often the configuration state is static or pseudo-static with respect to the lifetime of the application's data and generally the configuration information is supplied in a declarative serialization, such as XML.

It is inefficient to have to parse and/or otherwise process the config information in its declarative domain for each request for the same service with the same configuration.

The state transreption pattern can be used to dynamically transrept ('compile') the configuration state to an efficient Aspect with appropriately implemented fast information lookup methods. If the service source's its configuration argument and specifies that it requires the efficient Aspect then it can rely on the NetKernel infrastructure to dynamically perform the 'compilation' from the declarative form to the efficient Aspect form.

To implement this pattern all that is needed is for the developer to provide a custom efficient Aspect (object) and a registered Transreptor which is capable of converting the declarative form to the efficient Aspect form.

The resultant compiled configuration resource will be cached and so the transreption process occurs only once for all uses of the service.

Usage

This pattern occurs frequently and is used to by all the supplied library services which take configuration state - see for example HTTPBridge, sqlQuery etc.