Building blocks using data

I'm trying to make code to make blockly-type blocks for html. This is blockly --> https://developers.google.com/blockly. This needs to be predictive not a check after code has already been written. I know html5 isn't completely serializable but some of it is. For example input elements have a type attribute. If I had a good source for scraping those very basic types of relationships between some of the elements and some other elements and attributes then it's possible I could parse/use that data to build my blocks.

Does anyone have advice about where I can find an up-to-date source of data? If possible I'd like data that works for Chromium but I'll take what I can get. Does any source exist in a way that could be useful to me or is all this validation done purely with logic now? One idea is to scrape the MDN site. I could scrape Chromium code possibly.

Does anyone have any other advice about how I could go about this other than manually writing out the data and then manually updating whenever anything changes?

p.s. the freenode channel is supposed to be #validator but there was nobody there when I went on. I saw it listed at https://validator.w3.org/feedback.html#mailinglist. Is it somewhere new now?