In Taverna 2.4 and later, String Constant has been replaced by Text Constant.

A String constant service allows you to set a fixed-value input for a service or the whole workflow. This is useful for inputs that are fixed across multiple runs of the same workflow, and also for publishing your workflows since the string constant provides an example input for people wanting to try out the workflow.

Adding a String Constant

  1. Expand Service templates under Available services in the Service Panel.
  2. Select String constant.
  3. Drag String constant and drop it into the Workflow Diagram.
  4. In a dialog that pops up, enter the String value you want to set the String constant to.

Note that you can add a String constant from the Insert menu as well.


 

Setting a Constant (Default) Value for a Service

  1. Right-click on the input port of a service in Workflow Diagram and select Constant value.


Alternatively, you can drag in a String Constant from the Service Templates section of the Service Panel, as explained in the previous section, and connect it to the appropriate input port of your service.