Swift: Can I get information for an application which is not running?

I am writing an application which stores data about other applications. I can find the current front most application and its information easily enough:

let frontApp = NSWorkspace.shared.frontmostApplication!

and from there I can get:

let currentAppName = currentApp.localizedName ?? "Dunno"
let currentAppIcon = currentApp.icon

If the application is not in the foreground, I know I can iterate through other running applications:

let apps = NSWorkspace.shared.runningApplications
for app in apps as [NSRunningApplication] {
    print(app.localizedName ?? "whatever")
    print(app.bundleIdentifier ?? "bundle")
}

I would like to get the same information about a application which is not currently running, but for which I do have the bundle identifier. How can I get this?

Solution

First, get the application's bundle using

let bundleURL = NSWorkspace.shared.urlForApplication(withBundleIdentifier: someBundleID)!
let bundle = Bundle(url: bundleURL)!

Once you have the bundle, you can get most of the things that you can get from a NSRunningApplication:

bundleIdentifier you already know.
bundleURL you just got with the code above.
executableArchitecture is now bundle.executableArchitectures, with a plural. Because it's not running, you get all the architectures that it can be run on, rather than the specific architecture that it is running on.
executableURL you can get with bundle.executableURL, no problems there.
launchDate, isFinishedLaunching, processIdentifier, ownsMenuBar are nonsensical to get, since the application is not running.

Now we are left with icon and localizedName. The methods I propose for getting these are less reliable. To get icon, do

NSWorkspace.shared.icon(forFile: bundleURL.path)

I'm sure this produces the same result as NSRunningApplication.icon at least 99% of the time, but I'm not sure if there are edge cases...

To get localizedName is more unreliable. There are 2 ways, neither of which are good. Choose the one that fits your purpose the best

FileManager.default.displayName(atPath: bundleURL.path) This gives you the localised name, but if the user renames the application, it will return the new name, rather than the bundle name
Getting CFBundleDisplayName from the bundle's localizedInfoDictionary, falling back on CFBundleName and infoDictionary. This for some reason doesn't give the localised name, even though I said localizedInfoDictionary.
```
let infoDict = (bundle.localizedInfoDictionary ?? bundle.infoDictionary)
let localizedName = infoDict?["CFBundleDisplayName"] ?? infoDict?["CFBundleName"]
```