Solipsism Gradient

I just found out that an errant script is messing up the automatic version checker in Quay and Klicko – a consequence of the server migration which happened several days ago. Please hold on while our trained server gnomes return from their burrows and fix it (it might be one or two more days, I’m really stretched thin here). My apologies.

Update: fixed. Again, sorry about the delay.

While reading the links pertaining to the previous post about a “back” button for the iPad – and, incidentally, for the Mac – it occurred to me that such a capability might be built into a future version of my Klicko utility. Which is Mac-only, of course. For now, Apple doesn’t allow any sort of utilities for the iPhone/iPad, more’s the pity.

I’m rather overloaded at the moment, moving out of my apartment only a few days before going off to WWDC, and I’ve got an iPad app prototype to work on, too; but I’ll definitely look into this as soon as possible. I think that most of the infrastructure, in fact, is already in place inside Klicko.

I did download the Universal Back Button App, but didn’t have time to check out how it works; at any rate, it seems to be quite different in implementation.

Brent Simmons, author of NetNewsWire, writes:

On Macs we have a long-standing culture of apps working together.

…

On the iPad (and iPhone) we can sort-of do the same thing. We don’t have AppleScript or Apple events, but we do have the URL scheme thing for inter-application communication. It’s technically possible to do some of these same things.

But we don’t have an easy way to get back to the calling app.

…

What if the calling app added, as a parameter to the URL, a URL to call when the task is completed?

This way the helper app (NetNewsWire in this case) would know, once the task is complete, how to get the user back to their place in the calling app (Twitterrific in this case).

I was thinking about the same issue, coincidentally, and one idea which occurred to me is to use the equivalent of the http referrer URL (often misspelled as “referer” for historical reasons).

For  a standard http request the referrer is the URL of the document containing the clicked link, so you can get back to that document by clicking on your browser’s “back” button. Now, this isn’t really contained in the URL itself – rather, the browser appends this as one of the fields in the http request headers – but the analogy is interesting.

For this to work locally between applications, the referrer URL would need to be set into the URL targeted at the called application. And indeed, there is a -[NSURL setResourceValue:forKey:error:] method that, in theory could add any key/value pair to the URL. (Currently only the “scheme” property seems to be available, though.)

Update: Mike Abdullah points out in the comments that, in practice, this method applies properties to the file a file URL points at, not to the URL itself. Drat.

On the receiving side, the “referrer” value would have to be pulled out from the NSAppleEventDescriptor that the application gets with the ‘GURL’ event.

All this needs filing enhancement requests and Apple would have to do the required twiddling inside their code base – or rather, bases, as this would be useful to have both on the iPhone/iPad and the Mac side. It would take a long time, if it’s done at all.

The alternative would be to developers to, informally, establish a convention for incorporating this into the URL itself. So we’d have something like:
calledscheme:///the/url/parameters&?REF=callingscheme://some/url/to/return

Probably the second part would have to be suitable encoded/escaped, too. Maybe this would be a good topic for discussion at WWDC?

Interesting piece by Sean Heber aka BigZaphod.  Remember my post about the significance of Clang/LLVM on the iPad?

I think there’s a chance that Apple is slowly building Objective-C into a managed environment similar to Java/.NET. At some point in the future they could define an Objective-C HD (or whatever :P) that no longer maintains total compatibility with C. Since they use LLVM a lot now, they can even use that to analyze your code to make sure that pointer accesses are safe and controlled. Anything that isn’t safely confined to your own app would be an error. Access to the Objective-C runtime functions could possibly even be revoked. After which point, Objective-C HD no longer compiles to machine code but instead to an intermediate representation.

By doing something like this, they can abstract the actual underlying CPU hardware and architecture out of the applications themselves as well as maintain a truly safe sandbox where private and undocumented APIs simply will not be allowed to work. Apps on the App Store would be submitted in this intermediate format which they can translate into the machine code that’s native to whatever CPU happens to be in the device you’re downloading the app for or they could simply put a JIT in iPhoneOS (although there’s no reason to waste the CPU cycles on the device if they can translate them once on the backend – at least for mobile stuff).

Pretty much complementary to my reasoning.

Just published a droplet application that fixes the spelling error in nibs produced by my previous (beta) version of the RBSplitView Interface Builder plugin. Details on the RBSplitView page.

So, to start things going again… I was looking at my RSS feeds for the first time in almost 5 months, and read Dan Wood of Karelia fame explaining about Converting Rich Text to TEXT/styl resources for an SLA on a Disk Image.

My own workflow for building a release disk image uses a small tool I’ve written for that. You can download it here. Here’s the help text it prints out if you run it without arguments:

   Add one license at a time to a (unflattened) disk image.
   Usage: AddLicense /path/to/TheUnflattened.dmg Language /path/to/TheLicense.rtf
   Languages supported: da nl ko ja fr it fi pt sv en es de nb
   You can also use long equivalents like English, French etc.
   The first language added will be the default language (usually English).

Here's an actual usage example from a build script:

   hdiutil unflatten "$SOURCE_ROOT/My.dmg"
   "$BUILT_PRODUCTS_DIR/AddLicense" "$SOURCE_ROOT/My.dmg" English "$SOURCE_ROOT/EnglishLicense.rtf"
   "$BUILT_PRODUCTS_DIR/AddLicense" "$SOURCE_ROOT/My.dmg" French "$SOURCE_ROOT/FrenchLicense.rtf"
   hdiutil flatten "$SOURCE_ROOT/My.dmg"

and I use the “flatten” and “unflatten” arguments to hdiutil to massage the disk image.

The trick (as Dan points out in his post update) is that you can use ‘RTF ‘ resources instead of TEXT/styl. I received this interesting tidbit through oral tradition; I’m not a 100% certain, but I think it was through some code that Marko Karppinen showed me a few years ago. Pass it on.

If there’s interest, I may clean up and publish the source sometime, though it uses all sort of gronky old APIs (Resource Manager etc.).

Update: the link above now downloads the complete Xcode project. I also included it on my source code page.

I just published the Xcode project for the AddLicense tool I mentioned previously. Enjoy.

Posted by 0xced:

Rainer Brockerhoff wrote:

If there’s interest, I may clean up and publish the source sometime, though it uses all sort of gronky old APIs (Resource Manager etc.).

Oh yes, there is interest!