Hierarchical Graph Model Of Visual Programming Components And Its Application

Unlike the text-based programming language,visual programming language enables the underlying function to be encapsulated,requiring only the users simply drag and drop the programming components to complete the programming tasks with complex logic.For majority people of non-computer professionals,simple and intuitive visual programming language is their gospel.But the existing softwares,whose system coupling is high,do not support the programming component expansion and multi-thread synchronization,and the running speed is slow.These disadvantages bring users inconvenience.This paper proposes a Visual-programming Directed Acyclic Graph model – VDAG to solve these problems and implemented it.The model is based on directed acyclic graphs,with low coupling,low space-time complexity,and supports component expansion and multi-thread synchronization.This paper analyzes the features of meta visual programming components through modeling requirements,defines a hierarchical model that can describe visual programming efficiently,illustrates the characteristics of the model,and designs its data structure.By analyzing and describing the characteristics of the three-layer model and the sufficient experimental comparison,it is shown that this special hierarchical directed acyclic graph model-VDAG can describe the flow of logic and data between the visual programming components very well.Finally,this paper presents implementation based on hierarchical graph model and introduces the application of the system.The implementation of the system uses the message-driven mechanism to ensure that the back-end compile part and the front-end display part are in loose coupling.And finally,the final codes or executable programs can be generated through the implementation of visual programming compilation.