Connecting workflow elements

Connections between workflow element output channels and input channels define where data flows from and to.

The names of output channels usually indicate the type of data generated and the names of input channels usually indicate the type of data expected. Connections can only be made between compatible output and input channels.

An output channel can be connected to more than one input channel and an input channel can accept data from more than one output channel (figure 14.7).

Image workflow_multiple_connections
Figure 14.7: In this workflow, two elements are supplying data to the Reads input channel of the Map Reads to Reference element, while data from the Reads Track output channel of Map Reads to Reference is being used as input to two elements.

Connecting output and input channels

Two ways that compatible input and output channels can be connected are:

Information about what elements and channels are connected

In a small workflow, it is easy to see which elements are connected and how they are connected. In large workflows, the following methods can be helpful:

Image workflow_mouse_over_connection
Figure 14.10: Hover the mouse cursor over a connection to reveal a tooltip containing the names of the elements and channels connected.

Image workflow_connection_right_click
Figure 14.11: Right-click on a connection to reveal options to jump to the source element or the destination element of that connection.

Removing connections

To remove a connection, right-click on the connection and select the Remove option (figure 14.11).