How to create a macro for object instantiation in Objective-C/ANSI C

Question

I hope I'm wording my question properly, but what I'm trying to do is actually rather trivial.

I have a bunch of code with static object instantiation that looks like this:

Foo *aFoo1 = [[[Foo alloc] init] autorelease];
[anArray addObject:aFoo1];
Foo *aFoo2 = [[[Foo alloc] init] autorelease];
[anArray addObject:aFoo2];

I simply want to move all of that instantiation + population of anArray into a separate header file, and just include the header file where it's needed without the overhead of creating a new class to manage these instantiations. I just want to include the header file and get access to anArray once it's done adding all of the above objects and stuff it somewhere else. Is there anyway I can turn the above into a macro? Ideally I'll have all of this in a database soon, query the db, and instantiate the result set. Either way, I'm curious what the answer to this is in the format it's currently written in.

Answer 1

My thought are to put the setup in a C function. You'd probably want to use two files:

//  Extra.h
// new file with descriptive header
NSArray* setupMyArray( ... );

-

//
// Extra.m
NSArray* setupMyArray( ... )
{
    NSMutableArray * anArray = [NSMutableArray arrayWithCapacity:0];
    // code to build array...
    //...
    return anArray;
}

Though I believe you'd be getting in to sketchy territory here. With Objective-C you are using an object orientated language. With C, you're not. It sounds like you want to build your objects in C and then use them in your class.

Answer 2

You could use the following:

#define CREATE_INSTANCE_AND_ADD_TO_ARRAY(TYPE, NAME, ARRAY) \
        TYPE * NAME = [[[TYPE alloc] init] autorelease];    \
        [ARRAY addObject:NAME]

Called like so:

CREATE_INSTANCE_AND_ADD_TO_ARRAY(Foo, aFoo1, anArray);
CREATE_INSTANCE_AND_ADD_TO_ARRAY(Foo, aFoo2, anArray);
...

Answer 3

Check the text macros in Xcode under Edit > Text Macros > Objective-C.

(You can even assign them keyboard shortcuts in Xcode preferences)