ENVIWorkflow::Connect

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

ENVI 5.6

Introduced

API Version

4.2

See Also

ENVIWorkflow