Aliasing a File URL

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files_folders
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#1

What for?

Many text-handling programs allow you to drag (or paste) a file into their text field, in order to create a file URL that points to that file.

The problem with this is: Unlike Finder Aliases, file URLs are fragile. They behave like absolute symlinks, that is, they immediately break if you do one of the following:

  • Modify the file name
  • Move it to another folder
  • Modify the name of any of the file’s parent folders
  • Move any of the file’s parent folders

The macro facilitates you to create “aliased” file URLs that will not break if you do one of the above things.

Obviously this is not much needed for rather “static” files, for example files in archived folders, which are unlikely to change.

However, it can be very handy for anything in the context of a work-in-progress project, that is, where file and folder names/paths are subject to potentially frequent change.

Example:

  1. You create a draft of a text and put it into the “Drafts” folder inside your project folder.
  2. Then you create a note “Add ‘blablabla’ to the draft” in your task manager (for example Things or TaskPaper), followed by a link to that draft file.
  3. The project progresses, and later on you decide to rename your “Drafts” folder to “Drafts – Chapter 01”.

If your link to the draft file was a regular file URL, then that link is broken now. Instead, if you’d created the link with this macro, it would still be working.

Background

For most things I’m using Things as my task manager (sometimes TaskPaper). Up until recently Things had a really superb and outstanding feature: If you dragged a file to Things, Things stored the link to that file as alias data inside its database. The link in Things behaved exactly like a Finder Alias, i.e., pretty hard to break.

For some opaque reasons they decided to remove that feature, and a file dragged to Things now creates an ordinary file URL. Just like in TaskPaper and other similar apps. So I was looking for a solution, and this macro is the best I can come up with, ATM.

Basically just trying to replace the bygone feature of Things, but the macro is also usable with other apps.

How it works

  1. The macro creates aliases of your Finder-selected files/folders at a pre-defined location.
  2. It gets the file URL and the file name of these aliases and puts this info in a formatted form to the clipboard.

How to use

  1. Select the file(s) or folder(s) you want to link to in the Finder.
  2. Run the macro.
  3. Go to your task manager (or any other text-handling app) and paste.

Result (example with Things):

09-pty-fs8

Normal result of dragging a file (without macro):

24-pty-fs8

Note: In contrary to what the images might suggest: The point is not to make the file URL shorter. It’s a side effect.

Tips

Location of the alias hub

You can set the location where the alias files will be stored (the “alias hub”) in the contained AppleScript.

Choose a short folder name and a short path, in order to get a compact URL. The default is set to “alias” at the root of your Home directory. (~/alias/)

Link format

The script is set to paste a link in the format
<file name><separator><file URL>

You can change the separator in the AppleScript. For a newline use linefeed (not quoted).

Caveats

Duplicate file names

If you create a file alias that already exists in the alias hub directory, it will be created with an “alias” suffix (and later on with “1”, “2”, etc.). This is the Finder’s usual behavior. This might not be optimal, but I think it is quite OK, as it makes sure that you always get a working alias and at the same time you are adverted of a possible redundancy.

The aliased file URL will be created correctly, no matter how many duplicate aliases you create.

Aliases can break too

Aliases are pretty robust to path/name changes. But they can break, too. If this happens, then you would be better off with a regular file URL, since it provides a clue to the last file location before it broke.

An option would be to append the literal path of the source file at the time of creation to the link. But, I think, the resulting link text would just be uncomfortably longish for the 97% of the cases where the alias does not break.

The macro

Compared to my description the macro/script is very compact :slight_smile:

Set the hotkey to your needs.

Alias File URL.kmmacros (3.0 KB)

The script content of the macro:

  # Some settings
  # The location where the aliases should be stored. Use a short name and path to keep the URL short.
  set aliasHub to (path to home folder from user domain as text) & "alias"
  # The filename/fileURL separator for the URL display
  # For example " — " will create this: "Test File.txt — file:///Users/tom/alias/Test%20File.txt"
  set theSeparator to " — "
  
  set niceURL to {}
  
  tell application "Finder"
    # Create aliases from the Finder selection in the alias hub
    set theSelection to the selection as alias list
    set theAlias to (make alias at aliasHub to theSelection) as list
    # Get properties and construct a nice file URL
    repeat with i in theAlias
      set {theName, theURL} to {displayed name of i, URL of i}
      set the end of niceURL to theName & theSeparator & theURL
    end repeat
  end tell
  
  # Put it to the clipboard as text
  set {saveTID, AppleScript's text item delimiters} to {AppleScript's text item delimiters, {linefeed}}
  set the clipboard to niceURL as text
  set AppleScript's text item delimiters to saveTID

I guess the script could also be made as a pure/native KM macro, but it is an AppleScript, because initially it was created for use with LaunchBar.

Notes

Above I often mentioned apps like Things and TaskPaper, but the script of course will also serve when pasting into any other app that can handle text.




Addendum 2019-05-15:

A different approach

Another approach, to achive basically the same, is by using file reference URLs.

A file reference URL looks like this:

file:///.file/id=6571367.8706809504

Instead of the file path (as with a normal file URL) it contains the inode number of the file (the “8706809504” in the example above). The first number is likely some volume identifier.

Here a variant of the above script that will copy the file reference URLs of the Finder-selected items to the clipboard (along with the file name, as in the script above):

use AppleScript version "2.4" -- Yosemite (10.10) or later
use framework "Foundation"
use scripting additions

# The filename/fileURL separator for the URL display
# For example " — " will create this: "Test File.txt — file:///.file/id=6571367.8706809504"
set theSeparator to " — "

set niceURL to {}

tell application "Finder" to set theSelection to the selection as alias list
# Get properties and construct a nice file ref URL
repeat with i in theSelection
  tell application "Finder" to set {theName, thePath} to {displayed name of i, POSIX path of i}
  set theURL to (current application's class "NSURL"'s fileURLWithPath:thePath)
  set theRef to theURL's fileReferenceURL()
  set theRef to theRef's absoluteString()
  set the end of niceURL to theName & theSeparator & theRef
end repeat

# Put it to the clipboard 
set {saveTID, AppleScript's text item delimiters} to {AppleScript's text item delimiters, {linefeed}}
set the clipboard to niceURL as text
set AppleScript's text item delimiters to saveTID


File Reference URL.kmmacros (3.1 KB)

Pasted into Things it looks like this:

00

Advantages

  • More elegant; you don’t have to create an “alias hub” folder on disk.
  • The resulting URL is likely to be shorter than a file URL

Disadvantages (?)

  • The only reference to the file is the inode number. So, I’m not sure if it is as reliable as an Alias.

    • The bookmark data inside an Alias also contains the inode number, but in addition much more information on the destination file; for example the original path, which gets updated – at least – each time you resolve the Alias.

    • On the other hand, I’m not sure if an inode number can break at all (?). And if it breaks, I’m not sure if the Finder would make good use of of the other bookmark information contained in an Alias, in order to locate the “missing” file. [1]

  • Not much tested.


1: One case where a mere file reference URL will fail (because the inode changes) and an Alias should/could continue to work, is when you move your whole folder hierarchy (including Alias and destination file) to a different volume. For this to work it seems to be required though that the path info inside the Alias is up to date before moving the files. (Either by double-clicking or using a tool to batch-resolve Aliases.)