title: Building a NSPredicate for a filter
body: <p>Just wondering what the best way to build a NSPredicate is if some filters are optional?</p>
  
  <p>This is basically for a filter, so if some options aren't selected I don't to filter by them</p>
  
  <p>eg. If I have option1 and option2 set for the filter.</p>
  
  <p>NSPredicate* predicate = [NSPredicate predicateWithFormat:@"option1 = %@ AND option2 = %@] ....</p>
  
  <p>otherwise if just option1
  NSPredicate* predicate = [NSPredicate predicateWithFormat:@"option1 = %@] ....</p>
  
  <p>The key being there are 10 different options to filter, so I don't want to have to code for the 10x10 possible combinations.</p>
  
  <p>Thanks</p>