Magic Launch: Take Back Control of File Associations

Apple made a controversial change in Snow Leopard. It’s a fairly system-level one, though, so perhaps the majority of users will not have had any issues with it – but it’s made some experienced Mac users pretty unhappy. What’s changed is the way in which files open when double-clicked.

It used to be that OS X embedded what’s known as a Creator Code in new files, so that the system knew to open files within the applications that made them. Rob Griffiths published a discussion of this behaviour, and the changes in Snow Leopard, in Macworld back in September last year. Have a read of that piece, and the lengthy comments that accompany it, if you want to understand the issue better.

I haven’t been impacted by this change to a great degree, but one of the applications that comes up in discussion of ways of fixing the change, and giving back more control over what applications open files, caught my eye. Michel Fortin’s Magic Launch is a Preference Pane that lets you manipulate file-opening in ways that allow you a great deal of flexibility.

It solves the problem of Creator Codes being removed, but it also adds some excellent functionality, and that means it’s well worth a look even if you’re untroubled by the main issue it addresses.

What It Is, What It Does

Let me begin by saying again that I’ve really not been affected by this change in Snow Leopard – I probably wouldn’t even have noticed it, had I not chanced on that Macworld article a while back. But I find that Magic Launch allows me to do some really useful things, and so I’m glad to have discovered it. It scratches an itch I didn’t even know I had.

For those bothered by the removal of Creator Codes, the problem is that Snow Leopard opens, say, HTML files created in TextMate, in the default browser, rather than in TextMate, which is a far more sensible editing environment. Magic Launch immediately fixes this, by interposing itself in the file-opening process.

Magic Launch is a tiny download, and installs as a Preference Pane under your System Preferences.

Magic Launch in Preferences

Magic Launch in Preferences

Open up the Pane, and you’ll see this – a simple setup screen:

Setup Screen

Setup Screen

Remember that the core function of Magic Launch is to be able to configure and control which applications open particular files. So if you have a file that you want to set up, you can simply drag-and-drop it into the main window, and Magic Launch will recognise the file extension, and if it can, identify any variants of that type of file. For instance, if you drop a plain text .txt file, Magic Launch knows to add to the list files with the .text extension.

And then you simply select from the Default Application pulldown menu which app you want to use to open files of this particular kind.

Selecting an Application

Selecting an Application

The next time you double-click on a file with that extension, regardless of what application you used to create it, it will open with the application you’ve selected here.

Another Use

Another use that immediately comes to mind is fixing things after you’ve installed a particularly aggressive application that claims all files of a particular kind., for instance, the last time I installed it, set itself to open all Microsoft PowerPoint files, when I wanted them to be opened by Keynote. This is easily fixed by ctrl-clicking on the file and then selecting ‘Get Info’ (or selecting it and then hitting [cmd]+[i]) and then altering the ‘Open With’ setting:

Finder Application Choice

Finder Application Choice

But installing another application might again claim the file-type for itself. Whereas, if you have Magic Launch installed, you can set the groundrules here, and no amount of meddling from other apps will change your preference.

Clever Stuff

But what really interested me about Magic Launch is its ability to do some clever things, which I think could really help fine-tuning one’s workflow.

Here’s an example from my own setup: For the last year or so, I’ve done all my writing in TextMate, and that’s definitely the app I choose for any other work involving text files (and, for simplicity’s sake, I now keep most of my information in plain text). Recently I took another look at Writeroom, and I’m really enjoying using it as my main writing environment (got to love that typewriter scrolling!).

So when I’m working on a piece, I want the file to open in Writeroom, but once I’m done, I’m happy to hand it back to TextMate. All I needed to do was introduce a new convention: I now start working file titles with the word ‘draft’, and have set up a rule in Magic Launch that any text file that includes that word opens in Writeroom.

Creating Rules

Creating Rules

When I’m done with my editing, I remove the ‘draft’, and in future the file will open in TextMate, along with all the other text files on my system.

Now that’s a really simple implementation, but it meets my needs. Your situation may be far more complex, and you might be working with a much wider range of file-types through the day.

One example might be those who work with image files – you spend your time creating a high-resolution graphic, but when you want to take a look through a bunch of these, you don’t really want to have to fire up Photoshop.

You could create a rule in Magic Launch that does different things with files with different phrases in their titles, as above, or you could use different colour Labels – when you’re done with editing an image and move it into a store folder, you could set the label to red, and your Magic Launch rule would then open red-labelled files in Preview.

Image Previews

Image Previews

You could rope in Hazel to make this process even easier: just set a rule in Hazel that files dropped into a particular folder are labelled red, and you’re done.

In Conclusion

Using the familiar rule-setting logic in Magic Launch means that you can define and refine how files are treated by a wide range of criteria. I know, I know, I know that there are other ways of doing much of what this app can do, but I love that it makes the process so easy and straightforward.

You can set up your file-associations and rules, and then forget about Magic Launch: it’ll quietly, simply get on with its job, and after a while you’ll quite possibly forget that it’s there.

To my mind, that’s the best kind of tool: one that gives you power and granular control, and then gets out of the way so that I can get on with doing the things that are important to me.


Magic Launch is a preference pane that lets you customize the experience of opening files on your Mac. It’s something you do often, so it deserves to be hassle free!

  • Michel Fortin

    By the way, Magic Launch is on sale with 35 % off until the end of August.

  • Yaro
  • Stanley

    Looks great! While Mac OS X contains some wonderful technology, its system of filetype association has always been a confusing, inelegant throwback to the DOS era.

  • Ryan

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  • gaf

    seems like just as much time is spent fiddling with the files names, labels etc.. (which also requires you to right click the file to change the label) when you could have spent less time with just 1 “right click>open with>(app)” and no messing inside of “Magic Launch”

    Thats JMO though.