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Development of FEWS Adapter

The model adapter as described in this manual provides the interface between a so-called model and the Delft-FEWS system. It enables FEWS to run such a model, thus providing the essential forecasting functionality. For each particular FEWS application applying a model, however, some aspects of this system have to be configured by the user in order for the system to work correctly. To achieve this, it is useful that the user has at least some basic understanding of the relation between Delft-FEWS, the model adapter and the forecasting model. In this section, a brief overview of this relation is provided. For more information, the user is referred to the FEWS manual: General Adapter.

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External Modules and their adapters can be written in any programming language. However, in case Java is used, they have to implement the interface ModuleAdapterRunnable. Modules and module adapters can only communicate with the General Adapter via the Published Interface. The only 2 means to exchange information with the General Adapter are:

• The return code indicating the result of an execution. A return code of 1 indicates a successful execution, all other codes other than 0 execution failure.A diagnostic file written in the Published Interface format. If such a diagnostic file is available the General Adapter will read it and write corresponding logs to the FEWS system.
• The return code indicating the result of an execution.

  return code	meaning
  0	graceful failure - read message
  1	successful execution
  all other	non graceful failure

Modules and their adapters cannot use exception or event handling as a means to communicate with the General Adapter.

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