Simon Willison’s Weblog


Monday, 22nd July 2019

When a rewrite isn’t: rebuilding Slack on the desktop. Slack appear to have pulled off the almost impossible: finishing a complete, incremental rewrite of their core product. They moved from jQuery to React over the course of two years, constantly shipping new features as they went along. The biggest gain was in rewriting their code to support multiple workspaces, which means desktop client users no longer have to run a separate copy of Electron for every workspace they are signed into. # 6:30 pm

healthkit-to-sqlite. Ever since I got an Apple Watch I’ve been itching to get my hands on the step tracking and health data that it’s been collecting for me. I know it’s there in a SQLite database on my wrist, but I couldn’t figure out how to get it! A few days ago I stumbled across the “Export Health Data” button in the iOS Health app, and it turns out it creates a zip file containing XML with a full dump of the data collected by Apple Health. healthkit-to-sqlite is the tool I’ve built that can read that export and use it to create a SQLite database ready to be queried and explored with Datasette. It’s a pretty basic implementation but it’s already giving me access to over 3 million rows of data. Lots of potential here for interesting work with personal analytics. # 3:34 am

2019 » July