--- a/TypeConverter.st	Mon Feb 24 12:12:59 1997 +0100
+++ b/TypeConverter.st	Mon Feb 24 19:05:08 1997 +0100
@@ -64,6 +64,18 @@
     ^ (self on:aValueHolder) numberToText
 
     "Modified: 21.2.1997 / 18:46:11 / cg"
+!
+
+onSymbolValue:aValueHolder
+    "create and return a typeConverter, which retrieves
+     a symbol-values string representation via #value, and converts
+     a string to a symbol via #value:.
+     Useful as an editFields model, which operates on some
+     numeric value (or aspectAdaptor, which adapts to a numeric slot)"
+
+    ^ (self on:aValueHolder) symbolOrNil
+
+    "Modified: 21.2.1997 / 18:46:11 / cg"
 ! !
 
 !TypeConverter methodsFor:'accessing'!
@@ -180,10 +192,45 @@
         updateBlock: [:m :a :p | true]
 
     "Modified: 21.2.1997 / 18:59:44 / cg"
+!
+
+symbolOrNil
+    "setup the converter to convert from a string to a symbol
+     and vice versa. Invalid symbols (i.e. empty) are converted to nil."
+
+    self
+        getBlock:[:model |
+                |symbolValue|
+
+                (symbolValue := model value) isNil ifTrue:[
+                    String new
+                ] ifFalse:[
+                    '#' , symbolValue asString
+                ]]
+
+        putBlock:
+                [:model :string |
+
+                |value s|
+
+                string isEmpty ifTrue:[
+                    value := nil
+                ] ifFalse:[
+                    s := string withoutSeparators.
+                    (s startsWith:'#') ifTrue:[
+                        s := s copyFrom:2
+                    ].
+                    value := s asSymbol
+                ].
+                model value:value]
+
+        updateBlock: [:m :a :p | true]
+
+    "Created: 21.2.1997 / 18:58:38 / cg"
 ! !
 
 !TypeConverter class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libview2/TypeConverter.st,v 1.1 1997-02-21 18:09:11 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libview2/TypeConverter.st,v 1.2 1997-02-24 18:05:08 ca Exp $'
 ! !