Using Meta Nodes

Meta nodes are nodes that contain subworkflows, i.e. in the workflow they look like a single node, although they can contain many nodes and even more meta nodes. They are created with the help of the meta node wizard. You can open the meta node wizard by either selecting "Node/Add Meta Node" from the menu or by clicking the button with the meta node icon in the toolbar (workflow editor must be active).

Create Pre-defined Meta Node

To create a pre-defined meta node, select one and click "Finish". The one you have selected is added to the workflow.

screenshot of meta node wizard first page

Create Customized Meta Node

If you need either a different number of in- or out-ports or want to have different port types you can select one of the pre-defined meta nodes as a template and then click "Customize" to access the next page of the wizard.

screenshot of meta node wizard second page

On this page you can add or remove in- and out-ports of the template. An icon at the bottom immediately gives you a preview of the node. When you add a port to the template you can choose the type for the port:

data,
data base or
data mining port (PMML).

Once the node fits your needs, click "Finish" in order to add it to the workflow.

Inside a Meta Node

In order to open a meta node you can either double-click it or choose "Open Subworkflow editor" from its context menu. Depending on the amount of in- and out-ports the inside of a meta node looks similar to the picture below:

The in- or out-ports are fixed to the so-called workflow port bars, which can be moved and resized. The data connected to the in-port from outside appears inside the meta node editor in the in-port. And vice versa: the data connected to the inner out-port appears in the outer out-port.

Meta Nodes From Outside

Meta nodes look different to normal nodes. The background icon is not rounded and has a dark gray background. There is no status light and no progress.

States of Meta Nodes

A meta node does not have as many states as a node. The states of a meta node are the same as the states of a workflow. A meta node can be

idle/configured: If there is at least one node inside the meta node that is neither executed nor executing.
executing: If at least one node is executing
executed: If all contained nodes are executed

The state of a meta node is displayed by an icon in the meta node (seen from outside).

Out-Ports of Meta Nodes

In addition to the state of the meta node the out-ports of a meta node also have states. A small decorator icon displays the state of the out-port.

If a port is not connected or connected to an idle node neither specs nor data are available. This is indicated by a red icon.

If a port is connected to a configured node, some specs are available. This is indicated by a yellow icon.

If a port is connected to an executed node, specs and data are available. This is indicated by a green icon.