After I downloaded the latest Xcode with the 3.1.2 SDK, I can't build and test for 2.2.1 anymore. I have the 2.2.1 SDK in the proper directory of my Developer folder.
Is there a setting I have to change?
Yes, to choose an older SDK in the Active SDK popup you have to set either the Base SDK or the Deployment Target build setting of your target to a value equal to or less than 2.2.1.
The Base SDK expresses your intention of what API your code is written for.
The Deployment Target expresses your intention of the earliest iPhone OS you want your app to run on.
The Active SDK is your build-time choice of SDK to use, usually Device vs. Simulator. But you will fail if you try to build against an SDK that is older than what your code is written for. If you code is indeed written to compile against older SDKs and/or run on older OS versions, you must express this by setting the appropriate build settings in the Target. Otherwise the Active SDK popup will limit you to what it knows will work with your code.
Where are you trying to select it? As the base SDK?
You should always be linking against the newest SDK version (this is what an Apple engineer told me directly at an iphone dev event) and then set your Deployment Target back as far as you want. You should be able to set you iPhone OS Deployment Target back to the older SDK version.
This is because Xcode uses weak linking so it will leave out things from the newer SDK on older versions, you do need to do some conditional checking for specific API's/functions using things like respondsToSelector if you are using functionality that has changed across versions.
Related
I have written an app and its base SDK is set to 4.2, and at the moment it is in the app store with a deployment target set to 4.2, I'm sure you'll agree this is a bad idea because I am alienating all potential users who do not have the latest version of iOS installed.
So my question is, when deploying for an older version of iOS, how do I make sure it will run, i.e. how do I check whether I've used any modern API's that are not present in the deployment target iOS version?
The only sure-fire way to make sure your app will run is to test on a device running the older OS version you specify.
Even old versions of the iPhone Simulator (if you can find such) will not do a good job of checking for compatibility.
Most developers who want to support customers on iPhoneOS 3.x have access to an old test device, such as an used iPod Touch (hand-me-down, or purchased on eBay, etc.) running the OS version set in the app's Deployment Target. Otherwise, the developer is just guessing/gambling.
Check the documentation of the libraries or methods you are using. Test on the actually device installed with the version of the OS you wish to support.
Change the Base sdk version to 4.2, target sdk to 3.0 or any.
test the app in simulator as the target as simulator 3.0 r any.
But, when compared to 3.2 , 4.2 version has many new functionalities that do not work on 3.2 version devices.
So take respective steps to do for 3.2 r for 4.2.
The better idea is to find the version of the device , then give the accessibility based on the version.
Thanks,
Bharath
If I install SDK 4.0 of the iPhone OS will I still be able to create a non 4.0 iPad app?
I would ideally like to submit a iPad app in the next month but am also hoping to develop a 4.0 iPhone app is it possible to use the 4.0 SDK to create 3.0 iPad apps or am I going to need to computers?
You do not need two computers. You will have to install the two SDKs in two different directories. So far, it's always been the way that beta releases of the SDK were not meant (and not allowed) to generate apps for distribution.
But in the installer, just select another new directory and then install the second SDK there. That's all there is to it.
So far Apple has always provided a way to create Applications compatible to older versions of iPhone/iPad OS. The SDK installer will install the SDK in a version specific subdirectory. Additionally there is a "Current" directory hardlinking against the newest version. The old versions will still be available.
XCode will let you select an iPhone OS Version in the build settings and automatically figure out the correct SDK version/directory, so there's no need to fumble with paths or include directories.
Build against the latest SDK and set your "deployment target" to a lower version.
If you use new API calls (available in the SDK but not in the deployment version) check at runtime before calling them.
I'm a little confused about building an app for the app store and for the correct SDK & OS version. I have submitted my app to the app store, and in the app details screen of iTunes connection it says:
"Minimum OS Requirements : 3.1.2"
I haven't seen any apps on the app store that have 3.1.2 as the min OS, they all say 3.0. I read several things on here before I built it and I thought I understood everything!
Basically, my app doesn't use any code that only exists in > 3.0 so I would like the minimum OS to be 3.0. My build settings were:
Target Info
Base SDK: iPhone Device 3.0
iPhone OS Deployment Target: iPhone OS 3.0
Xcode Main Window
Active SDK: iPhone Device 3.1.2
I've heard about a minimum OS version being put in the Info.plist but I haven't got anything like that in mine.
I build the app exactly like that and submitted it. Are my app settings correct? Will my app display 3.0 in the app store or 3.1.2? I'm a little unsure as to why you set the Active SDK to the latest (3.1.2) when you want to target 3.0 , 3.1 & 3.12 devices, but it's what I read!
Any help advice be greatly appreciated!
Okay I've managed to figure it out after much reading!
Basically, the Active SDK is just a build time override of the Base SDK. By default, when the Base SDK changes it automatically changes the Deployment Target to the same OS as the SDK. So when I wanted to build the app under the 3.1.2 SDK but have it run on 3.0 OS, I changed the Active SDK to 3.1.2, but that had automatically changed the minimum OS (deployment target). I saw this by looking at the Info.plist file in the package contents in my .app file.
So the best thing to do is to set the Base SDK to the latest SDK (currently 3.1.2) and then manually set the Deployment Target to 3.0 OS. Once the 2 are different then it will no longer automatically change.
However, this means that your app can install on a 3.0 device that may have 3.0, 3.1, or 3.1.2 SDKs. Therefore, any frameworks, methods or properties you use that are only available in SDKs greater than 3.0 you will have to use conditionally.
When you get around to building the app, ensure that that Active Target is set as the same as your Base SDK, e.g. Device 3.1.2. But remember to compile your app under Device 3.0, Device 3.1, and Device 3.1.2 just to check for compiler warnings. This will ensure that you don't have any code accessing methods/frameworks that don't exist in any SDKs down to your Deployment Target.
I hope this helps anyone who is in my position and couldn't find a simple explanation of how it all works.
The SDK Compatibility Guide was very useful and informative. However it took just a little extra figuring out for me to be comfortable with the concept and how everything works. This image from the guide is useful:
(source: apple.com)
Go to the Project Info->Build and look at IPHONEOS_DEPLOYMENT_TARGET property
Actually I use 3.1.2 SDK and building an app that work nice on every OS higher than 2.2.1
After my upgrade to Snow Leopard and Xcode 3.2 (which I really regret a lot!!), Xcode lost all the SDK's. I'm one of those old-fashioned idiots who still want to develop for 2.2.1. But Apple does not offer me an old SDK download.
Now I was clever and made tons of time machine backups. But: What's the preferred way to get iPhone SDK 2.2.1 running with Xcode 3.2? Some guys said that's generally possible. I do hope so because I still don't believe in all those "faked" stats, and besided that, my app doesn't benefit from 3.x additional features so I would not want to constrain my market just for that lazyness.
Any idea?
Regardless of whether or not you're targeting iPhone OS 3.0 or not using any 3.0 specific features, you should always compile your app against the latest SDKs to benefit from bug fixes and performance improvements.
You can compile against the 3.0 SDK and set the iPhone OS Deployment Target to 2.2.1 and still cater for users who are using 2.2.1.
You may find that some methods have been deprecated, but that doesn't stop you from using them until you're ready to move on.
Get the 3.1 final sdk, it has the 2.2.1 sdk in it. On disk its usual location is:
/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS2.2.1.sdk
Also included is 3.0 and 3.1.
XCode 3.2 should have the prior iPhone SDKs available, just make sure you are setting your project's Base SDK setting to "iPhone OS 2.2.1". (Right-click on your top-level project icon in the Groups & Files browser in XCode and choose "Get Info", then go to the Build tab.)
Raffaello and others are correct: you can use the latest SDK and still target (and test on) older SDKs. For example, I'm using iOS4.0 (xcode 3.2.3) and testing on my iPhone 3g running 3.1.3.
To clarify the procedure:
- go to project info > build tab
- set Architectures:Base SDK (most likely) the latest
- set Deployment:iPhone OS Deployment Target to what ever you want (I have the option to go as far back as 2.0).
Hope this helps someone.
Like I said on other threads, the SDK and Deployment Target are different.
You can still use the latest SDK to build for an older OS.
Just go to your Target settings and under the Deployment section set the iPhone OS Deployment Target to whatever you'd like.
Cheers,
Raffaello Colasante
With the latest Xcode and SDK 3.0 beta when you create a new iPhone project, Xcode creates an SDK 3.0 project. If I want to revert to SDK 2.2.1 after the project has been created, I need to change something in the generated source code files since some of the APIs have changed. Is there a simple way to specify at project creation time the SDK I want to use explicitly?
Thank you in advance
I can't comment specifically on iPhone SDK 3.0 as it's covered under NDA; there's a forum for disclosed developers at devforums.apple.com. But Roger Nolan is half right and half wrong. He's half right in that when any SDK is updated, the examples and templates in that SDK are updated to exploit it. That is, the templates may specifically use the new APIs in that SDK, and the code might plain just not work with earlier SDKs.
That said, you can save project templates from earlier SDKs and install them in a local directory (like ~/Library/Application Support/Developer/Shared/Xcode/Project Templates) for use with later versions of Xcode. The project template format itself hasn't changed; templates should be forwards and backwards compatible, but the content of the templates is usually locked to the SDK version it ships with and later.
Mr. Nolan is half wrong about building against earlier OS versions with later SDKs. That's why the earlier SDK packages are provided with the later distributions (they're not there just to make the downloads take longer). You can deploy against older OS versions with a newer SDK by setting the Deployment Target build setting.
There is the minor detail in that you probably shouldn't deploy production applications produced by a pre-production toolchain. But once version N is officially released, you should be able to use its toolchain to build for N-1, N-2, etc.
Provided that you're not using any new features in the 3.0 API, you should be able to select the Active SDK from the dropdown menu on the upper left corner of your Xcode project window. Simply select "Device - 2.2.1" or "Simulator - 2.2.1"
Xcode defaults to the newest SDK installed, and I'm not aware of any method to change that behavior.
I made it a habit to set the base SDK to 2.0 in the project properties right after I create the project.
When using a Beta toolchain, you should install it alongside the latest released toolchain, not in place of it. Create your projects in the production toolchain, then open them with the beta toolchain to to do compatibility testing.
You will need the released toolchain anyway in order to do distribution builds. You should not build for distribution with a beta toolchain.
There is not according to Apple. Comments to my posting from Can Berk Güder say otherwise. I would not suggest following his example - it's a lottery hoping Apple can't see what you are doing or that you do not fall foul of a 3.0 defect.
You can use Xcode to build for earlier versions of the OS but if you need to build with multiple SDKs you should install them. Xcode supports multiple installations on a single machine and the install instructions document how to do it.
If you want to use the 3.0 SDK you can't built for OS 2.2.1 and submit that application to the app store - according to Apple's guidelines. They say that you must also install the 2.2.1 SDK and build with that. You can build 2.2 compatible apps but you are using beta tools which might introduce bugs.
It's one of those things that you can do as an intellectual exerxcise but, it's just not worth the risk for a real app.