Open External App on Mac

Photoshop UXP Plugin API
1

I have an issue on mac when trying to open an external app from an uxp plugin, where the call shell.openPath() fails w/: “Extension “” is not accepted for the path”. The manifest contains the “.app” entry in the extensions array. If I try to open an arbitrary file (e.g. rtf), w/out adding the extension to the manifest, I’ll get back the same error, but w/ extension listed in the message: “Extension “.rtf” is not accepted for the path”.
Opening an app (.exe) on windows, using the same call, succeeds.
The openExternal cannot be used because ‘file’ scheme is not supported.

2

please share the relevant parts of the manifest so we can help you better.

also sharing minimal code could help.

3

Manifest:
“manifestVersion”: 5,
“requiredPermissions”: {
“localFileSystem”: “request”,
“launchProcess”: {
“schemes”: [
“https”
],
“extensions”: [
“.png”,
“.exe”,
“.app”
]
}
}

Code:
try {
await shell.openPath(“/Users/…/external.app”)
}

4

I don’t have access to a mac machine, but I can assure you that the manifest is correct and your code does work on windows.

for the sake of testing, could you please try the following

    "launchProcess": {
      "schemes": [
        "https",
        "file",
        ""
      ],
      "extensions": [
        ".png",
        ".exe",
        ".app"
      ],
      "network": {
        "domains": "all"
      }
    }

if it still doesn’t work, please try with file:/:

await shell.openPath("file://Users/…/external.app")

please note that reloading the plugin is not enough when editing the manifest, you’ll need to unload and the load it so changes apply.

5

Thank you for looking into this.
We verified the code in windows, and it’s working.
Your suggestion to use ‘file://’ w/ the openPath call was a good one, because after I made the change, I got the prompt ‘Request for Permission’ (allow/block app). Unfortunately after clicking on Allow, I got an error message: “File not found”. The app can be launch w/out any problems from finder.
image

6
  1. does other extensions work?
  2. have you tried other locations?
  3. are you sure about the file path, maybe try it a browser? to narrow down the issue
7

If I try to open a jpg, using openPath("file://path), I’ll get the same behavior as before: permission prompt and then the error. If I don’t prepend the ‘file://’ to the path, then openPath(path) works for that jpg (or a txt file).
I double checked the path and it’s correct. Actually, all the test files are located on the plugin’s root.
To me it looks like a mac specific issue, when opening an external app. It would be great if another mac user could try it out.

8

could be a security issue. the call must be getting blocked somewhere.

how about running a script that starts the .app? does it work

other people confirmation would be great

9

I tried on a mac and .app did not work.

Perhaps it is because .app is actually a folder. What is executed is the executable file inside it.

So I added "" to the allowed extensions and it worked. A dialog box appears asking if I want to allow it or not.

"extensions": [
  "",
  ".png",
  ".exe",
  ".app"
],
2 Likes
10

That was a good suggestion. After adding an empty extension “” to the manifest, the call openPath(“/Users/…/external.app”) succeeds and the app is launched. Thank you.

11

InDesign manifest documentation says there is no need for . dot. But Photoshop manifest documentation do has a .

https://developer.adobe.com/indesign/1688653963277/plugins/concepts/manifest/#launchprocesspermission

https://developer.adobe.com/photoshop/uxp/2022/guides/uxp_guide/uxp-misc/manifest-v5/#launch-process