In this blog post we will demonstrate how you can implement methods that save and load part of the information that a diagram renders into JSON format. The Diagram class has built-in toJson and fromJson methods. They serialize completely the diagram with every detail so you can restore it completely, exactly the way you see it. What we are going to do is write custom save and load methods that use only part of the information – namely the size and location of nodes and links as well as their text.