Allow for no word separator in names of generated files

- Allow the use of an empty string to separate words in generated file names
- Add EmptyStringTransformer value transformer to convert nil to empty string
- Initialize new transformer in AppDelegate +initialize
- In Preferences storyboary set separator text field to use value transformer
- Resolves #63

Author: dempseyatgithub

BuildSettingExtractor/AppDelegate.m

@@ -26,6 +26,11 @@ @interface AppDelegate () <NSOpenSavePanelDelegate>
 
 @implementation AppDelegate
 
++ (void)initialize {
+    EmptyStringTransformer *transformer = [[EmptyStringTransformer alloc] init];
+    [NSValueTransformer setValueTransformer:transformer forName:@"EmptyStringTransformer"];
+}
+
 - (void)awakeFromNib {
     self.dragFileView.target = self;
     self.dragFileView.action = @selector(handleDroppedFile:);

BuildSettingExtractor/Constants+Categories.h

@@ -59,3 +59,8 @@ extern NSErrorDomain const TPSBuildSettingExtractorErrorDomain;
 + (NSError *)errorForDestinationContainsBuildConfigFiles;
 
 @end
+
+#pragma mark -
+
+@interface EmptyStringTransformer: NSValueTransformer {}
+@end

BuildSettingExtractor/Constants+Categories.m

@@ -125,3 +125,26 @@ + (NSError *)errorForDestinationContainsBuildConfigFiles {
 }
 
 @end
+
+#pragma mark -
+
+@implementation EmptyStringTransformer
++ (Class)transformedValueClass { return [NSString class]; }
++ (BOOL)allowsReverseTransformation { return YES; }
+
+- (id)transformedValue:(id)value {
+    if ([value isKindOfClass:[NSString class]] && [value isEqualToString:@""]) {
+        return nil;
+    } else if (value == nil) {
+        return @"";
+    } else {
+        return value;
+    }
+}
+
+- (id)reversedTransformedValue:(id)value {
+    if (value == nil) { return @""; }
+    else { return value; }
+}
+@end
+

BuildSettingExtractor/Preferences/Base.lproj/Preferences.storyboard

@@ -273,10 +273,11 @@
                                             </textFieldCell>
                                             <connections>
                                                 <accessibilityConnection property="title" destination="ApD-gw-uD5" id="YUV-Fq-B5t"/>
-                                                <binding destination="FdP-VK-zkk" name="value" keyPath="values.TPSOutputFileNameSeparator" id="fuY-Ge-NPr">
+                                                <binding destination="FdP-VK-zkk" name="value" keyPath="values.TPSOutputFileNameSeparator" id="aYI-51-xnh">
                                                     <dictionary key="options">
                                                         <bool key="NSContinuouslyUpdatesValue" value="YES"/>
                                                         <string key="NSNullPlaceholder">None</string>
+                                                        <string key="NSValueTransformerName">EmptyStringTransformer</string>
                                                     </dictionary>
                                                 </binding>
                                             </connections>