Connectivity Still an Issue

A cloud-centric approach is destined to deliver a subpar user experience because the access to the cloud isn’t ubiquitous, and it won’t be for a long time. Ubiquitous is a very high bar. For example, although I’m in a 3G coverage area, there are many (Wifi-free) buildings I could enter where the signal doesn’t reach my device.

If my device was useless whenever it couldn’t connect to the cloud, I would be very frustrated with it.

Storage Continues to Beat Bandwidth

Disk space is getting cheaper faster than bandwidth is getting cheaper, and it has been for many years. Flash-based storage, while not dropping in price like spinning disk drives, is also getting cheaper faster than bandwidth.

Even worse, bandwidth has been actually getting more expensive in many scenarios because of data caps. If your usage pushes you over your monthly data cap, it often gets very expensive very quickly.

Store Locally, Transfer Globally

The sensible thing to do given these trends is to store things on the device whenever possible. Things stored on the device are available no matter what, with no latency. This might not make sense today for data-intensive applications like video where the device’s storage is currently too small, but storage prices will continue to fall rapidly.

The internet is great as a transfer mechanism but too expensive, slow and unreliable to be the primary data source for many applications.

Searching the net gave me some clues, like I should subclass the cell that the NSBrowser uses and call [NSBrowser setCellClass:], but searching also led me down some fruitless paths. Contrary to what you may have read, don’t subclass NSBrowserCell — it’s unsubclassable.

Finally I stumbled on Apple’s ComplexBrowser sample code. It uses a subclass of NSTextFieldCell. And it gives some clues on how to capture the checkbox click.

The Code

When I began my search, I was hoping to find someone’s sample project that did just what I wanted, but no luck. So I’m publishing my sample project for the next person who goes looking for such a thing:

https://github.com/sreitshamer/FSBrowser

Enjoy!

- Stefan

So, I wrote a simple utility called appversion which prints the value for the CFBundleVersion key in an app’s Info.plist.

For example:

	appversion /Applications/iPhoto.app

yields:

	8.1

Download the 32/64-bit Universal binary (in a zip file) here:

appversion.zip

So, Arq needs its own “crash reporter”. After reading Daniel Jalkut’s nice roundup of crash reporters, I chose Breakpad because it seems the most similar to Apple’s built-in crash reporter.

Adding Breakpad to your Mac OS X app is easy since the Breakpad team created a Framework around it.

Building Breakpad

Just download the source, open the XCode project under src/client/mac and compile the target “All”.

If you’re on 10.6 though, you’ll need to set the compiler for all the targets and sub-projects to “GCC 4.0″, or else you’ll get an error “GCC 4.2 is not compatible with the Mac OS X 10.4 SDK”.

The default settings for the project (at least as of svn revision 394) create a “32-bit Universal” build. 64-bit isn’t supported yet. See the Breakpad issues list for more details.

Adding Breakpad to Your App

Once you’ve built Breakpad, drag Breakpad.framework into the Linked Frameworks folder of your XCode project. Be sure to check the “copy items into the destination group’s folder” box in the sheet that appears. Also check the target you want to add Breakpad to.

Next, create a “Copy Files” build phase in your target with a destination of “Frameworks”, and drag Breakpad.framework into that.

Next, add a bunch of variables to your app’s Info.plist, including:

	BreakpadProduct
	BreakpadProductDisplay
	BreakpadVersion
	BreakpadVendor
	BreakpadURL
	BreakpadRequestComments

See the comments in Breakpad.h for how to set those variables. One tricky bit: BreakpadRequestComments should be a <string> with a value of "TRUE" in your Info.plist, not a <true>.

As an example, here’s how I set my plist variables for Arq:

    <key>BreakpadProduct</key>
    <string>Arq</string>
    <key>BreakpadProductDisplay</key>
    <string>Arq</string>
    <key>BreakpadVersion</key>
    <string>1.1</string>
    <key>BreakpadVendor</key>
    <string>Haystack Software</string>
    <key>BreakpadURL</key>
    <string>http://crashreport.<yourserverhere>.com/arq/new</string>
    <key>BreakpadReportInterval</key>
    <string>0</string>
    <key>BreakpadLogFiles</key>
    <array>
        <string>/var/log/system.log</string>
    </array>
    <key>BreakpadLogFileTailSize</key>
    <string>40000</string>

Finally, create a Breakpad object in your app:

    BreakpadRef bp = BreakpadCreate([[NSBundle mainBundle] infoDictionary]);
    if (bp == NULL) {
        NSLog(@"failed to create Breakpad");
    }

That’s it! Now crash your app to try it out

On the server side, you’ll need something to process the report. I’ll post my server-side code soon. Tweet me @reitshamer if you need it right now.

UPDATE: I put the server-side code at http://github.com/sreitshamer/breakpadserver.