Models integration components reference

Overview

DecernsSDSS may use math models to calculate criteria values or generate new map layers. To make a particular model available to SDSS it is necessary to link it to models provider.

Models provider is an application which may handle requests from SDSS to particular models. DecernsSDSS can work with different models providers at the same time. Generally speaking, to link model to provider it is necessary to wrap model to web service and implement model adapter as well as model's web GUI. This work may be done only by developers. So there is no way to link any model with SDSS automatically. But there is an infrastructure which allows to link model(s) to SDSS using standard approach without rebuilding SDSS.

Each request to perform calculation is considered by models provider as a task. Tasks are managed by task manager and handled in asynchronous mode. Tasks can be saved to Data Base and loaded by request. It means that many calculation tasks at the same time may be executed and no live http connection required.

The main advantage of this architecture is that DecernsSDSS has not to implement models specific code and may use general approach to link with different models. Communication servlet and models manager are built-in to SDSS to make interaction with the available models. Communication servlet is responsible for interaction with models provider. Models manager is described in details in the next section of this cahpter.
MP Overview

Models manager

Models manager is used to manage calculation tasks and view results of calculations. To start calculation task select model from the list of available models and press "Run Model" button. Models GUI will be displayed and input model parameters have to be set before calculation. Running tasks are displayed in the tasks queue. Number of tasks which may be added to the queue is not limited. Default task name may be changed by double clicking an appropriate row in the queue with subsequent editing. Each task has status flag which indicates current state of the task (PROCESSING, COMPLETED, ERROR). To update status of the tasks in the queue press "Refresh" button. Tasks are processed by models provider in asynchronous mode. Thus, it is possible to start a task, save project and view results of calculation at any other time. To view selected model description, press "View Info" button. HTML page with detailed models description will be displayed.
Tasks

To view results of calculation select completed task and go to the "Results" page. Note: Results may be displayed only for the task which have status "COMPLETED". Results viewing page contains on the left side the list of calculated data (for the selected task) and area on the center for visualization results and information messages. Results may be presented as tables, diagrams and information layers. To view a particular result of calculation select the item in the list and press "Load" button (or just double-click the item). Tables and diagrams will be displayed on the central area of the results viewing page. Information layers will be loaded to GIS module and information message (success or error) will be displayed on the central area of the results viewing page.
Results

To close models manager dialog press "X" button on the dialog's caption or just press "Esc" button.