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Apps Manager

import { appsManager } from "/42/api/os/managers/appsManager.js"
// Or
const appsManager = sys42.apps

The apps manager keeps the list of installed apps and launches them.

tip

Understanding the apps manager is fundamental to building a process manager, or any app that interacts with other apps.
If you're trying to make your app single-instance, just add solo: true to the manifest.

Its config file is the user's config/apps.json5. It is a map of command → app manifest. It's also available globally, at sys42.apps.

Manifests​

The manifests stored in the apps manager is different from the one in app.manifest.json5.
The program directory is determined by the directory app.manifest.json5 is in.

Manifest normalization logic

The manifest normalizer is in charge of more than just normalization.

Icons​

  • It looks for icons in the program's directory and adds them to the manifest's icons property.
    • It recursively looks in the icons/ directory, as well as any files that start with icon in the program directory (not recursive)
  • It registers 16x16, 32x32, and 160x160 icons.
    • 160x160 is an unused size that was present in the v3 beta.
  • jpg, gif, svg, and png are the only file extensions supported. Note that jpeg is not included.
  • If an icon's name (not incl. file extension) is simply icon, it is registered as a 32x32 icon.
  • It expands the icon property into icons, and registers it as the 32x32 size.

Encode/Decode​

Command​

The command is made lowercase, truncated at the first period (if any), and stripped of any non-alphabetical characters.
If there is no command it takes the name of the program and does the process above.

When the manifest normalizer runs, it adds an property, updated, to the manifest with Date.now().

setup() watches the file index for new or deleted manifests and installs or removes them accordingly. It also compares the remote /apps.cbor Last-Modified header to the local version and updates when the remote is newer.

Installing​

Installing an app (add() / updateAll()):

  • normalizes the manifest and stores it under value[command].
  • registers decode types with the mimetypes and icons managers.
  • writes a .desktop shortcut next to the manifest.
  • creates a tray icon when the manifest has a tray entry.
  • emits an "add" event.

A manifest whose command is already taken is rejected with an error toast, unless update: true.

Launching​

  • launch(appName, options) - launches an app by command or name. Apps with audio input are routed to AudioApp.
  • open(paths, options) - opens files. Directories open in the explorer, other paths are grouped by default app and launched.
  • lookup(path) - returns the manifests that can open a path.

launched is a WatchMap of instance id → running App. It emits add and delete events.

This means you can easily get the App instance of an app by running appsManager.launched.get(id)

Helpers​

  • getManifest(appName) - resolves a manifest by command or name.
  • getAppIcon(appName, size) - icon for an app, falling back to the generic app icon.
  • createDesktopIcon() / writeDesktopIcon() - build and write .desktop shortcuts.
  • initTrays() - recreates tray icons for all apps with a tray entry.
  • listenIframeActions() / addIframeLiveReload() - wire running iframe apps to actions and live reload.