Patent US 6,990,652

A method for developing an automation client program in a graphical programming environment is disclosed. The graphical programming environment provides a set of automation nodes that may be wired together to create a graphical program, including nodes for referencing user-selected automation classes from automation type libraries exported by automation server applications; nodes for instantiating objects from the selected automation class; and nodes for invoking user-selected methods and/or properties of the automation class. A method for performing class and/or type propagation checking of automation objects in graphical programs is also disclosed. The automation class of a first automation node is propagated from the first node to a second automation node when the two nodes are wired together or when the automation class of the first node is changed to a second class. The automation nodes perform type checking to verify that the user-selected method or property is valid for the automation class of the node.