1 files changed, 53 insertions, 0 deletions
diff --git a/src/osx/NilToEmptyStringTransformer.m b/src/osx/NilToEmptyStringTransformer.m
new file mode 100644
index 0000000..97267e3
--- /dev/null
+++ b/src/osx/NilToEmptyStringTransformer.m
@@ -0,0 +1,53 @@
+//
+//  NilToEmptyStringTransformer.m
+//  TikZiT
+//  
+//  Copyright 2011 Aleks Kissinger. All rights reserved.
+//  
+//  
+//  This file is part of TikZiT.
+//  
+//  TikZiT is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//  
+//  TikZiT is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//  
+//  You should have received a copy of the GNU General Public License
+//  along with TikZiT.  If not, see <http://www.gnu.org/licenses/>.
+//  
+
+#import "NilToEmptyStringTransformer.h"
+
+@implementation NilToEmptyStringTransformer
+
+- (id)init {
+    [super init];
+    return self;
+}
+
++ (Class)transformedValueClass {
+    return [NSString class];
+}
+
++ (BOOL)allowsReverseTransformation {
+    return YES;
+}
+
+- (id)transformedValue:(id)value {
+    if (value == nil) {
+        return @"";
+    } else {
+        return value;
+    }
+}
+
+- (id)reverseTransformedValue:(id)value {
+    return [self transformedValue:value];
+}
+
+@end