I’m pleased to announce the latest in my PreviewApps series: PreviewJson. It taps into macOS’ QuickLook feature to provide at-a-tap previews of JSON files and generates Finder icon thumbnails for them too. There are some updates out too.

I’m pleased to announce the latest in my PreviewApps series: PreviewJson. It taps into macOS’ QuickLook feature to provide at-a-tap previews of JSON files and generates Finder icon thumbnails for them too. There are some updates out too.
Last week I announced the release of a new version of PreviewMarkdown that will preview YAML front matter in Markdown files. Work on that release prompted me to code a new app that enables QuickLook previews and Finder icon thumbnails of YAML files.
Continue readingA couple of macOS releases or so ago, Apple introduced app extensions: self-contained modules that are bundled within apps to deliver functionality to the wider operating system. But how do apps and their extensions share information between themselves, in particular users’ preferences?
Continue readingAnother day, another update. This time it’s PreviewMarkdown, my macOS utility for providing QuickLook file previews and icon thumbnails in Finder. It runs under Catalina and above, and this version makes some adjustments to support Big Sur.
You can read more about using PreviewMarkdown — just run it once to register its app extensions, and that’s it — it the product page here. You can download PreviewMarkdown from the Mac App Store.
Update My PreviewMarkdown app, which provides Markdown file previews and icon thumbnails in Catalins, is now available from the Mac App Store.
Providing content-based icon thumbnails in macOS Catalina follows the same pattern as generating file previews: QuickLook runs code from an app extension and calls a function within that code to draw the image that will be placed on the icon.