User's Guide to the GaeaVE Process Editor

The Process Editor allows users to examine the node and link structure of an existing process within Gaea, create new processes, either from scratch or as a modification of an existing process, or edit an existing process. Processes may also be executed for testing purposes from the Process Editor. The Process Editor uses a network description for a process, where nodes are either data objects or operators. The data objects are attributes of instantiations of data classes; thus an operator might work on the time field of one class instance and the image field of another.

Color is used for two purposes within the Process Editor. First, each instance of an input or output class is assigned a unique color, and the icons for all fields associated with a particular instance are either outlined or filled in that color. Also, each field type (which is an Abstract Data Type, or ADT) has a color associated with it. This is used for coloring buttons on each node to indicate what input and output ports for data and operators can be connected.

The Process Editor interface is divided into several regions. The large space at the bottom (called the Stage) is for constructing the nodes and links of the process. There are regions for selecting the data classes for all input and output for the process. Menus are provided of all currently available classes (new classes can be created using the

The following is the procedure to create a new process.

to Specify an input class, click on Input and select an item from the list of all classes.
to Specify the output class, click on Output and select an item from the list of all classes.
For our example, we select three input classes.
To Specify a process, we need to link data object attributes to operator inputs and operator outputs to either the inputs of other operators or to the attributes of our output object. First, select the attributes from the input classes which will be passed to operators by clicking on the hand-and-button button of one of the input class icons and chosing one attribute from the list at a time to put on stage.
To Instantiate (retrieve an instance of) an object, click on the ? button. Then specify the conditions of the query by typing in the desired values of one or more attributes.

If a data object which matches the specified conditions is found, the input class and all its attributes are shaded with the same border color.
Use the ADT list to select an operator to process the currently selected input data. Only operators capable of accepting this data type are listed. Use the right button on the ADT icon to select an operator,
Put the operator on the stage and click on the ports to link input data to it. The color of the ports indicates the type of data it is expecting. Only valid data types will be accepted.
To Run an operator, all input has to be instantiated. Once this is done, click on the Execute button for the operator. If the operator runs successfully, it is shaded.
Values in the process can be visualized by clicking on the attribute or operator's name. In our example, if you click on the first data node, an image will be presented.
Click on the = button of an ADT to create a constant of that ADT.
In this same manner we specify all operators and links.
Enter more operators until the whole process is specified.

Matthew O. Ward (matt@cs.wpi.edu)