Copy Autolayout Constraints

gistfile1.m

+ (void)copyConstraintsFromView:(UIView *)sourceView toView:(UIView *)destinationView
{
    NSPredicate *firstPredicate = [NSPredicate predicateWithFormat:@"firstItem = %@", sourceView];
    NSPredicate *secondPredicate = [NSPredicate predicateWithFormat:@"secondItem = %@", sourceView];
    
    NSArray *viewConstraints = sourceView.constraints;
    
    for (NSLayoutConstraint *constraint in [viewConstraints filteredArrayUsingPredicate:firstPredicate]) {
        NSLayoutConstraint *replacementConstraint = [self duplicateForConstraint:constraint
                                                                   withFirstItem:destinationView
                                                                      secondItem:constraint.secondItem];
        [destinationView addConstraint:replacementConstraint];
    }
    
    for (NSLayoutConstraint *constraint in [viewConstraints filteredArrayUsingPredicate:secondPredicate]) {
        NSLayoutConstraint *replacementConstraint = [self duplicateForConstraint:constraint
                                                                   withFirstItem:constraint.firstItem
                                                                      secondItem:destinationView];
        [destinationView addConstraint:replacementConstraint];
    }
    
    NSArray *superviewConstraints = sourceView.superview.constraints;
    
    for (NSLayoutConstraint *constraint in [superviewConstraints filteredArrayUsingPredicate:firstPredicate]) {
        NSLayoutConstraint *replacementConstraint = [self duplicateForConstraint:constraint
                                                                   withFirstItem:destinationView
                                                                      secondItem:constraint.secondItem];
        [destinationView.superview addConstraint:replacementConstraint];
    }
    
    for (NSLayoutConstraint *constraint in [superviewConstraints filteredArrayUsingPredicate:secondPredicate]) {
        NSLayoutConstraint *replacementConstraint = [self duplicateForConstraint:constraint
                                                                   withFirstItem:constraint.firstItem
                                                                      secondItem:destinationView];
        [destinationView.superview addConstraint:replacementConstraint];
    }
}