Command: Extract function

Function: The command opens the Extract Function Configuration dialog.

The command extracts selected code from the ST editor and creates a new method or function containing this code. The affected code in the ST editor is replaced by a correct call. When code is extracted from a function block or the child of a function block, a new method is created from the code. When code is extracted from a program or a function, a new function is created from the code.

Note also in this context: Detecting Code Clones

Call: Context menu: Refactoring

Requirements: When the selected code consists of one or more statements:

The selected code does not contain any compile errors.
The selected code is located in the implementation part of an ST POU.
The selected code does not contain any exiting jumps
Examples of exiting jumps include the following:
- Using RETURN to exit the enclosing function
- Using CONTINUE or EXIT to exit a loop enclosing the code

Tip

You can undo the changes that the Extract function command made in your project by positioning the cursor in the device tree and clicking Edit → Undo.

Table 1. Extract Function Configuration Dialog

Name	Name of the recently created function or method The default name can be changed.
Return value	Determines the return value of a function if there are multiple output and/or input/output parameters
Parameter	Display of the available POUs Configuration whether the parameters are used as input, output, or input/output variables : Input variables : Output variables : Input/Output variables
	The changes made for Name, Return value, or Parameter are undone.
Upper code window	Recently created code of the call location
Lower code window	Recently created code of the function or method
OK	The displayed code changes are accepted in the ST POUs and the dialog is closed.
Cancel	The displayed code changes are rejected and the dialog is closed.