Python to Objective C (Expected Learning Curve) - iphone

I'm a self-taught programmer who jumped into Python as my first language about 7-8 months ago. I'm fairly solid at making things work, though my foundational knowledge is limited thanks to my questionable choice in college to not study computer science.
Beyond Python, I'm not really familiar with C or other lower level languages.
I would like to teach myself Objective C as a foray into programming iPhone apps (as a hobby initially). I initially want to create relatively simple utility apps (I think they are relatively simple, at least).
Could any one give me a guess as to how long it might take me to pick up Objective C and actually produce a semi-decent app? If time is of the essence, should I just scrap it and go with HTML5?
I pick things up fairly fast but, again, my background in Comp Sci is really limited.
Sorry if this question is a bit too general and thanks for any insight!

You may take some time once you do not have experience with C. The "C way" is very important to understand Objective-C. You can learn Objective-C without C as well but you will find a lot of C pitfalls in your way.
Said that, I started a project in Objective-C some time ago after giving up Python with Cocoa. I find Objective-C pretty easy to learn - in one month I had made most of my application. I bet you will take a bit more of time because you are not used to C but it is not impossible to learn Objective-C in a relatively short time - let us say, two or three months.
If you have a very restrictive time, you may try HTML5, however. HTML5 uses JavaScript, whose semantics is closer to Python. At least you'll not get segmentation faults with HTML5 :) Also, JavaScript syntax is closer to C so it can be of a little help to learn Objective-C.
Anyway, I have found this great book, Become an XCoder, which seems to be focused on non-C programmers learning Objective-C. You can start by it.

I really can't tell you how long it will take you to produce a decent app, but I can definitely recommend Stanford's iOS Development class on iTunes U for learning Objective-C. Once you finished all lessons, you are pretty good to go for your first app. It is really good.

You should learn both, Objective-C and HTML5. HTML5 isn't very difficult to grasp even if you don't have any experience.

I had to learn objective-C a couple of months ago to make an app for an internship. I had experience with C/C++, and learning Obj-C wasn't difficult at all. What was difficult was learning to use the SDK. Granted, I had next to no experience with using something like it before, but it was a significant learning curve to get a handle on actually putting the app together using Apple's tools. If you're in the same boat, that's something that will probably add to the time it takes to produce a finished app. (I finished the app in about a month.)
I agree with other posters that there are some great Stanford tutorials on iTunes, but as a reference I found Kochan's Programming in Objective-C very valuable. He states in the intro that he does not expect prior C knowledge from readers, and doesn't think it's necessary -- might be a good book for your situation.
Depending on the complexity of the app you want to build, I think you could build something decent in a month or two.

Well when i started progamming for Objective-c i was well known in Java, but nothing close to C/Objective-c. It took me around 1 month to learn the basics (using tutorials etc).
There are some really good tutorials on iTunes (search for Objective-c seminar). I also used a couple of pdf's to use them as backup while making my first app. That helped alot!

Related

Has anyone had much success recently using the Cappuccino Framework?

I'm just creating my first project in Cappuccino without a lot of success. Looking for examples and documentation, there isn't a lot out there...
The differences from real Objective-C and the lack of libraries mean you cannot easily convert code directly from say a OS X desktop app. to Cappuccino.
As an experienced PHP, and RoR developer (besides the Java, VB, VC.....) I can't quite see the logic of abstracting/wrapping JavaScript in another language.
Any comments or suggestions for a more efficient framework?
If you have specific questions that can't be answered in the IRC channel (it just depends who's in there) you should post the question to the mailing list and someone will help you.
As for why you would want objective-j I'll point you to this blog post which contains several reasons why objj exists. http://cappuccino.org/discuss/2008/12/08/on-leaky-abstractions-and-objective-j/
I have converted several Objective-C classes nearly line for line into Cappuccino. Mostly it's a matter of changing NS to CP and changing pointers to non-pointers. What differences between Objective-C are you thinking about?
Indeed you could even take your existing XIB files from your Cocoa desktop app and convert them to Cappuccino using nib2cib. Here's how to work with Interface Builder using XCode 4: http://groups.google.com/group/objectivej/browse_thread/thread/786331dbcbc9c7b1.
I also recently started a project in Cappuccino and what I could say is: definitely it worth it. I'm used with javascript as well as (but less) cocoa (which helps). In short, the javascript is very fine, probably one of my favorite language because of it's flexibility. But it does lack of structure. For example there is no class in javascript and you have to trick with object inheritances, prototyping and so on. By using the Cappuccino framework at first you have all those very convenient facilities but also you do not reinvent the wheel each time. This is cross browser standardized so that you only have to focus on your code and not on the IE whims. As it is based on cocoa, cappuccino also comes with the MCV scheme in mind which again let you structure your project in an efficient way.
Ok you probably already know all this. What I could tell now about the learning curve is that I had to find the right tools to really get in. i.e.Installing cappuccino (sudo Starter/bootstrap.sh), creating a simple nib application (capp gen -t NibApplication YourApplication) then using xcodecapp-cocoa to listen, convert and open the project into Xcode what probably the hardest part of this learning curve to me…
Now if you are still not satisfied with cappuccino, I can only suggest to look at another framework like http://javascriptmvc.com/ , www.grooveshark.com used it to do their amazing webapp-site but I personally would never go back to html for building a web application. (conversely I would not use cappuccino for a webpage neither, "The cobbler should stick to his last")
I began writing cappuccino a couple of months ago and had a lot of difficulty when it came to setting up the proper development environment. I also had numerous problems writing working client server code that worked well.
I eventually broke through and started doing better with Cappuccino and then I found these video tutorials that would have helped so much earlier on. They did cost me $30 but I really wished I had watched these at the start because they help you get set up properly as a developer and get you started on the right learning curve.
I actually discovered these videos when using Cappuccinos IRC which has helped me a couple of times when I couldn't find an answer.
Info on the videos here: http://cappuccino.org/discuss/2011/10/19/cappuccino-training-course-ideveloper-tv/

Are these really the steps I need to take to finally program for iPhone?

First I went and purchased:
Beginning iPhone Development: Exploring the iPhone SDK
And it said I should know Objective-C
Then I went and purchased Learn Objective–C on the Mac by Mark Dalrymple, Scott Knaster
And it said I should know C
then now I'm at the beginning with Learn C on the Mac by Dave Mark
So this is the long journey I need to take to finally start producing actually GOOD apps for the iPhone
C > OBJECTIVE-C > APPS?
Nah, forget learning C, just go straight to Objective-C. My humble opinion.
If the Learn Objective C book assumes you know C then is it likely to not go into the code in as much detail as you need, making it more difficult for you. However you don't need to learn all of C, or even a lot, so working through a book will take some time.
Better, as silky says, jump straight into Objective-C, and when you struggle just come to SO
If you're a complete beginning to computer programming, I might get some information about programming in general before going to Objective-C; it's an easy language, but it would help to general programming constructs (like if statements, etc) and how they work before you learn how Objective-C does it.
I would think that you WOULD want to learn C first. Most objective-c books are going to presume that you know the difference between pointers and values, that you know basic looping and control statements, and that you understand arrays, structs, and functions.
Contrary to some other advice, unless an objective-c book you buy specifically starts from zero and makes that claim, I WOULDN'T just jump in. People will say that objective-c is easy, but that's not necessarily true, since with compiled languages (unlike interpreted ones where speed doesn't matter so the runtime can hide complexity via abstraction) the devil is in the details.
If you read an objective C book and you don't know what the "*" is for in front of a variable, start with C. My two cents.

Frameworks & Doneworks: Do you thinks it is cool to use those?

By using somebody else's works you advertize the authors of those works (At least, among other programmers). Do you think it is cool?
This line of questioning could go up one more level and become "Programming Languages: Do you think it's cool to use those?" Because someone(s) wrote those too. I can continue this up to the types of computers, to the components, etc...
Monet did not make the brushes or the paint or the canvas (well maybe, not sure). But who creates those building blocks is not quite what stands out at the end.
Languages/Frameworks/etc were built and released to be utilized by the masses (or make money for the creators).
I think it's always cool. Be more efficient, reduce redundancy, promote other useful code.
If you're trying to learn though, reading and understanding the framework you're using is very helpful. There are always other things you can be programming and learning, not necessarily reinventing the wheel.
If using their work has saved you time reimplementing the same thing (but with more bugs) then don't they deserve credit?
Or put another way, stealing other peoples' work without credit (or paying them, depending on whether we're talking about free or commercial software here) isn't cool.
Of course, nobody's stopping you from writing your own framework, if that's what you want to do...
It depends on what kind of programming you're doing.
Are you doing it to achieve a finished program? Then a framework could save you a lot of time.
Are you doing it to create something truly original? Then a framework might simply tie you into an existing way of thinking.
Rembrandt made his own paints. Michelangelo selected his own marble from the quarry. Alan Kay said "People who are really serious about software should make their own hardware". The Excel team famously has their own compiler. The iPhone ain't just an alternate firmware for the Blackberry. ISTM if you want to be at the very top of your game, you've got to get down and dirty with the nitty gritty of it.
I don't know anything about advertising, other programmers, or what's "cool", so I can't respond to those parts of your question.

What inherited code has impressed or inspired you?

I've heard a ton of complaining over the years about inherited projects that us developers have to work with. The WTF site has tons of examples of code that make me actually mutter under my breath "WTF?"
But have any of you actually been presented with code that made you go, "Holy crap this was well thought out!" or "Wow, I never thought of that!"
What inherited code have you had to work with that made you smile and why?
Long ago, I was responsible for the Turbo C/C++ run-time library. Tanj Bennett wrote the original 80x87 floating point emulator in 16-bit assembler. I hadn't looked closely at Tanj's code since it worked well and didn't require attention. But we were making the move to 32-bits and the task fell to me to stretch the emulator.
If programming could ever be said to have something in common with art this was it.
Tanj's core math functions managed to keep an 80-bit floating point temporary result in five 16-bit registers without having to save and restore them from memory. X86 assembly programmers will understand just what an accomplishment this was. Register space was scarce and keeping five registers as your temp while simultaneously doing complex math was a beautiful site to behold.
If it was only a matter of clever coding that would have been enough to qualify it as art but it was more than that. Tanj had carefully picked the underlying math algorithms that would be most suitable for keeping the temp in registers. The result was a blazing-fast floating point emulator which was an important selling point for many of our customers.
By the time the 386 came along most people who cared about floating-point performance weren't using an emulator but we had to support Intel's 386SX so the emulator needed an overhaul. I rewrote the instruction-decode logic and exception handling but left the core math functions completely untouched.
In my first job, I was amazed to discover a "safe ID" class in the codebase (c++), which was wrapping numerical IDs in a class templated with an empty tag class, that ensured that the compiler would complain if you tried for example to compare or assign a UserId into an OrderId.
Not only did I made sure that I had an equivalent Id class in all subsequent codebases I would be using, but it actually opened my eyes on what the compiler could do to guarantee correctness and help writing stronger code.
The code that impresses me the most, and which I try to emulate - is code that seems too simple and easy to understand.
It is damn difficult to write that kind of code. :-)
I have a funny story to tell here.
I was working on this Javaish application, filled with getters & setters that did nothing but get or set and interfaces and everything ever invented to make code unreadable. One day I stumbled upon some code which seemed very well crafted -- it was basically an algorithm implementation that looked very elegant = few lines of readable code, even though it respected every possible rule the project had to adhere to (it was checkstyled automatically).
I couldn't figure out who on the team could have written such code. I was dying to discuss with him and share thoughts. Thankfully, we had switched to subversion (from cvs) a few months earlier and I quickly ran am 'svn blame'. I loled all over the place, seeing my name next to the implementation.
I had heard stories about people not remembering code they wrote 6 months back, code that is a nightmare to maintain. I could not believe such a thing could happen: how can you forget code you wrote? Well, now I'm convinced it can happen. Thankfully the code was alright and easy to extend, so I've only experienced half of the story.
Some VB6 code by another programmer at my company I came across that handled the error conditions very well (whether it be deal with them directly or log them).
Along with some rather complex code that was well commented.
I know this will bring a lot of answers like,
"I've never find good code before I step in" and variations.
I think the real problem there is not that there isn't good coders or excellent projects out there, is that there's an excess of NIH syndrome and the fact that no body likes code from others. The latter is just because you have to make an intellectual effort to understand it, a much bigger effort than you need to understand you own code so that you dislike it (it's making you think and work after all).
Personally I can remember (as everyone I guess) some cases of really bad code but also I remember some pretty well documented, elegant code.
Currently, the project that most impressed me was a very potent, Dynamic Workflow Engine, not only by the simplicity but also for the way it is coded. I can remember some very clever snippets here and there, as well as a beautiful metaprogramming library based on a full IDL developed by some friends of mine (Aspl.es)
I inherited a large bunch of code that was SO well written I actually spent the $40 online to find the guy, I went to his house and thanked him.
I think Rocky Lhotka should get the credit, but I had to touch a CSLA.NET application recently {in my private practice on the side} and I was very impressed with the orderliness of the code. The app worked extremely well, but the client needed a few extensions. The original author had died tragically, and the new guy was unsophisticated. He didn't understand CSLA.NET's business object based approach, and he wanted to do it all over again in cut-and-dried VB.NET, without any fancy framework.
So I got the call. Looking at a working example of WinForm binding and CSLA.NET was pretty instructive about a lot of things.
Symbian OS - the old core bit of it anyway, the bit that dated back to the Psion days or those who even today keep that spirit alive.
And sitting right along side it and all over it is all the new crap created by the lowest bidders hired by the big phone corporations. It was startling, you could actually feel in your bones whether a bit of the code-base was old or new somehow.
I remember when I wrote my bachelor thesis on type inference, my Pascal-to-Pascal 'compiler' was an extension of a Parser my supervisor programmed (in Java). It had a pretty good structure as far as I can remember, and for me who had never done any serious Object-oriented programming, it was quite a revelation.
I've been doing a lot of Eclipse plug-in development and often had to debug into the actual Eclipse source code. While I haven't "inherited" it in the sense that I'm not continuing work on it, I've always been impressed with the design and quality of the early core.

Which technologies/concepts do you suggest I learn before creating an iPhone game?

Sorry if this is a broad question, but other than Objective-C, Cocoa, and OpenGL ES, what technologies or concepts would you suggest I read up on before writing a game for the iPhone? I'm a beginning game developer and need all the help I can get :)
MATHS - I would advise this topic
Some example areas of interest for applications in Game Development
Calculus, Geometry,The Cartesian Co-ordinate System, Vectors, Matrices, Transformations etc...
Sorry, my answer is not computing related.
A game tells a story, a great game tells a great story. So I would suggest to learn principles of storytelling.
Not going as scholar as Aristotle's Poetics, I recommend more modern Story by Robert McKee. It focuses on movie making, but I am pretty sure that many of the concepts he develops can be applied to game making.
You should read some articles on GameDev. Obviously, learning some of the fundamental concepts in computer graphics would be very helpful. But really, once you get to where you can write Objective-C and understand the APIs, go ahead and get started. You will learn a lot in the process; of course, keep learning and reading about these things I mentioned, but start coding. Find some books on game programming, particularly AI and so forth. Go ahead and get your feet wet programming though. Of course, be sure you learn your language thoroughly.
Quite frankly, I have found that I never know what I need to know until I actually get my hands dirty. That's why I suggested here that someone looking to jump into designing a 3-D iPhone game start with some simpler, targeted projects. These targeted projects can teach you core concepts as you put them to practical use. OpenGL seemed like this impossible-to-understand black box until I made myself perform some simple tasks with it. In a few weeks, I had an application based on it.
In college, I would spend weeks trying to understand the theory behind an aspect of thermodynamics, but then I would see one practical application for it and the whole thing would fall into place. Since then, I've focused on finding specific applications for concepts before spending too much time with the pure theory behind them.
A solid understanding of what makes a good gaming UI especially on the iPhone would be key, especially with the options it provides, be it accelerometers, or onscreen touch inputs.
I'd be sure to try out existing games and see what works, what doesn't, and what gets good feedback. You may also want to look at Flash and DS based games to see what works on other small screens/devices.