Are there any tutorials describing how to create a library or is it framework for the iPhone? I have a number of methods that are shared between applications. These will be better maintained as a library.
Put your code in a static library (as Roger indicated via his link). However, consider using an Xcode cross-project reference to "import" that static library into all the other projects that need it. I've whipped up a tutorial explaining how to do this (and why I think it's better than creating a "fat" Universal Binary): http://www.clintharris.net/2009/iphone-app-shared-libraries/
There is a lot of information on the web that can help with this for example this.
A much more recent (and more powerful) way to do the "single library file that covers both simulator and devices":
Build fat static library (device + simulator) using Xcode and SDK 4+
(I wrote one of the posts referred to in the accepted answer; that was valid for Xcode3 at the time, but Apple deliberately broke it with later versions, and offered no alternative. So, we ended up with the SO question / answer above)
Related
I have been looking for 2 days now, trying to find a way to get a single iOS framework-file for the ZXing QR reader. The only thing i can find, is a ZXingWidget project to include in my own project. But here, i have to add path's, dependencies etc. for it to work.
Isn't there a way to create one single .framework file that can easily be added to any new projects needing this feature?
I have found a kstenerud iOS framework template to create frameworks, but i can't make it work with the ZXing project.
No, there's no good solution for this for iOS.
Frameworks are generally (always?) dynamically-linked libraries and Apple doesn't allow DLLs on iOS. Note that there are now framework builds for OS X.
It may be possible to hack Xcode to produce a framework with a statically linked library, but that's going against Apple's patterns which means I suspect it will push Xcode into corner cases which fail in subtle and hard to debug ways and which have a high chance of breaking across Xcode versions.
This opinion comes in part from talking to Apple Xcode engineers at WWDC about cleaning up the ZXing project files. There are new project files now that follow all the best practices they recommended but on iOS they still require the same include path and library linkage project customization that the old project files require.
Over the last few months I've come across various chatter of external/private libraries not being allowed in iPhone apps.[Just to be clear, this is not something thats going to come, its something I was wrongly under the impression that already exists.]
I was looking at the WunderRadio source: http://www.wunderradio.com/code.html
and I noticed they have 3+ .a files in there project.
libcCommon.a liblibmms.a and libffmpegLib.a are the ones I'm looking at.
Have I been misinformed about the use of this kinda of libraries in iPhone projects? Will Apple accept and approve projects that are using them? If so what is it thats not allowed? Is it just use of Apples own private and undocumented libraries, but you are allowed to include your own?
Many Thanks,
-Code
Static libraries have always been allowed for iOS development and there is no sign that position is going to change at any point (why would it?). Dynamic libraries are not allowed and will result in the rejection of your app.
I think they'd be crazy to do that.
There are so many 3rd party libraries out there that it would pretty much kill the developer crowd they've got now. Imagine if you had to write every library over, from scratch? That's nuts...
Of course, I have no proof one way or another. I just think they'd be insane to try and do that.
.a files are called static libraries. When you build your code, they essentially get compiled in at build time. These are definitely allowed by Apple. In fact, XCode provides a template for a "Cocoa Touch Static Library" when creating a new project.
.dylib files on the other hand are dynamic libraries and are not allowed by Apple. They are separate code files that can be shared by multiple applications as their code gets brought in to your app at run time.
Saurik (the guy who created Cydia) solved this issue by creating Mobile Substrate for jailbroken iPhones. It allows devs to create dynamic libraries in order to alter the functionality of existing Apple classes.
Hope this clears the issue up.
This question comes from this other one I asked earlier: Calling custom Objective-C from a pyobjc application?
I want to re-use a small part of the app logic from my iPhone app in its server-side component, which runs on OSX. Based on what I was told in the other question, it looks like I need to compile a "framework" for both iOS and OSX from this little piece of app logic.
If we assume that I am able to isolate all the code that is to be in this framework into a single .h/.m pair of files that has no other non-Cocoa dependencies, what would be the easiest way in XCode to build this framework for each architecture and avoid double-coding all this logic on the server?
I tried adding a new OSX framework build target to my iPhone project, but this doesn't get very far and XCode bails out pretty quickly with:
target specifies product type 'com.apple.product-type.framework', but there's no such product type for the 'iphonesimulator' platform
Any help much appreciated, as I am currently dupe-implementing to keep things moving forward, but this is pretty obviously becoming a huge waste of time and source of errors when the implementations become slightly out-of-sync.
Depends on what you used in your custom class. If you did not use anything from UIKit / AppKit then the class is probably going to live well on either platform, otherwise, you’d have to use target conditionals and include separate code specially written for both platforms.
You can have multiple targets in one Xcode project, their Base SDK set separately for the Mac / iDevices.
Adam's comment to my original question answers this question. Although still interested to see if there is a way to do it all from a single XCode project, the solution I have now is plenty good enough for what I wanted to achieve.
Is it possible to create an own obj-C Cocoa Touch framework which can be used by other developers? And furthermore can you protect this framework?
I've created templates for Xcode 4 that allow you to build universal iOS frameworks (which work in both device and simulator).
Once the templates are installed, you simply select "Static iOS Framework" when creating a new project and it does the rest. It also works with unit tests.
https://github.com/kstenerud/iOS-Universal-Framework
You can create a static library. There is an option in the XCode project chooser to do this. You'll have to distribute the compiled static library file and the header files to users of your library. Your actual implementation files (.m) do not need to be distributed.
GHUnit does a good job of this - packaging up the libraries for both simulator and device - so I recommend looking at this project. (I also recommend using this library for unit testing :-)
The frameworks in Objective C are typically just C / ObjC code and a bunch of classes, nothing amazingly special. As such, you can create your own if you'd like, and then just include that in your project when you build it. The iPhone doesn't care about the difference, it just knows to put all that code into your app, along with everything else.
Have a look at the Framework Programming Guide on Apple's website. It will get you started. Essentially what you'll do is create a Framework project in XCode and then go from there.
As for "protecting" your framework, I assume you mean making your code unreadable. I'm not sure if and how you can do this, but perhaps Apple's guide will say something about it.
Yes you can create frameworks for use with Cocoa Touch.
However there are these caveats:
has to be a statically linked libary, no dynamic loading (dyld) for us
should be a combined (lipo) library for i386 (simulator), arm6 and arm7
you need to hack a bundle project into a framework
you should embed (small and few) images into the library so that the developer does not have to mess around with resources but just drags/drops it into his project
... or if you have large and many images build a bundle with these
I have guides for these things on my site.
1+2 = http://www.drobnik.com/touch/2010/04/universal-static-libraries/
The other links you have to google because this site does not let me post more than one URL.
You could make a static library available as binary (i.e. rudimentary "protection") to third parties, but not a dynamic one, as Apple's App Store policy prevents dynamic linking.
Take a look at a worked example for static libraries given at
this site
If you're going to do it, in my opinion JSON.framework is a great example to follow. To hide/obfuscate the source code is a different story, and a different question entirely,
When creating a new project, navigate to iOS > Framework & Library > Cocoa Touch Framework, it's as simple as that. When you are successfully compile, .framework will be created under Products folder in XCode. Right click to show in Finder, and you can find the output.
It's unlikely this will work the way you want it to because the other developers won't be able to use your framework. This StackOverflow Question explains why.
The error I'm getting:
in /Users/robert/Documents/funWithFrameworks/build/Debug-iphonesimulator/funWithFrameworks.framework/funWithFrameworks, can't link with a main executable
Cliff notes:
trying to include framework
doesn't want to link
More detail:
I'm developing for a mobile device... hint, hint using Xcode and I'm trying to make my
own custom framework which I can include from another application. So far, I've done the following:
Create a new project; an iPhone OS window based app.
Go to target info-> under packaging, change the wrapper extension from app to framework
Go to Action->new build phase -> copy headers. Change roles of headers to 'public'
From my application, I add the framework to the frameworks group.
Apple clearly said that you can not use dynamic libraries on their mobiles. And a private framework is just this.
You can, however, use static libraries.
Egil, that's usually considered as one of the implications of section 3.3.2 of the iPhone developer agreement, which (in part) forbids plug-in architectures or other frameworks. The fact that they don't provide an Xcode project template for an iPhone-compatible framework tends to reinforce the idea, though of course it could just be an oversight or something they're discouraging without actually forbidding.
Whether this is the intended meaning of that section is something you'd have to ask Apple about, and possibly consult a lawyer, but this is where the oft-stated "no frameworks" idea comes from.
For those who have framework code they'd like to use in an iPhone app, an alternative approach is to use the framework code to build a static library. That then gets compiled into the application instead of getting dynamically loaded at run time. The fact that it's part of the application executable avoids any potential concerns about this part of the agreement.
Though dynamic libraries are not allowed, you CAN create a framework (using static libraries and lipo).
Check out: http://accu.org/index.php/journals/1594
I haven't tried it for so called mobile device, but I would guess its very similar to the method for a regular Cocoa application. Check out this tutorial:
Embedded Cocoa Frameworks