Add convenience initialiser to Field class for invisible fields

Author: Eitot

Vienna/Sources/Database/Database.m

@@ -452,11 +452,7 @@ -(NSInteger)countOfUnread
                customizationOptions:VNAFieldCustomizationResizing],
         [[Field alloc] initWithName:MA_Field_GUID
                                type:VNAFieldTypeInteger
-                           sqlField:@"message_id"
-                        displayName:nil
-                            visible:NO
-                              width:72
-               customizationOptions:VNAFieldCustomizationResizing],
+                           sqlField:@"message_id"],
         [[Field alloc] initWithName:MA_Field_Subject
                                type:VNAFieldTypeString
                            sqlField:@"title"
@@ -491,11 +487,7 @@ -(NSInteger)countOfUnread
                customizationOptions:VNAFieldCustomizationAll],
         [[Field alloc] initWithName:MA_Field_Parent
                                type:VNAFieldTypeInteger
-                           sqlField:@"parent_id"
-                        displayName:nil
-                            visible:NO
-                              width:72
-               customizationOptions:VNAFieldCustomizationResizing],
+                           sqlField:@"parent_id"],
         [[Field alloc] initWithName:MA_Field_Author
                                type:VNAFieldTypeString
                            sqlField:@"sender"
@@ -546,11 +538,7 @@ -(NSInteger)countOfUnread
                customizationOptions:(VNAFieldCustomizationVisibility | VNAFieldCustomizationResizing)],
         [[Field alloc] initWithName:MA_Field_EnclosureDownloaded
                                type:VNAFieldTypeFlag
-                           sqlField:@"enclosuredownloaded_flag"
-                        displayName:nil
-                            visible:NO
-                              width:100
-               customizationOptions:VNAFieldCustomizationResizing],
+                           sqlField:@"enclosuredownloaded_flag"],
     ];
     return _fields;
 }

Vienna/Sources/Database/Field.h

@@ -48,6 +48,10 @@ typedef NS_OPTIONS(NSUInteger, VNAFieldCustomizationOptions) {
                        width:(NSInteger)width
         customizationOptions:(VNAFieldCustomizationOptions)customizationOptions;
 
+- (instancetype)initWithName:(NSString *)name
+                        type:(VNAFieldType)type
+                    sqlField:(NSString *)sqlField;
+
 /// The field name is the unlocalised display name; useful for writing to data
 /// files where sysName isn't appropriate.
 @property (copy, nonatomic) NSString *name;

Vienna/Sources/Database/Field.m

@@ -54,6 +54,19 @@ - (instancetype)initWithName:(NSString *)name
     return self;
 }
 
+- (instancetype)initWithName:(NSString *)name
+                        type:(VNAFieldType)type
+                    sqlField:(NSString *)sqlField
+{
+    self = [super init];
+    if (self) {
+        _name = [name copy];
+        _type = type;
+        _sqlField = [sqlField copy];
+    }
+    return self;
+}
+
 // MARK: Overrides
 
 - (NSString *)description