The book is NOT even close to being a good book. Put simply, it's full of errors that will leave you scratching your head, not knowing what to
do and more importantly how to do it. It's just a huge, total waste of your time, period.
What's more, the three of them just get lost in what's their wish to sound professional and skilled but that unfortunately brings them to
feed you usless code containing as I said a host of stupid mistakes.
How would you regard a programmer using such variable names ? :
$objThisFailingConstraintObject = $objThisConstraintFailure->GetFailedConstraintObject();
...names that he can't recall himself a few lines after ( $_blIsRedirectFollowingConstraintFailure becomes $_blIsRedirectOnConstraintFailure ).
It would take ages to explain the whys of the uslesness of this book and to list all the errors contained in it.