Truth be known, I would predict that most people would not associate "joyful" and "apocalypse" in the same context as suggested in the title of this book. However, the truth of the Book of Revelation is that it is a message of joy, hope, healing, and peace.
Generally we associate Apocalypse with war, famine, pestilence, doom, gloom, and every other scary thing we can imagine. John's purpose was not to scare us-rather, he wrote to inspire and motivate us to goodness. He was privileged to receive a true revelation from God and to write it for our spiritual growth.
Interestingly, the word apocalypse means to unveil, to reveal, and to uncover. We find that the themes of joy and hope are revealed and are woven throughout the Revelation and that God has unveiled His message and truly desires to reveal to us the path He would have us walk to return to live with Him someday. The true message of John's vision is that God lives and that He loves us and that good will triumph over evil in this world.