At the moment, the codemirror editor js variable created by DialogEditCode is local to the anonymous js function that instantiates it (the var keyword is used). We need to make its scope global so that other scripts can access it. In particular, I am thinking about the groovy module and this long-standing bug MGNLGROOVY-35.
This should be safe in case there are multiple instances of the DialogEditCode control, since each editor variable should be created with a unique name.