Inspired by Jonathan Wight's CInvocationGrabber and Dave Dribin's DDInvocationGrabber, I realized Objective-C's newish support for blocks could make generating NSInvocations even easier.
Let's have a bake-off!
Manual:
NSInvocation *theInvocation = [NSInvocation invocationWithMethodSignature:[theString methodSignatureForSelector:@selector(insertString:atIndex:)]];
[theInvocation setSelector:@selector(insertString:atIndex:)];
[theInvocation setTarget:theString];
NSString *theFirstArgument = "Hello World";
[theInvocation setArgument:&theFirstArgument atIndex:2];
unsigned theSecondArgument = 42;
[theInvocation setArgument:&theFirstArgument atIndex:3];
Ick.
CInvocationGrabber:
CInvocationGrabber *theGrabber = [CInvocationGrabber invocationGrabber];
[[theGrabber prepareWithInvocationTarget:theString] insertString:@"Hello World" atIndex:42];
NSInvocation *theInvocation = [theGrabber invocation];
Much nicer.
NSInvocation+blocks:
NSInvocation *theInvocation = [NSInvocation jr_invocationWithTarget:theString block:^(id theString){
[theString insertString:@"Hello World" atIndex:42];
}];
Butter.