No No No!
Don't use a category like that, it has unexpected behaviour, you should always namespace your category methods.
e.g.
@implementation UIFont (OKASystemFontOverride)
+ (UIFont *)oka_boldSystemFontOfSize:(CGFloat)fontSize;
{
return [UIFont fontWithName:@"ArialHebrew-Bold" size:fontSize];
}
+ (UIFont *)oka_systemFontOfSize:(CGFloat)fontSize;
{
return [UIFont fontWithName:@"Arial" size:fontSize];
}
@end
You must then explicitly set the font on any labels you have.
myLabel.font = [UIFont oka_systemFontOfSize:17.f];