IDL Reference Guide: Miscellaneous Object Classes

IDL_IDLBridge::GetVar

The IDL_IDLBridge::GetVar function copies the value of a variable from the child process to the parent process. The variable must exist in the child process at the $MAIN$ level. See Examples for more information.

IDL_IDLBridge::GetVar is subject to the following limitations:

Syntax

Result = Obj->[IDL_IDLBridge::]GetVar(VarName)

Return Value

Returns the value of the variable transferred from the child process.

Arguments

VarName

A string containing the name of the variable to be transferred from the child process.

Keywords

None

Examples

The GetVar method can return the value of a variable that exists at the $MAIN$ level of the child process. In the following example, GetVar returns image data. Note that the mrifile variable and data variable are created in the child process as a result of executing the Execute statement.

; Create a child process.   
oBridge=OBJ_NEW('IDL_IDLBridge')  
  
; Access a file and pass it to the child process in a variable  
; called file.  
mriFile= FILEPATH('pdthorax124.jpg', $  
   SUBDIRECTORY = ['examples', 'data'])  
  
; Extract the image data in the child process into a   
; variable named data.  
oBridge->Execute, "READ_JPEG,'" + mrifile + "', data"  
  
; Access the image data using GetVar and display it.  
imgData = oBridge->GetVar('data')  
IIMAGE, imgData  

You can also access information about a child process using the HELP procedure. For example, if you set a breakpoint in a parent IDL process at a point where IDL_IDLBridge object status can be obtained (such as during an Abort, where you can access an IDL_IDLBridge object that is not actively executing a command), you can use GetVar to return HELP information as follows:

oBridge->Execute, 'HELP, /FULL, OUTPUT=x'  
PRINT, oBridge->GetVar('x')