Block Shelves for Visual Programming Languages

The blocks editor, such as the editor in Scratch [13], is widely applied for visual programming languages (VPL) nowadays. Despite it’s friendly for non-programmers, it exists three main limitations while displaying block codes: (1) the readability, (2) the program structure, and (3) the re-use. To cope with these issues, we introduce a novel formatting tool, block shelves, into the editor for organizing blocks. A user could utilize shelves to constitute a user-defined structure for the VPL projects. Based on the experiment results, block shelves improves the block code navigating and searching significantly. Besides, for achieving code re-use, users could use shelf export/import to share/re-use their block codes between projects in the file format of eXtensible Markup Language (xml.) All functions were demonstrated on MIT App inventor 2 [12], while all modifications were made in Google Blockly. Author