Block Shelves for Visual Programming Languages

TL;DR

This paper introduces block shelves, a new formatting tool for visual programming languages like Scratch, which improves readability, structure, and re-use of block code, demonstrated through enhancements in MIT App Inventor 2.

Contribution

The paper presents a novel block shelves tool that organizes blocks in VPLs, enhancing readability, structure, and re-use capabilities, with implementation in Google Blockly.

Findings

Improved block code navigation and searching.

Enhanced code re-use via shelf export/import.

Demonstrated effectiveness on MIT App Inventor 2.

Abstract

The blocks editor, such as the editor in Scratch, 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, while all modifications were made in Google Blockly.