Detecting favicons in Yoink v3.3

One of Yoink v3.3‘s new features is the detection of favicons for webloc files dragged into the app, making it easier to quickly identify individual weblocs at a glance. (A webloc file is something Finder creates when you drag a URL/link to it).
Think of it as QuickLook icon previews, just for websites:

Yoink with webloc files without favicons

weblocs without favicons

Yoink with webloc files with favicons

weblocs with favicons

The advantage is obvious right away, that’s why I jumped on it the second the feature was suggested to me.

Optional Setting

Even though I really like favicon detection and have it enabled on my Mac, I decided right at the start that favicon detection would be opt-in (disabled by default), for a couple of reasons:

  1. It requires an internet connection
  2. It uses data (very little, but still)
  3. I thought I’d use a Google Service for this (which I discarded after the prototype) and wasn’t comfortable having users use it without their “consent”

1) Internet Connection

Yoink is not an app that should require an internet connection at all.
It’s a “local” Mac app, it helps you with drag and drop, why need an internet connection?

As a side note, the connection itself actually doesn’t happen in the main Yoink app, it’s an XPC service that has the sandbox privilege, so the main app isn’t affected.

2) Data Volume

A Mac usually connects to the internet over WiFi or an Ethernet connection, and the data transferred for favicons *is* very small.
But there’s still a chance you’re using weblocs like crazy on a Mac connected to the internet via your iPhone’s Personal Hotspot on a data plan, which also makes it obvious why the user needs to be able to turn this option on and off.

It just made me more comfortable to have users opt-in to this option, instead of opt-out.

3a) Google?

Google has a nice favicon detection service, which is just a URL you pass another URL into to receive the image data:

There’ no need to parse the HTML yourself for the URL to the favicon, Google does it all for you.

3b) So Why Not Google?

What if the service goes away?
With Google having a bad rep for some users, would they use this feature?
What about privacy? (I don’t know, but they might collect your IP and then know what URL a favicon was loaded for, etc.)

So even though it worked very nicely, I decided to implement it myself.

Getting the Favicon

With Google out of the picture, I had to roll my own detection and parsing.
What I do is actually very, very simple.

I load the webloc’s URL’s HTML content, and then look through the header part.
In particular, I look for one of the following lines:

rel=“shortcut icon”

in that order. (I’m sure there are more I could go through, but those were the ones that I came across while testing.)
Should none of those exist, I just try something like:

•) http:// … /favicon.ico
•)  …/favicon.png
•) rinse and repeat for every image format you can think of

If I have no luck there, either, I bail and return macOS’ default webloc icon.

If I am lucky and I find a “rel” I’m interested in, I figure out what the href contains (an absolute link to the image, a relative path to the image, or just the name of the image file itself). Once I know that, I can load the image file and composite it into the final icon.

The final icon is cached so Yoink won’t have to connect to the internet and re-download favicons for weblocs that point to the same base URL.

Drawing the “personalized” webloc icon

I went through three iterations, each at its own, unique laziness level.

Iteration 1, laziness level 3 (extremely lazy)

Just show the favicon:

Iteration 1 of Favicons in Yoink

No wonder I didn’t use it. It’s so lazy.
Second, it doesn’t even remotely resemble a webloc file anymore. It actually looks more like an image file’s QuickLook preview icon, and that’s a bad thing, as it could very possibly confuse users.

So I went on to

Iteration 2, laziness level 2 (pretty lazy)

Show the favicon super-imposed on the webloc icon:

Yoink Favicon Icon Iteration 2

That’s better. But not good, either. Favicons can be transparent, like the one here, but they can also be opaque, blocking the WEBLOC text in the icon and making the overall icon look more blocky and less nice.

Onwards and upwards!

Iteration 3, laziness level 1 (not that lazy)

Crop out the “Safari” part of the webloc icon and paint the favicon below it:

Yoink Favicon Icon Iteration 3

If the favicon is transparent, I draw it on top of a white background (so it would fit with the rest of the original webloc icon), if it’s not transparent, the favicon’s background is used, solving everybody’s problems. And you can still see that it’s a webloc file, at first glance!

Eternal Storms Software Logo

– – – Do you enjoy my blog and/or my software? – – –
Stay up-to-date on all things Eternal Storms Software and join my low-frequency newsletter (one mail a month at most).
Thank you :)

Mac Developer Tip: Programmatically Starting a Search on the Mac App Store

Working on Transloader 3, I wanted to re-implement the Finder’s Open With… contextual menu:

The Finder's Open With contextual menu

Getting the apps in there turned out to be the easy part. What took some effort was the “App Store…” menu item, as I wanted to precisely replicate its functionality.

Transloader 3's Open With contextual menu

Right-click a file in Finder, select Open With -> App Store…, and it will launch the Mac App Store with a UTI search, for example:
This will give you a list of all apps available in the Mac App Store that can handle that file type. Neat!

The ‘macappstores’ URL scheme

The Mac App Store app luckily offers a URL scheme:

  • macappstores://
    Launches the Mac App Store
  • macappstores://showUpdatesPage
    Launches the Mac App Store and takes you directly to your Updates page
  • macappstores://showPurchasesPage
    Launches the Mac App Store and takes you directly to your Purchased page
  • macappstores://
    Launches the Mac App Store and takes you directly to the product page, identified by the product ID

That’s very practical, but not what I was looking for. I was in need of a way to start a search the way Finder does.

In order to find out the URL Finder uses, I wrote a quick throwaway-app that would overtake the Mac App Store’s URL schemes (using LSSetDefaultHandlerForURLScheme) and print out the URL that was opened.
Alas – no dice. Apparently, Finder uses Apple Events or some other magic that “can not be used in a third-party sandboxed app anyway”™ to do its bidding.

After googling the issue, I found a URL that supposedly worked: macappstores://, but just to pour more salt into an already wide-open wound, it only worked on pre-10.9 systems:

The search URL in 10.9-and-beyond systems

Another dead end. Or was it?
I guess I should have experimented with that URL a little, because Jan Vitturi (@jan4843 on twitter) had the answer: just remove “ax.” from the URL, and it works (on both pre-10.9 and post-10.9 systems)!

Using this URL:
I was able to get a search going on the Mac App Store, right from within my app.

Sadly, there’s a caveat.
I can’t do a UTI search this way. When I pass (even a percent-escaped) search term along the lines of ‘’, the Mac App Store tells me there are no results. Reloading that very same page then does show the results – weird and annoying, but nothing I was able to work around.
Using extension:zip seemed to work a little better, but still didn’t return all results a reload would.

Jan Vitturi to the rescue again – the URL’s a little different for UTI or extension searches:

Alternatively, instead of uti=…, you can use extension=… to search by file path extensions.

My sincere thanks go to Jan Vitturi!


Eternal Storms Software Logo

– – – Do you enjoy my blog and/or my software? – – –
Stay up-to-date on all things Eternal Storms Software and join my low-frequency newsletter (one mail a month at most).
Thank you :)

Mac Developer Tip: NSTouchBar in a Share Extension

You’re working on your Share extension with support for MacBook Pro’s Touch Bar, but it’s empty and doesn’t appear when your extension is loaded?

NSTouchBar Empty

The solution is simple:

Solution for showing NSTouchBar from within a Share extension

Call [self.view.window makeFirstResponder:self.view]; and it will push your glorious NSTouchBar onto the stack:

NSTouchBar working in a Share extension

Hope it helps – it would have saved me 20 minutes if I’d known ;)

Eternal Storms Software Logo

– – – Do you enjoy my blog and/or my software? – – –
Stay up-to-date on all things Eternal Storms Software and join my low-frequency newsletter (one mail a month at most).
Thank you :)