Officially Apple let developers deploy apps that's compatible with iOS 3.0 to iOS 4.2. However there are some APIs and some hardware features that's not present in some devices or in some iOS versions.
However if you only have one testing device, and you want to try to install a clean iOS 3.0 to that, for testing purposes, what is the official way to do it? I tried looking all over Apple developer website and it does not give me anything.
I asked a similar question before: A TimeMachine taking my iDevice back to 3.1.2?
After that I did a thorough research on this topic. It finally turned out, that actually there is no official way for a developer to downgrade her or his own device back to an earlier iOS. Apple just doesn't allow that to happen.
However, in your code, there are many things you can do to make sure your app is supported in an old version iOS. Check this great post: http://cocoawithlove.com/2010/07/tips-tricks-for-conditional-ios3-ios32.html
If testing on the iOS Simulator is enough, you can achieve that by installing previous versions of the SDK which contains the older versions of iOS.
As for device, there is no quick way to switch between iOS versions on a single device.
I struggled with this for a while, and eventually gave up on downgrading and bought a used 1st gen iPod Touch, which can't be upgraded to 4.x so it's guaranteed to be 2.x or 3.x (2.x is easily upgraded to 3.x).
Now I test on that. Added benefit is that when testing on it you're at the same time checking the performance on a slower (slowest?) iOS device too.
Related
I searched for days, nothing found, no answer on apple dev forums, I want to be able to test my apps on older versions - on iOS Simulator!
I know - this is not the proper way of testing and not 100% reliable. But I can't afford getting another test-device with older iOS, aaand downgrading my existing devices seems to be a very tough task too - damn sure too tough for me...
Testing on iOS Simulator for 3.x versions will do enough good for those who didn't upgrade to 4.x yet and download my apps.
So please - anyone who was able to reactivate the older iOS Simulator SDKs on Lion / Xcode 4.1? - Don't tell me to set deployment target please :-)
THANKS!
Actually you can install xcode 3.2.x in Lion, and it's will automatic installed in "developer-old" floder. Your xcode 4.1 is still available.
I also want to reactivate the older iOS Simulator SDKs on Lion / Xcode 4.1. ;)
NotMyName posted blow in devforums.apple.com
By reverting back to OS X 10.6.8, and Xcode 4.02, apparently. :-(
Although it is worth noting that the Apple employees posting here have repeated a few times that this is an intended change, and one might guess that either the various simulator versions weren't particularly accurate on their API levels, or that it was just too much work to maintain. I seem to remember there being some bugs in the block implementations at the various levels, for starters.
There's also the often reported mantra, "The simulator is NOT an accurate way of testing your app's behavior."
You can't reactivate the iOS 3.x Simulator, you will need to install an older version of Xcode (one with the iOS 3.x SDK) along side Xcode 4.x (with the iOS 4.x SDK).
I am just about to upload my first app to appstore :-)
I have tested the app on an iPhone 3G (IOS 4.2) and my iPhone 4. What version of code should i upload and:
If i upload 4.2 to support iPhone 3G, will that cause any problems with newer phones?
If i upload the latest version of the code i guess iPhone 3G's will not be able to run it?
Is it worth while to still support iPhone 3G?
Can someone please recommend me what to do?
If you upload a version that the 3G does not support, then all 3G users will not be able to download the app.
If you upload a version that is supported by 3G, then only if the users have updated their firmware will be able to use the app.
In other words, the role of thumb is: upload the one that is tested on the latest firmware, but can be launched from as many firmware version as possible.
That might mean to just upload the one that is tested on the least firmware possible, but be careful because newer firmware versions might stop supporting certain APIs that you might have used, and then all newer (potential) customers will be locked out of your app.
If i upload 4.2 to support iPhone 3G, will that cause any problems with newer phones?
No.
If i upload the latest version of the code i guess iPhone 3G's will not be able to run it?
You need to compile for arm6 in addition to arm7 architecture.
Is it worth while to still support iPhone 3G?
That's a matter of opinion. This there any requirement for you specific app that requires a iPhone 3GS?
Choosing the latest ios as the deployment version is bad idea. iOS 4.3 isn't supported by Verizon devices, which means that you will lose a big portion of US users.
I believe most of apple's apps are using "iOS 3.1" as the deployment version, and i would recommend choosing the this as the lowest supported version.
iOS 3.1 is the last version supported by the original iphone, which guarantees that all users can use your app. Note it's not enougth to just pick 3.1 as the deployment version. you will have to test it with a REAL 3.1 firmware. There are a few guides on downgrading your iphone to 3.1, which is helpful for testing (such as http://lifehacker.com/5572003/how-to-downgrade-your-iphone-3g%5Bs%5D-from-ios-4-to-ios-313)
As Apple adds new APIs and new methods to APIs with every new iOS update or release and given that nowadays you can't even test on an iOS 3.x simulator, is there any way to test your iPhone app in older SDKs or to know what SDK level you are using through it?
Downgrading to an old Xcode with a 3.x simulator is not an option and, well, there are tons of methods introduced in, say, 4.2.
Has any one come up with a lib, script, tool, anything, that analyzes the code to show API usage?
The way most iOS developers do this is to keep around an old 1st or 2nd generation iPod Touch (or other old iPhone device) that hasn't been updated past the oldest iPhone OS version that they plan on supporting with their Deployment Target setting.
A cheap used iOS device, even with a scratched/cracked display or mostly dead battery, from eBay (et.al. or some neighbor or nephew who upgraded), might work.
Testing on an old device is actually a better and more accurate check than just testing with the Simulator, as the Simulator for various SDK versions supported APIs that the device at that OS level did not.
I am getting a fat binary when I go to upload, and I want to make sure that my application can run across 3.0, well even 2.0. Is there a specific way to make sure that this will show when I go to upload. I am not using any specific iOS 4 features, and I only have iOS 4 in my xCode. How can I test different iOS version?
The only way as I could think of is test your app on real old OS version devices. Since Apple prefers its users to upgrade to new OS version as soon as possible, they don't actually provide an official way for developers to test such backward compatibility.
Another relevant questions would be, "can I downgrade my device OS version to an old one, so that I can test my app on them?" I once did a research on SO and other Apple forums, and the result I got was NO, we developers don't have a way to "officially" downgrade our device OS version. Yes there are exceptions, you can try jail-breaking and then downgrading.
For jail-breaking / downgrading your OS version, check this post, A TimeMachine taking my iDevice back to 3.1.2? .
Edited: It's actually pretty easy to make sure that users with old OS versions can downloaded and install your app. All you need to do is set the Deployment Target in Xcode to the lowest OS version you want (iOS 3.0 would be the lowest in Xcode 3.2.5).
However, you need to bear in mind that such Deployment Target only ensures that your app can be downloaded and installed on such old version OS devices. They don't ensure compatibility during runtime. You still need to test your app on real old OS devices to ensure compatibility.
I dont think u need to worry about app version 3.0 below because it is not supported anymore. but how to test on different version, make sure change the iOS deployment target as Thomas refered.
There is no currently supported way to do this.
No current Simulator or Xcode tool will ensure that an app is completely compatible with an OS version older than the SDK used. The 2.0 SDK is not compatible with the current development tools. There is no officially supported way to downgrade a device.
Furthermore, Apple no longer even accepts app submissions that have a deployment target lower than 3.0.
Even most old 1st gen devices, if you can find one on eBay, have been upgraded to iOS 3.1.3. But if you have access to an old device running iOS 3.1.3, you can use that for testing. Many developers keep an old used iPod Touch around for just his purpose.
People with devices running something older than 3.1.3 are not only a really tiny percentage of the installed base, but are very unlikely to be still buying apps for that device. Even large developers with staff and legacy hardware available for this testing rarely waste the time on this market.
Look into Project -> Edit Project Settings -> iOS Deployment Target: 3.13. And then build?
Edit according to comment: You still need to ENSURE your code is within the runtime scope, i.e. do checks like 'respondstoselector' before calling methods in question.
I’ve installed Snow Leopard, have Xcode 3.2 and 3.0 iPhone SDK. I want my applications to run on 2.2.1, but the SDK is nowhere to be found in Xcode. I’ve set the deploy target to 2.2.1, but still I cannot be sure I am not using any 3.0-isms. (I’ve sent a sample application to my friend who still has 2.2.1 and it does not run, so it looks I really do use some 3.0 specific API.) How can make sure that my applications will run on 2.2.1? (Simulator also lists only 3.0 as version option.) I’d hate to check my sources manually for every call that might not have existed in 2.2.1.
See my question.
However, I think this is a bad situation that Apple has created for us. There really is no way to test against 2.x.x, if you, like me, have no iPhone 2.2s to test against. I actually bought a new 3Gs just so I could use the old 3G for testing. Stupidly though, when iTunes came up one day and asked if I wanted my phone updated to 3.0.1, I said yes, without realizing which phone I was updating.
I have tried, to no avail, to downgrade to 2.2.1, doing all the things like holding the home button and power for 10 seconds, etc., but I keep getting a baseband loading error.
I know Apple is trying hard to push everyone to 3.0, but not having the stats on how many users are still on the older OS, it seems prudent to keep supporting that OS. They should at least have kept 2.2.x support for the Simulator. I hate to release a 2.2.1 app based on whether I think I am using 3.0 calls or not, without actually testing it on 2.2.1.
OK, SDK 3.1 was released yesterday (September 9) and also contains SDK 2.2.1. You cannot build for the Simulator, only for the device, but most of the glaring 3.0-isms will appear as compile errors, which makes testing much easier.
Uninstall the SDK or Developer folder completley.
using Terminal execute: /Library/uninstall-devtools --mode=all, then restart, re-install new SDK.