Use the Connect method to connect two steps in a workflow. This method internally uses the Add method to add steps to a workflow. Connecting steps serves two purposes in a workflow: it determines what internal variables need to be passed around, and it establishes the execution order of steps.
Example
See the example for ENVIWorkflow. This example connects the output raster in Step 1 to the input raster in Step 2.
Syntax
To pass data from one step to another:
ENVIWorkflow.Connect, FromStep, FromParameters, ToStep, ToParameters [, ERROR=value]
To connect two steps without passing data between them:
ENVIWorkflow.Connect, FromStep, ToStep [, ERROR=value]
Arguments
FromStep
Specify the source step for the connection.
FromParameters
Specify a string or array of strings with a valid task parameter name (for example, OUTPUT_RASTER) in FromStep.
ToStep
Specify the target step for the connection.
ToParameters
Specify a string or array of strings with a valid task parameter name (for example, INPUT_RASTER) in ToStep.
Keywords
ERROR
Set this keyword to a named variable that will contain any error message issued during execution of this routine. If no error occurs, the ERROR variable will be set to a null string (''). If an error occurs and the routine is a function, then the function result will be undefined.
When this keyword is not set and an error occurs, ENVI returns to the caller and execution halts. In this case, the error message is contained within !ERROR_STATE and can be caught using IDL's CATCH routine. See IDL Help for more information on !ERROR_STATE and CATCH.
See Manage Errors for more information on error handling in ENVI programming.
Version History
API Version
4.2
See Also
ENVIWorkflow