Here’s what you’d want: Class theClass = NSClassFromString(classNameStr); id myObject = [[theClass alloc] init]; Note that you can’t use theClass as a type name (i.e. theClass *myObject). You’ll have to use id for that.
You have to import the runtime #import <objc/runtime.h>
To avoid overriding all of the delegate methods manually, you can use message forwarding. I just implemented the same thing using an intermediate proxy class as follows: MessageInterceptor.h @interface MessageInterceptor : NSObject { id receiver; id middleMan; } @property (nonatomic, assign) id receiver; @property (nonatomic, assign) id middleMan; @end MessageInterceptor.m @implementation MessageInterceptor @synthesize receiver; @synthesize … Read more
First, it’s hard to translate that code to Swift without knowing what you used that class object for in Objective-C. In Objective-C, class objects are objects, and the type Class can hold a pointer to any class object. However, when Objective-C APIs are bridged to Swift, the type Class is converted to AnyClass! in Swift, … Read more
It’s possible to add formal properties to a class via class_addProperty(): BOOL class_addProperty(Class cls, const char *name, const objc_property_attribute_t *attributes, unsigned int attributeCount) The first two parameters are self-explanatory. The third parameter is an array of property attributes, and each property attribute is a name-value pair which follow Objective-C type encodings for declared properties. Note … Read more
In addition to Buzzy’s answer, for debugging purposes you may use the -[NSObject _methodDescription] private method. Either in lldb: (lldb) po [[UIApplication sharedApplication] _methodDescription] or in code: @interface NSObject (Private) – (NSString*)_methodDescription; @end // Somewhere in the code: NSLog(@”%@”, [objectToInspect performSelector:@selector(_methodDescription)]); Output will look as following: <__NSArrayM: 0x7f9 ddc4359a0>: in __NSArrayM: Class Methods: + (BOOL) … Read more
I wrote that error message!• Either change the class name or don’t link against said library. How is your project configured? Is there anywhere where you explicitly link against SR? Or is it a product of linking against two static libraries that both already include SR? If the former, then stop linking against SR directly … Read more
super Essentially, it allows you to use the implementations of the current class’ superclass. For the gritty details of the Objective-C runtime: [super message] has the following meaning: When it encounters a method call, the compiler generates a call to one of the functions objc_msgSend, objc_msgSend_stret, objc_msgSendSuper, or objc_msgSendSuper_stret. Messages sent to an object’s superclass … Read more
It seems that the Apple engineer is right: the only to way to go is assembly code. Here are some usefull pointers to getting started: From the Objective-C runtime code: The i386 and x86_64 hand-crafted messenger assmbly stubs for the various messaging methods. An SO answer that provides an overview of the dispatching. A in-depth … Read more
objc_setAssociatedObject adds a key value store to each Objective-C object. It lets you store additional state for the object, not reflected in its instance variables. It’s really convenient when you want to store things belonging to an object outside of the main implementation. One of the main use cases is in categories where you cannot … Read more