Galaxy ProTo 2.0 Redux: Dynamic tool prototyping using interactive tools

In GCC2015 and GCC2016 we presented Galaxy ProTo v1 which demonstrated a novel approach to tool development for Galaxy. By replacing the XML middle layer with a template-based API in Python, we provided researchers, master students and other tool developers with a platform for on-the-fly development of dynamic web tools using pure Python. ProTo tools were ideal for prototyping novel functionality for demonstration to supervisors or testing of "avant garde" functionality by research collaborators and allowed the use of the powerful reproducibility and sharing features inherent in Galaxy without the overhead of learning to master the Galaxy tool development back end. By defining Python functions that returned simple Python objects, e.g. strings, lists, dicts, and lists of lists, the web tool interface would automatically and immediately generate corresponding user interface elements: text boxes, drop-down lists, multiple selection list boxes and tables, respectively. Contrary to the standard Galaxy XML interface, Galaxy ProTo v1 did not limit how the contents of the user interface would be populated and allowed highly dynamic interfaces that could depend on e.g. input file contents, earlier user selections, and/or external databases. Unfortunately, Galaxy ProTo v1 was only available as an unofficial fork of the Galaxy code base and the functionality was never offered as part of a vanilla Galaxy installation. After lying dormant for a few years, we have now resurrected the idea and code base but replaced the technological underpinnings to allow for distribution and use with vanilla Galaxy installations. Galaxy ProTo v2 runs as a web server in a Docker (or Podman) container which connects to the Galaxy API through the Interactive Tools functionality of Galaxy. Using a variant of the Data Source tool type, we can connect to the web server from other Galaxy tools and display the interactive user interface as if it was provided by the Galaxy server. Jobs can then be executed by Galaxy through a standard backend which runs jobs securely in containers. This will be extended with a continuous deployment solution to once again allow on-the-fly development of fully dynamic prototyping tools in Galaxy. We will present an early technological demo of Galaxy ProTo v2 in order to receive community feedback on the functionality and raise interest from core developers in the Galaxy Projects to help integrate a few generally useful additions to the Galaxy code base that is needed to make Galaxy ProTo v2 work on a vanilla Galaxy installation.