I took picture [Train Station Edition]

Grand Central Station, Manhattan, New York, NY

i took a picture [Rastaman edition]

Montego Bay, Jamaica 2011

Making UIImages with blocks

So i was going to post about something completely different today, but as i was typing i looked at my code, and thought it was verbose and a little bit ugly.

So i made it awesome, and as everyone knows to make your code awesome you add some blocks to it.

My problem was simple, i was faced with the need to create two CGBitmapContext, for the uniformed the following code is required to prepare a bitmap context for drawing.


So after a bit of thought, i decided what i really wanted was a method that did all of this for me, and meant that i didn't have to worry about constantly checking the code for leaks (DRY), and that was pleasant to look at and i came up with the above. The block that you pass in is given a fully formed CGBitmapContext, and the method returns a UIImage generated from that context. Almost like a UIView/CALayer.



So now your thinking, "Yeah, thats cool, but why the [INSERT FOUR LETTER WORD] would i want to use it ?" Well young grasshopper, have you ever wanted to mask a image in code? You know to do those trendy rounded corners ... well yes you can use CALayer's however the idea of using those off the main thread makes me uneasy, and we all know the cool kids do things in the background.


The above actually creates a rounded rect on the fly, and masks the image with it. It's made to be used in a category on UIImage. But look closer, yep thats right kids, no boiler plate, ZERO, NADA, 另, SQUAT (i think you get the point)!

I should take a moment to mention that the awesome code for the rounded rect comes from the awesome Oliver Drobnik, i have the utmost respect for this guy, not just for this snippet, but if you've ever seen his Rich text label and it's associated projects, you'll understand why real soon.

I took a picture [Silicon Valley Edition]

Palo Alto, CA 2011

I took a picture [HOLLYWOOD edition]

Hollywood Sign 2011

I took a picture [中文 edition]

扬手,中国 （Yangshou, China) 2009 

I took a picture [Apollo 11 Edition]

Buzz Aldrin @ WWDC 2011

I took a picture [Israel Edition]

Jerusalem's Old City  2010 Crappy Kodak, with a awesome zoom

Waipo Valley Hike

While some people think i spend all my time on a perpetual vacation, it is sadly not the case. Everyday there is a little bit of something or another to be done.

However since i've been on the Big Island i've made an effort to try and relax, and actually have a vacation. Its not like i'll be having another one anytime soon. Being an iPhone developer and having loads of time off aren't compatible ideals.

So yesterday i started creaming myself on the prospect of visiting Waipo Valley, however it seemed so distance, and far from anywhere that it may as well have been on another planet. Initially i dismissed it, and decided instead to head for Akaka falls, a lovely 400ft waterfall only 20 minutes bus ride away.

However when my bus got to Akaka falls i didn't get off. It was a beautiful day, my camera was charged and my memory card was empty. I rode all the way to Waimea, in the north of the island, glimpsing the Towering Mount Kea, on the left and the steep coast to my right.

Though my consumption and research using the fantastic Offmaps i had learnt about a trail, just to the north of Waimea, that appeared to reach the valley. There is a more direct trek, that takes you to the head of the valley, however this is several Kilometers outside of town (READ not near the bus stop). So i decided to go a slightly different way, that allowed to me to go through town.

After walking though a residential neighbourhood to the north of the town. I found the entrance to the trail (above). Like all good hikers, i just ignored it and marched on.

After climbing the first hill, i got to what looked like a water treatment plant. Despite the signs at the gate, i vehicle from the Hawaii water department drove past me, but said or did nothing.

After the passing the water treatment facility i got to yet another gate, informing me that i was doing something or another wrong ... i ignored it and continued the march. With this particular gate i had to choices, jump it, or use the huge hole in the fence. It's always great to have options.

I was greeted by field full of cattle. I have to say that walking though a field of cattle by yourself is one of the strangest experiences i've ever had. They all just stare at you, and track your every movement silently. It reminded me a lot of when i was in China.

Climbing the hill further revealed a 50 million gallon reservoir, that was bone dry. I assume it fills up with rainwater run off over the winter, and then drains in the summer. This was one of three big reservoirs buried in the hills.

After another 5-10 minutes of walking a finally reached the Kohala Forest Reserve, at this point i knew it was on. I opened that gate and marched onward.

It went from grassy cattle pasture, to rainforest in the blink of an eye. The trail was easy to follow, but due to my naivety i was wearing trainers...

Trainers that got completely murked. There is a water pipe that runs along the trail, in several places it is leaking, which caused the mud trail to flood. Initially just walking on the grass was enough, but there were several places where this simply wasn't enough.

The landscape changed quite rapidly, going from rainforest to hilly plateau in a matter of minutes. While your at least 3 miles away from the nearest human being, you amazingly have 3 bars of AT & T service. I had turned data off to save battery. I'm not the worlds most amazing hiker so i didn't really want to be stranded in the middle of nowhere with half a sandwich, and Nutri-grain bar.

By this time i was almost 2 hours into the hike, I wasn't physically tired but the trail isn't scenic. There isn't much to see, and certainly no one to talk to. While i knew roughly how much further i had to go, the fact that i knew i had to retrace all my steps was beginning to depress the hell out of me. Especially as i was starting to consider if this dotted line that i had sacrificed my time to was actually a route to nowhere. I spotted a small hill up ahead, and made a deal with myself. If the canyon wasn't over the hill, then it was time to call it a day.

And there it was, 2000ft straight down, almost 4 miles in the middle of nowhere. I was at photographic "pay dirt". After about 10 minutes of this beautiful vista, i high tailed it out of there, rain clouds where all around, and this is the last place you want to be when it rains, especially considering that i wanted to salvage what was left of my trainers.

Overall i learnt a couple of things about my hike.

• Never give up
• Carry more food & water
• Get hiking boots
• Hawaii (Especially the Big Island) is beautiful.

Hawaii: Oahu & Hawai'i (aka The Big Island)

To be completely honest i knew very little about Hawaii as whole before i came here. But i've learnt a lot in the last 5 days. Mainly that i need to learn to drive. So thats definitely on the list for when i get home (finally).

View Larger Map

Having flown into Oahu, i spent most of my time in Waikiki, Honolulu. As i was warned it was chock full of Japanese tourists showing off their Canon's and Nikons. I have nothing against my friends from the land of the Rising Sun, however i do suffer from a serious case of Lens envy.

After 6 days in the Japanese version of the Costa Del Sol, i've  flown to Hilo, on the big island, aka Hawai'i. Today, i felt like an idiot for even spending more than two days in Oahu.

Firstly the big island, is well, BIG. The road that runs around the entire coast is almost 300 miles long. I spent today in the car with some good people from Holland, we barely explored a quarter of the island. This place is huge.

What really stuck me is the differences in the flora in various parts of the island. In some places it looks like a Rain forrest, while in others it looks like the surface of Mars. The above is the beautiful rainbow falls.

This is an example of the rainforest like terrain. It even has a canopy that the Brazil Rainforest would be jealous of. Really makes me look forward to the day i finally set foot on the continent of South America, Un dia, un dia.

Then there is the black volcanic rocks. While i know the landscape was formed by magma, it almost seems as if it's been scared by it. I've been fortunate enough to see some amazing things. But this is truly fascinating.

Auto incrementing version numbers in Xcode

Over the last month or so i've had to kick out a lot of betas for a project. Seeing as i use the fantastic Test Flight. I have to change the version number before i upload each build otherwise Test Flight will overwrite an existing build which is the last thing that we want.

I don't think anyone actually enjoys editing a plists, whether its in Xcode plist editor or the down and dirty XML. So has a result it was the perfect opportunity to get familiar with xcode's build process, and how to tie external scripts into it.

I use 3 segment version numbers (1.1.1), where the first digit is the major version, second digit is the minor version, and the 3rd digit is the build. For the benefit of the team, i wanted to have the latest commit hash in the build number so that people could quickly reference it and know whats going on.

With some direction from this post by Duane Sibilly i was able to hack together the below.

I Took a Picture [Hong Kong Edition]

Hong Kong 2009 - Taken on crappy 8Mpx Kodak with no Tripod ;)

i Took Picture [LA Edition]

Walt Disney Concert Hall LA

Goodnight San Francisco

The Mighty Pacific

When i'm not winning iOS Dev Camp, answering emails or writing code i like to take photos. Lots and lots of photos. As my time in the Bay Area comes to an end, i thought that it might be nice if i actually took the time to visit the Pacific Ocean.

Initially it was foggy (like it usually is) however it soon cleared up.

The birds came out...

As did the people ...

The sun shone ...

And everything was well with the universe (if only for today)

I Took a Picture [SF Edition]

HDR of San Francisco with 3 RAW 14Mpx Exposures processed in Photomatix Pro (Unlicensed ^_^ )

This is what 16k miles looks like

Thanks to the great folks at the great circle mapper, i now know what a 16k mile journey looks like.

The Golden Gate

After years of just seeing it in photos i got the opportunity to photograph it myself. It was the culmination of a fantastic day; the end of WWDC and an excellent talk by Buzz Aldrin.

Many people have asked during my journey if i keep a journal. While i don't in a conventional sense, photo's like these will help me remember this experience for a lifetime. 

What isn't always obvious is that the Golden Gate is essentially in the middle of nowhere. There is no easy way to get there from downtown San Francisco without a car, so i had to get my bike on, by chance i was able to rent one at a bike shop near 4th & Harrison. The $400 deposit scared the crap out of me at first, but it was alright in the end.

San Francisco is hilly place, so my plan was to cycle along the Embarcadero, which runs parallel to the shoreline (read: nice and flat). The previous link goes to my little weekend project. I built an app called gpxshare which allows people to upload and share GPX tracks for free. 

This was some what of a rambling post, but i just wanted to share some of these awesome pictures.

Core Data & Multi-Threading, part 1337

So i've made yet another Core Data Discovery, at this rate i might need to write a ebook. Now we all know that the golden rule of using Core Data with different threads is to not share contexts between threads.
So if you need to refer to an object on multiple threads you need to use it's NSManagedObjectID. Thats all well and good, but what if you need to call [NSManagedObjectContext save:] multiple times. Well in short it's gonna suck. Well thats cool you say, i can just use the id anyway ... Not quite. There are two types of ID's, permanent and temporary.
Now in my experience Core Data seems to get confused when you use temporary ID's to look up objects on another NSManagedObjectContext. So really to stop these conflicts we need to get a permanent id, but we need to obtain one of these ID's without saving the NSManagedObjectContext.


Well are you ready for the magic ... Shazam

[NSManagedObjectContext obtainPermanentIDsForObjects: error:]

This awesome method will take an array of managed objects, and give them permanent ID's. From my brief tests the overhead is minimal compared to the traditional save method.

Thats all i've got for today, keep on trucking.

[]'s 4 life

Asynchronous Core Data searches with Blocks

I was recently fortunate enough to be able to drop iOS 3 support on a project. This meant that i could start to play around fully with Blocks on iOS. One thing that has always got on my nerves is that there is no built in support for asynchronous Core Data searches.

Previously i tried to wrap up potentially long operations in a special FRCoreDataOperation a subclass of NSOperation. However this was a pain, as i would then have to subclass it or modify the parent class to provide me with a simple callback when the task was complete.

What i really longed for was the way in which you make Ajax requests in jQuery, that of course requires closures, which are of course provided in the form of Blocks. So after hacking around for a bit i came up with this.

Now this is my first real time using blocks outside of simple things like iteration etc. It means that i can do

Now here's the part where i pat myself on the back. The callbacks are executed on the main thread, after the async fetch request is completed. Plus it gets better, The NSArray, for the onComplete block contains a list of the returned objects that are registered with the NSManagedObjectContext for the main thread, or in other words the NSManagedObjectContext you used to perform the fetch.

Once i touch down in the valley i plan to extend this to manage saves as well, making the basic CRUD operations with Core Data "scroll like butter".