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11
Apr

Introducing FastSocket

FastSocket is a fast, synchronous Objective-C wrapper around BSD sockets for iOS and OS X. Use it to send and receive files or raw bytes over a socket very quickly. This is the class to use if fast network communication is what you need. An asynchronous API might be better if you want to do something else while your network operations finish.

UPDATE: Now available as a CocoaPod

I wrote FastSocket a couple years ago, and put it up on GitHub, but don’t think I ever mentioned it. There are classes for both clients and servers. It’s available under the MIT license. Please feel free to let me know if you have any problems, questions or suggestions.

To create and connect a client socket:

FastSocket *client = [[FastSocket alloc] initWithHost:@"localhost" andPort:@"34567"];
[client connect];

Send a file:

long sent = [client sendFile:@"/tmp/filetosend.txt"];

Receive a file of a given length:

long received = [client receiveFile:@"/tmp/newlyreceivedfile.txt" length:1024];

Send raw bytes:

char data[] = {42};
long sent = [client sendBytes:data count:1];

Receive raw bytes:

char data[42];
long received = [client receiveBytes:data limit:42];

Close the connection:

[client close];

Please check out the unit tests for more examples of how to use these classes.

21
Mar

Moving Away From FeedBurner

Just a quick note. I’ve been using FeedBurner to handle my RSS feed. If you are subscribed to my blog using RSS, you will need to resubscribe to the new address. I apologize for asking you to do this, but it looks like FeedBurner may be shutting down soon. Thanks!

17
Oct

Automatic Build Numbers for iOS Apps Using Xcode

UPDATE Sep 2014: Added another idea from Jared Sinclair, who has example code for Git.
UPDATE Jan 2013: Now also updating the build version in the dSYM file.

There are many articles that discuss how to automate build numbers in Xcode. However, some are misleading for iOS apps. Many are quite long. I wanted to find a short, simple way to do this.

Background

On the target Summary tab your project settings, Xcode lets you set a Version and a Build. The version is what we are all familiar with, such as 5.0 and 5.1.1. The build is what often appears in parentheses after the version, as in 5.0 (134) and 5.1.1 (147).

Apple doesn’t seem to care what you use for Version (aka CFBundleShortVersionString), but Build (aka CFBundleVersion) must be a monotonically increasing string, comprised of one or more period-separated integers. Thus Apple will reject your update if you go from 1.1 (10) to 1.2 (0). The version is ignored and, alas, zero is clearly less than ten.

The part about integers is important too because Apple will also reject your update if you go from 1.01 (1.01) to 1.1 (1.1). The period is not a decimal place. Both (1.01) and (1.1) are interpreted as “the integer one followed by the integer one”. We saw this logic in action when OS X went from version 10.4.9 to 10.4.10.

Problem

If you do this wrong, you’ll see this error when you upload your app update:

This bundle is invalid. The key CFBundleVersion in the Info.plist file must contain a higher version than that of the previously uploaded version.

To get your monotonically increasing period-separated integer build number, you could just use the app version, like 5.1.1 (5.1.1). But I think it’s better to use a build number that can help identify the code from which that version of your app was built. Both Git and Mercurial include the ability to count commits, which is perfect—always increasing and helpful in identifying the code.

If you modify the Info.plist file in your project folder during the build process, you’ll probably need to commit the change to your code repository. This extra commit, while not harmful, is unnecessary. Instead, you can modify the Info.plist file in the app package after the build process is finished. The file will be in a binary format, but the PListBuddy tool can handle it.

Solution

Here is the script you need for Mercurial. This script also adds the bundle version to the dSYM file, which is necessary for correctly symbolicating your crash logs. It’s also required for several distribution mechanisms including TestFlight and HockeyApp.

ver = `/usr/local/bin/hg id -n`.strip
puts "Build number is #{ver}"
filepath = "#{ENV['BUILT_PRODUCTS_DIR']}/#{ENV['INFOPLIST_PATH']}"
puts "Updating #{filepath}"
`/usr/libexec/PlistBuddy -c "Set :CFBundleVersion #{ver}" "#{filepath}"`
filepath = "#{ENV['DWARF_DSYM_FOLDER_PATH']}/#{ENV['DWARF_DSYM_FILE_NAME']}/Contents/Info.plist"
puts "Updating dSYM at #{filepath}"
`/usr/libexec/PlistBuddy -c "Set :CFBundleVersion #{ver}" "#{filepath}"`

The first line counts the number of commits in your local repository. It’s safe to use as long as your builds are done on the same machine. Repositories on other computers may have different commit counts. For Git, you can count your commits using a similar command.

Steps

  1. Select your project in the Project Navigator
  2. Select your target
  3. Select the Build Phases tab
  4. Choose “Add Build Phase”
  5. Select “Add Run Script”
  6. Change the Shell to “/usr/bin/ruby”
  7. Copy and paste the script

Within your app, you can grab the version and build number with this code:

NSDictionary *appInfo = [[NSBundle mainBundle] infoDictionary];
NSString *appVersion = [NSString stringWithFormat:@"%@ (%@)", appInfo[@"CFBundleShortVersionString"], appInfo[@"CFBundleVersion"]];

This will give you a string like 2.2 (134) that you can display in your app. I’m using the new object subscripting syntax in Objective-C, but it’s not too hard to switch back to using objectForKey:.

Follow Up

Jared Sinclair has a nice example of how to do this with Git. I really like the idea of using the branch name as a build suffix for Debug builds. I’m going to update my code to match.

10
Oct

Information on the Internet Lives Forever

I bought a mattress a while back and a bad experience with one of the products I purchased. The company handled the return much more gracefully that I was expecting. As I wrote up my experiences with the whole mattress buying experience, I mentioned my mixed experience and moved on. I didn’t think much more about it.

Until the owner of the store called me. We were both a little tense. I was worried about threats and lawsuits, and he was worried I’d be a jerk. He was losing some business from people who’d read my article. Yay for blogger justice! But his concern was correct because information lives forever on the Internet.

He could have fixed the problem, or switched to a new supplier, or discontinued that product, or even gone out of business, and my article would remain. I’m glad he called. He was nice, and I’m glad to have the opportunity to keep my article current.

Information on the Internet lives forever. Unless you want to find something cool you know you read several years ago, of course. Then it’s probably gone forever. I just try to keep up.

11
Sep

My Best Stuff

You may have noticed the new My Best Stuff section on the side. The articles there either continue to be the most viewed or have generated the best reaction from people who know me. I didn’t think much about it when I was calling it Popular or Recently Popular. Calling it “my best” makes me nervous.

It made me realize that those articles probably do represent my best writings, or at least my most successful. And I wonder if they’re actually any good. No real way to find out, except by forging ahead anyway.

So please don’t hesitate to let me know if I’m wrong about what to include in the list or if you have any comments or suggestions. You can follow me on Twitter here or email me .

I’ll update the list on occasion as I discover which articles resonate with people the best.

4
Sep

My Current Project

A few months ago, two friends asked if I’d be interested in working on a book project with them. Jed is a successful artist and illustrator. Noelle is a brilliant writer and educational designer. They’ve worked together on several projects and wanted a programmer to help design a book app. I said yes before they stopped talking. :)

Here is one of Jed’s early designs:

Story app mock up

It’s an interactive fiction fantasy story app, except that the plot is cohesive and targeted at a young adult audience. In many choosable path books, the endings were often very different from each other. For example, the plot might change from bank robbers to aliens depending on which door you went through. Also you died a lot.

In our story app, you nudge the main character in the direction you want her to go even as the story unfolds around her. The book remembers the choices you make and adjusts the text and artwork as you go along. Noelle is writing the same story more than 20 times and loving it. She’s been planning this story since high school.

A website is coming soon. We’re close to finishing the programming, art and writing for chapter one. Noelle is wrapping up chapter two in a few weeks.

Jed recently completed a successful Kickstarter project for traditional hand-made Japanese woodblock prints of video game characters. It’s kinda cool, so check it out if you’re interested.