I'm trying to use a groovy expression to populate the summary field from a postfunction.
I want to string together the values of three custom fields and have that be the issue's summary.
Starting with baby steps, I'm trying to set the summary field to just one of the custom field values. No success.
I am NOT a groovy developer or any other kind of developer. Which is defintely a problem since I'm not sure what a groovy expression is.
When I put for following in for a groovy expression I get the error shown below.
string issue.get("customfield_12230") /secure/QuickCreateIssue.jspa [jmwe.plugins.functions.SetFieldValueFunction] Error while executing SetFieldValueFunction: groovy.lang.MissingMethodException: No signature of method: Script1.string() is applicable for argument types: (java.lang.String) values: [Add] Possible solutions: toString(), toString(), print(java.lang.Object), sprintf(java.lang.String, [Ljava.lang.Object
, print(java.io.PrintWriter), sprintf(java.lang.String, java.lang.Object) groovy.lang.MissingMethodException: No signature of method: Script1.string() is applicable for argument types: (java.lang.String) values: [Add]
That's not bad considering that the value in the custom field is in fact "Add". But obviously it didn't work.
When I drop "string" I get no errors in the logs, but neither does it populate the Summary field.
All help appreciated. And if the answer can be in non-developer speak, even better! 
Thanks.