Best Practices: Difference between revisions

Latest revision as of 03:42, 29 May 2021

Use the following guidelines to avoid your package or app being fragile and to increase the chances of it being accepted by a community host.

Applications and Tweaks

NSHomeDirectory() doesn't guarantee that it will return /var/mobile, especially from within sandboxed processes.
- If your code is running as root, use extra caution when writing files that mobile can access - you might break the file's access permissions.
- App Store apps will return their sandbox data path from NSHomeDirectory().
See Cydia Substrate Pitfalls for additional guidelines regarding tweaks.
You should consider the UDID deprecated like Apple has for some time, but if you need the device's UDID, use libMobileGestalt.dylib.
If you need to use singletons, see singleton pattern for advice.
If you need to respring from a tweak and you are targeting iOS 6 - 7, kill backboardd instead of SpringBoard. Killing SpringBoard has been known to cause some issues regarding the backlight. For iOS 8 and newer, if possible, use SBSRelaunchAction or -[HBRespringController respring] from libcephei for a more appropriate way to respring. Simply killing the processes can destroy battery usage data (the feature since iOS 8).

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 == Applications and Tweaks ==
-* Avoid referring to /var/mobile directly - use NSHomeDirectory() if your code is running as mobile!
+* <code>NSHomeDirectory()</code> doesn't guarantee that it will return <code>/var/mobile</code>, especially from within sandboxed processes.
 ** If your code is running as root, use extra caution when writing files that mobile can access - you might break the file's access permissions.
-* See [[MobileSubstrate Pitfalls]] for additional guidelines regarding tweaks.
+** App Store apps will return their sandbox data path from <code>NSHomeDirectory()</code>.
+* See [[Cydia Substrate Pitfalls]] for additional guidelines regarding tweaks.
-== Packages ==
+* You should consider the UDID deprecated like Apple has for some time, but if you need the device's UDID, use [[libMobileGestalt.dylib]].
-* Do not create mobile-owned files and/or directories in your package. Stay out of mobile's home directory!
+* If you need to use singletons, see [[singleton pattern]] for advice.
-** All package files are installed as root. Your software should create any required files or directories at runtime.
+* If you need to respring from a tweak and you are targeting iOS 6 - 7, kill backboardd instead of SpringBoard. Killing SpringBoard has been known to cause some issues regarding the backlight. For iOS 8 and newer, if possible, use <code>[[FBSSystemService#Relaunch SpringBoard with relaunch URL|SBSRelaunchAction]]</code> or <code>-[HBRespringController respring]</code> from [https://github.com/hbang/libcephei/blob/master/HBRespringController.x libcephei] for a more appropriate way to respring. Simply killing the processes can destroy battery usage data (the feature since iOS 8).
-** This is doubly important for preferences. A user's preferences do not belong in a package: if preferences are stored in the package, they will be overwritten when you release an update, and deleted when the user uninstalls your software (even temporarily!)
-* Do not use postinst/preinst/extrainst_ for file management purposes!
-** Do not store in the package files or directories that your software could create.
-** Do not enforce permissions that your package should contain. dpkg uses an expressive packaging format that has support for permissions, ownership, and links. Use that support!