iOS13 PostFix #8: workaround for missing objc classes(ObjCClassNotFoundException)24 Dec 2019 | binding postfix
Apple altogether with introducing new APIs also keeps refactoring existing one. In this case it results in part of API being extracted from class and moved to newly introduced class. And this class is being used as new super. Result class will have schema when super class introduced later than child. This makes problem when running code on iOS older than super was introduced. Bright example:
// since ios 4.1 @interface GKPlayer : GKBasePlayer // but // since ios 10.0 @interface GKBasePlayer : NSObject
RoboVM bro bridge resolves native classes for binded java ones and if class is missing it throws
Existing bindings corrected this behaviour by manually specifying
NSObject as super. Also it might require manual copying methods from unsupported super. With iOS13 there are lot of such classes with supers younger than children. Manual corrections becomes problematic and also this leads to lost of common parent class.
The fix (workaround)
How it expected to work:
it should allow to have possibly missing objc classes as parent;
For each missing obj-c class case instead of throwing
ObjCClassNotFoundException new objc class will be registered. It will inherit expected super of missing class. Java class will use this as its shadowed objc class.
it should not allow direct instantiation of missing classes.
New class for missing one will override
+alloc method and will throw
ObjCClassNotFoundException. This makes impossible direct instantiation of missing classes.
It will work as objc runtime doesn’t bother about java side and all native objc methods invocations results in
Code is delivered as PR442
- PostFix #1: Generic class arguments and @Block parameters
- PostFix #2: Adding support for non-static @Bridge method in enums classes
- PostFix #3: Support for @Block member in structs
- PostFix #4: Compilation failed on @Bridge annotate covariant return synthetic method
- PostFix #5: Support for Struct.offsetOf in structs
- PostFix #6: Fixes to Network framework bindings
- PostFix #7: bindings for ios13.2
- PostFix #9: experimental and formal bitcode support
- PostFix #10: glkit – missing functions (static inline now)