Opens the standard C4D COFFEE Expression Editor.

Compiles (parses the code and checks for its validity) the script code.

Here you can write the COFFEE script that is evaluated by the caller node.

There are predefined Effex variables that you can access beside the usual COFFEE functionality or that offer you information about the data the caller node processes.

main(op) - op is the COFFEE constraint itself (the correct object pointer is passed here during rendering...so you can extract the render basedocument from it)
intensity - the node's "Intensity" slider value
physical_pos - the physical position of the sample currently processed
source_value - the current constraint value. Imagine other constraints have been evaluated before this constraint is. Then the original source value has been altered and this variable holds the current, modified value.

This list takes nodes of type "Value".
Once you assigned a Value node, the script code automatically creates a new variable which is named equal to the Value node's name.

Example:
The Value node's name is "brains", then you can automatically access the variable "brains" in the script which allows to access the Value node value.

Therefore you can create an arbitrary amount of new float, integer or vector variables and control them from within the Value node's settings.