ygmtx / NSInvocation-Block

NSInvocation category to create NSInvocation with block

NSInvocation-Block

Objective

NSInvocation-Block is a NSInvocation category to create NSInvocation with block

Usage

Given

void (^myBlock)(id, NSString*, NSArray*) = ^(id obj1, NSString* name, NSArray* array) {
  NSLog(@"%@",@"Hey!");
};

We can create an invocation:

NSInvocation* inv = [NSInvocation invocationWithBlock:myBlock];

Or with arguments:

NSInvocation* inv = [NSInvocation invocationWithBlockAndArguments:myBlock,[NSObject new],@"Hello",@[@1,@2,@3]];

Known issues

1. Arguments of struct, union or C-style array type are not supported yet.

Update

I attempted to add support for struct and union.

NSUInteger valueSizeInByte = 0;
NSUInteger align = 0;
NSGetSizeAndAlignment(argType, &valueSizeInByte, &align);
void* buffer = malloc(valueSizeInByte);
if (align == 4) {
  for (int ii = 0; ii < valueSizeInByte / align ; ii++) {
    UInt32 val = va_arg(args,UInt32);
    memcpy(((UInt32*)buffer+ii), &val, align);
  }
}else if(align == 8){
  for (int ii = 0; ii < valueSizeInByte / align ; ii++) {
    UInt64 val = va_arg(args,UInt64);
    memcpy(((UInt64*)buffer+ii), &val, align);
  }
}
[invocation setArgument:buffer atIndex:1 + i];
free(buffer);

Anyhow, code only worked for struct on device! Besides, the use of buffer in the code snippet is not safe. Actually we can't see implementation of NSInvoation, do not know how it behaves when calling -[NSInvoation retainArguments].

In a word, I won't add this snippet before i figure it out.