I'm creating a modular open-source library. Let's say the project has 15 .m files in it.
Should I (1) release it like the Venmo iOS SDK (Cocoa Touch Static Library) or (2) release it like JSONKit (just the source code)?
Releasing as source code means you, and your developers, don't have problems when a new architecture comes out. A static library built as armv6 wouldn't work with the latest Xcode today.
One caveat with source code releases, since you don't know what build settings the project it's added to will have, you'll need to do extra work to make sure it builds without warnings as best you can, even for pedantic warnings.
I prefer frameworks over static libs. Its easier to ship resources in the framework bundle if you eventually need to and there no cost to dynamic linking. If its pure C and the libraries dependencies are guaranteed to be there then it might be ok. But in general I try to avoid static linking unless I know the target OS has the exact dependencies for that binary at deployment time.
Its much easier to load a dynamic library with the endpoints you need at runtime (which were compiled for that exact platform but have the same external interface) than it is to fail with a static lib that was compiled directly to external dependencies which dont exist on the target platform.
Maybe Im crazy but this is what Ive always done in C, C++ or obj C. Just my opinion.
http://en.wikipedia.org/wiki/Static_library
We have a codebase for a sync library written in Objective-C. In general it's only using stuff from the Foundation framework (NSArray's, NSDictionary's, NSURLConnection's etc.).
We also use some Cocoa-specific functionality in this codebase: KVO and delegation.
Is it possible to compile this codebase to other platforms, similar to how it's possible to compile C/C++ code to multiple platforms? How should I go about doing this? What tools would I need?
edit: The platforms we're mostly interested in (if possible of course): Windows, Android, BlackBerry, Windows Phone 7
Thanks in advance.
Here is a delightful article from cocoawithlove - Options for porting Objective-C/Cocoa apps to Windows. It atleast answers how to port ObjectiveC to windows.
I'm writing a command line tool in Objective-C (within xCode) that uses the Foundation Framework. I have to use Objective-C because I need to unarchive objects previously archived by NSKeyedArchiver.
My question is, I'm wondering if I can now use this compiled application on my Linux web server.
I'm not sure if there would be a runtime issue or if the executable could be its own standalone program that could actually run on my Linux server.
I'd appreciate any feedback.
You can use The Cocotron to build your app targeted to Linux. It is an actual Cocoa implementation meant to fully interoperate (although it's not 100% complete of course), as opposed to GNUstep which is not meant to work that way. I use this and it is awesome.
No, you cannot run a program that was compiled on and for a Mac on a Linux system. So you will have to compile it for (and on) Linux. Apple's Foundation framework is not available for Linux, but have a look at GNUstep, a free and open Cocoa implementation.
I don't know if GNUstep can read archives that have been archived with Cocoa's NSKeyedArchiver, though.
I have provided a wrap-up on how to compile a command line tool based on the Cocotron Foundation framework on my blog.
This does also include a step by step guide on how to cross compile the Foundation framework for Ubuntu Linux.
Hope this is helpful!
Has anyone used Google's Protocol Buffers when developing applications in Objective-C?
Are there any current projects for compiling .proto files into Objective-C, all the Google docs simply refer to Java, C++ or Python.
I've been working on an fork of Cyrus' project. It's based on protobuf 2.3 and works as a protoc plugin (protoc-gen-objc) instead of requiring a modified protobuf distribution.
You can find it as the protobuf-obj project on GitHub.
The Third Party page lists this Objective-C port. Unfortunately the project appears to be empty at the moment, but it's encouraging to see it anyway. I had heard internal rumours of the project, but hadn't seen it as an open source project before today.
You could get in touch with the project owner (Cyrus Najmabadi) to ask about it though...
(Small piece of trivia - Cyrus used to work on the C# team in Microsoft before he joined Google.)
This may or may not be helpful, but Apache Thrift (originally developed at Facebook) supports Cocoa, and seems to have people attempting to use it in the iPhone.
Thrift officially supports more languages. But Protocol Buffers have 5x the Stack Overflow interest, so who knows if it's a good replacement in terms of maintenance—not to mention compatibility with your own project! Still, maybe it's worth consideration.
I just asked a related question you may find helpful if it gets good answers: Any success using Apache Thrift on iPhone?
Protocol Buffers v3 supports Objective-C
Protocol Buffers v3 supports Objective-C as a first class language.
To generate Objective-C code from a .proto file call the compiler with the objc_out option:
protoc --proto_path=src --objc_out=build/gen src/foo.proto src/bar/baz.proto
I prefer to use c++ generated classes within my objc projects, works just fine.
I did try the objc PB version but without success.
What would be the best way to write Objective-C on the Windows platform?
Cygwin and gcc? Is there a way I can somehow integrate this into Visual Studio?
Along those lines - are there any suggestions as to how to link in and use the Windows SDK for something like this. Its a different beast but I know I can write assembly and link in the Windows DLLs giving me accessibility to those calls but I don't know how to do this without googling and getting piecemeal directions.
Is anyone aware of a good online or book resource to do or explain these kinds of things?
Expanding on the two previous answers, if you just want Objective-C but not any of the Cocoa frameworks, then gcc will work on any platform. You can use it through Cygwin or get MinGW. However, if you want the Cocoa frameworks, or at least a reasonable subset of them, then GNUStep and Cocotron are your best bets.
Cocotron implements a lot of stuff that GNUStep does not, such as CoreGraphics and CoreData, though I can't vouch for how complete their implementation is on a specific framework. Their aim is to keep Cocotron up to date with the latest version of OS X so that any viable OS X program can run on Windows. Because GNUStep typically uses the latest version of gcc, they also add in support for Objective-C++ and a lot of the Objective-C 2.0 features.
I haven't tested those features with GNUStep, but if you use a sufficiently new version of gcc, you might be able to use them. I was not able to use Objective-C++ with GNUStep a few years ago. However, GNUStep does compile from just about any platform. Cocotron is a very mac-centric project. Although it is probably possible to compile it on other platforms, it comes XCode project files, not makefiles, so you can only compile its frameworks out of the box on OS X. It also comes with instructions on compiling Windows apps on XCode, but not any other platform. Basically, it's probably possible to set up a Windows development environment for Cocotron, but it's not as easy as setting one up for GNUStep, and you'll be on your own, so GNUStep is definitely the way to go if you're developing on Windows as opposed to just for Windows.
For what it's worth, Cocotron is licensed under the MIT license, and GNUStep is licensed under the LGPL.
You can use Objective C inside the Windows environment. If you follow these steps, it should be working just fine:
Visit the GNUstep website and download GNUstep MSYS Subsystem (MSYS for GNUstep), GNUstep Core (Libraries for GNUstep), and GNUstep Devel
After downloading these files, install in that order, or you will have problems with configuration
Navigate to C:\GNUstep\GNUstep\System\Library\Headers\Foundation1 and ensure that Foundation.h exists
Open up a command prompt and run gcc -v to check that GNUstep MSYS is correctly installed (if you get a file not found error, ensure that the bin folder of GNUstep MSYS is in your PATH)
Use this simple "Hello World" program to test GNUstep's functionality:
#include <Foundation/Foundation.h>
int main(void)
{
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
NSLog(#"Hello World!.");
[pool drain];
return;
}
Go back to the command prompt and cd to where you saved the "Hello World" program and then compile it:2
gcc -o helloworld.exe <HELLOWORLD>.m -I /GNUstep/GNUstep/System/Library/Headers -L /GNUstep/GNUstep/System/Library/Libraries -std=c99 -lobjc -lgnustep-base -fconstant-string-class=NSConstantString
Finally, from the command prompt, type helloworld to run it
All the best, and have fun with Objective-C!
NOTES:
I used the default install path - adjust your command line accordingly
Ensure the folder path of yours is similar to mine, otherwise you will get an error
Also:
The Cocotron is an open source project which aims to implement a cross-platform Objective-C API similar to that described by Apple Inc.'s Cocoa documentation. This includes the AppKit, Foundation, Objective-C runtime and support APIs such as CoreGraphics and CoreFoundation.
http://www.cocotron.org/
WinObjC? Windows Bridge for iOS (previously known as ‘Project Islandwood’).
Windows Bridge for iOS (also referred to as WinObjC) is a Microsoft open source project that provides an Objective-C development environment for Visual Studio/Windows. In addition, WinObjC provides support for iOS API compatibility. While the final release will happen later this fall (allowing the bridge to take advantage of new tooling capabilities that will ship with the upcoming Visual Studio 2015 Update),
The bridge is available to the open-source community now in its current state. Between now and the fall. The iOS bridge as an open-source project under the MIT license. Given the ambition of the project, making it easy for iOS developers to build and run apps on Windows.
Salmaan Ahmed has an in-depth post on the Windows Bridge for iOS http://blogs.windows.com/buildingapps/2015/08/06/windows-bridge-for-ios-lets-open-this-up/ discussing the compiler, runtime, IDE integration, and what the bridge is and isn’t. Best of all, the source code for the iOS bridge is live on GitHub right now.
The iOS bridge supports both Windows 8.1 and Windows 10 apps built for x86 and x64 processor architectures, and soon we will add compiler optimizations and support for ARM, which adds mobile support.
I have mixed feelings about the Cocotron project. I'm glad they are releasing source code and sharing but I don't feel that they are doing things the easiest way.
Examples.
Apple has released the source code to the objective-c runtime, which includes properties and garbage collection. The Cocotron project however has their own implementation of the objective-c runtime. Why bother to duplicate the effort? There is even a Visual Studio Project file that can be used to build an objc.dll file. Or if you're really lazy, you can just copy the DLL file from an installation of Safari on Windows.
They also did not bother to leverage CoreFoundation, which is also open sourced by Apple. I posted a question about this but did not receive an answer.
I think the current best solution is to take source code from multiple sources (Apple, CocoTron, GnuStep) and merge it together to what you need. You'll have to read a lot of source but it will be worth the end result.
I'm aware this is a very old post, but I have found a solution which has only become available more recently AND enables nearly all Objective-C 2.0 features on the Windows platform.
With the advent of gcc 4.6, support for Objective-C 2.0 language features (blocks, dot syntax, synthesised properties, etc) was added to the Objective-C compiler (see the release notes for full details). Their runtime has also been updated to work almost identically to Apple's own Objective-C 2.0 runtime. In short this means that (almost) any program that will legitimately compile with Clang on a Mac will also compile with gcc 4.6 without modification.
As a side-note, one feature that is not available is dictionary/array/etc literals as they are all hard-coded into Clang to use Apple's NSDictionary, NSArray, NSNumber, etc classes.
However, if you are happy to live without Apple's extensive frameworks, you can.
As noted in other answers, GNUStep and the Cocotron provide modified versions of Apple's class libraries, or you can write your own (my preferred option).
MinGW is one way to get GCC 4.6 on the Windows platform, and can be downloaded from The MinGW website. Make sure when you install it you include the installation of C, C++, Objective-C and Objective-C++. While optional, I would also suggest installing the MSYS environment.
Once installed, Objective-C 2.0 source can be compiled with:
gcc MyFile.m -lobjc -std=c99 -fobjc-exceptions -fconstant-string-class=clsname (etc, additional flags, see documentation)
MinGW also includes support for compiling native GUI Windows applications with the -mwindows flag. For example:
g++ -mwindows MyFile.cpp
I have not attempted it yet, but I imagine if you wrap your Objective-C classes in Objective-C++ at the highest possible layer, you should be able to successfully intertwine native Windows GUI C++ and Objective-C all in the one Windows Application.
Check out WinObjC:
https://github.com/Microsoft/WinObjC
It's an official, open-source project by Microsoft that integrates with Visual Studio + Windows.
If you just want to experiment, there's an Objective-C compiler for .NET (Windows) here: qckapp
You can get an objective c compiler that will work with Windows and play nice with Visual Studio 2008\2010 here.
open-c flite
Just download the latest source. You don't need to build all of CF-Lite there is a solution called objc.sln. You will need to fix a few of the include paths but then it will build just fine. There is even a test project included so you can see some objective-c .m files being compiled and working in visual studio. One sad thing is it only works with Win32 not x64. There is some assembly code that would need to be written for x64 for it to support that.
A recent attempt to port Objective C 2.0 to Windows is the Subjective project.
From the Readme:
Subjective is an attempt to bring Objective C 2.0 with ARC support to
Windows.
This project is a fork of objc4-532.2, the Objective C runtime that
ships with OS X 10.8.5. The port can be cross-compiled on OS X using
llvm-clang combined with the MinGW linker.
There are certain limitations many of which are a matter of extra
work, while others, such as exceptions and blocks, depend on more
serious work in 3rd party projects. The limitations are:
• 32-bit only - 64-bit is underway
• Static linking only - dynamic linking is underway
• No closures/blocks - until libdispatch supports them on Windows
• No exceptions - until clang supports them on Windows
• No old style GC - until someone cares...
• Internals: no vtables, no gdb support, just plain malloc, no
preoptimizations - some of these things will be available under the
64-bit build.
• Currently a patched clang compiler is required; the patch adds
-fobjc-runtime=subj flag
The project is available on Github, and there is also a thread on the Cocotron Group outlining some of the progress and issues encountered.
Get GNUStep here
Get MINGW here
Install MINGW
Install GNUStep
Then Test
If you are comfortable with Visual Studio environment,
Small project: jGRASP with gcc
Large project: Cocotron
I heard there are emulators, but I could find only Apple II Emulator http://virtualapple.org/. It looks like limited to games.
First of all, forget about GNUStep tools. Neither ProjectManager nor ProjectCenter can be called an IDE. With all due respect, it looks like guys from GNUStep project are stuck in the late 80-s (which is when NeXTSTEP first appeared).
Vim
ctags support Objective-C since r771 (be sure to pick the pre-release 5.9 version and add --langmap=ObjectiveC:.m.h to the command line, see here), so you'll have decent code completion/tag navigation.
Here's a short howto on adding Objective-C support to Vim tagbar plugin.
Emacs
The same applies to etags shipped with modern Emacsen, so you can start with Emacs Objective C Mode. YASnippet will provide useful templates:
and if you want something more intelligent than the basic tags-based code completion, take a look at this question.
Eclipse
CDT supports Makefile-based projects:
-- so technically you can build your Objective-C projects out of the box (on Windows, you'll need the Cygwin or MinGW toolchain). The only problem is the code editor which will report plenty of errors against what it thinks is a pure C code (on-the-fly code checking can be turned off, but still...). If you want proper syntax highlighting, you can add Eclim to your Eclipse and enjoy all the good features of both Eclipse and Vim (see above).
Another promising Eclipse plugin is Colorer, but it doesn't support Objective-C as of yet. Feel free to file a feature request though.
SlickEdit
SlickEdit, among other features of a great IDE, does support Objective-C. While it is fairly complex to learn (not as complex as Emacs though), I believe this is your best option provided you don't mind purchasing it (the price is quite affordable).
Additionally, it has an Eclipse plugin which can be used as an alternative to the stand-alone editor.
KDevelop
Rumor has it there exists a KDevelop patch (15 year old, but who cares?). I personally don't think KDevelop is feature-superior compared to Emacsen, so I wouldn't bother trying it.
The above also applies to Objective-C development on Linux, since all of the tools mentioned are more or less portable.
As of 2021, the GNUstep Windows MSVC Toolchain allows to integrate Objective-C code in any Windows app, including Visual Studio projects using LLVM/Clang. This includes support for Automatic Reference Counting (ARC) and Objective-C 2.0 features such as blocks.
The project includes the Foundation, CoreFoundation, and libdispatch libraries from GNUstep. It does currently not include any UI framework such as AppKit or UIKit, but it can be used to e.g. write a Windows-specific UI with cross-platform business logic written in Objective-C.