BJ Homer bjhomer

Running echo "*.m diff=objc" >> .gitattributes in a git repo tells git to use the obj-c diff algorithm when running git diff. For the most part, this isn't much different from the standard diff algorithm. However, it adds one key benefit.

In a unified git diff, added lines are prefixed with a +, and removed lines are prefixed with a -. Unchanged lines are provided for context, and have no prefix. As added context, though, unified diffs have a @@-prefixed line at the beginning of each hunk. Minimally, the @@ lines specify which lines in the file are being changed. It can also contain a label, if git can determine an appropriate label for that section of code.

By default, the label on a hunk context line is the name of the enclosing C function. That works great for C-ish code, but completely misses Obj-C method signatures. As a result, when diffing Obj-C files, the context label is either empty, or falls back to the last C-ish declaration it could find. This is usually entirely useless.

Adding

	#! /usr/local/bin/macruby

	framework "ScriptingBridge"

	iTunes = SBApplication.applicationWithBundleIdentifier("com.apple.iTunes")

	iTunes.currentTrack.name

	// This is a useful bit of code for waiting for the results of an
	// asynchronous operation. It's especially useful in unit tests.
	// It keeps the run loop going, so it's not blocking delegate callbacks.

	BOOL waitForBlock(NSTimeInterval timeout,
	BOOL (^condition)(void)) {
	NSDate *timeoutDate = [NSDate dateWithTimeIntervalSinceNow:timeout];
	BOOL val = condition();
	while ( val == NO && [timeoutDate timeIntervalSinceNow] > 0 ) {
	[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:timeoutDate];


	#import <Foundation/Foundation.h>

	int main (int argc, const char * argv[])
	{

	@autoreleasepool {
	__block int x;

	NSLog(@"Address of x outside of block: %p", &x);

	@implementation UITableView (in_updateInBlocks)

	- (void)updateWithBlock:(void (^)(void))block {
	[self beginUpdates];
	block();
	[self endUpdates];
	}

	@end

	NSString *a = [NSString stringWithFormat:@"hi %@", @"there"];

	NSMutableString *b = [NSMutableString stringWithString:@"hi"];
	[b appendString:@" there"];

	NSLog(@"[a isEqual:b]: %d", [a isEqual:b]); // 1
	NSLog(@"[b isEqual:b]: %d", [b isEqual:a]); // 1

	NSMutableArray *a = [NSMutableArray array];
	[a addObject:a];
	NSLog(@"a: %@", a);

	#import <objc/runtime.h>
	#import <UIKit/UIKit.h>

	@interface UIWebView (HackishAccessoryHiding)
	@property (nonatomic, assign) BOOL hackishlyHidesInputAccessoryView;
	@end

	@implementation UIWebView (HackishAccessoryHiding)

	static const char * const hackishFixClassName = "UIWebBrowserViewMinusAccessoryView";

	- (void)setFoo:(BOOL)foo animated:(BOOL)animated {
	[super setFoo:foo animated:animated];

	dispatch_block_t changes = ^{
	if (foo) {
	someView.alpha = 1.0;
	}
	else {
	someView.alpha = 0.0;
	}

	NSManagedObjectContext *backgroundContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];

	NSManagedObjectContext *mainQueueContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];

	mainQueueContext.parentContext = backgroundContext;

	[backgroundContext performBlock:^{
	id someManagedObject = [backgroundContext objectWithID:someID];

	// Ensure that the object is not a fault