Added respondToSelector check in didDeselectCellAtRow and shouldSelectItemAtIndexPath since both are optionals methods

Author: Joaquin Perez Lopez

DRCollectionViewTableLayout/DRCollectionViewTableLayoutManager.m

@@ -194,18 +194,34 @@ - (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndex
     NSUInteger row = [(DRCollectionViewTableLayout *)collectionView.collectionViewLayout rowNumberForIndexPath:indexPath];
     NSUInteger column = [(DRCollectionViewTableLayout *)collectionView.collectionViewLayout columnNumberForIndexPath:indexPath];
 
-    [self.delegate collectionViewTableLayoutManager:self
+    SEL selector = @selector(collectionViewTableLayoutManager:collectionView:didDeselectCellAtRow:column:indexPath:);
+    
+    if ([self.delegate respondsToSelector:selector]) {
+    
+        [self.delegate collectionViewTableLayoutManager:self
                                      collectionView:collectionView
                                didDeselectCellAtRow:row
                                              column:column
                                           indexPath:indexPath];
+    }
 }
 
 - (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath {
     NSUInteger row = [(DRCollectionViewTableLayout *)collectionView.collectionViewLayout rowNumberForIndexPath:indexPath];
     NSUInteger column = [(DRCollectionViewTableLayout *)collectionView.collectionViewLayout columnNumberForIndexPath:indexPath];
 
-    return [self.delegate collectionViewTableLayoutManager:self collectionView:collectionView shouldSelectItemAtRow:row column:column indexPath:indexPath];
+    SEL selector = @selector(collectionViewTableLayoutManager:collectionView:shouldSelectItemAtIndexPath:column:indexPath:);
+    
+    if ([self.delegate respondsToSelector:selector]) {
+        
+        return [self.delegate collectionViewTableLayoutManager:self
+                                                collectionView:collectionView
+                                         shouldSelectItemAtRow:row
+                                                        column:column
+                                                     indexPath:indexPath];
+    }
+    
+    return YES;
 }
 
 @end