objective-c-blocks

I am trying to delete multiple tables in a single operation from sqlite. I tried separating it by semicolon but it didn't work out as expected. Here is my current code : NSString *query = @"DELETE from Friends;DELETE from Stream;DELETE from Version"; I need some guidance on what could the problem be here, or if I am missing something. To make an atomic operation out of multiple statements, use a transaction: BEGIN; DELETE FROM Friends; DELETE FROM Stream; DELETE FROM Version; COMMIT; You have to execute these five commands one by one if you're using sqlite3_prepare_v2 ; with sqlite3_exec , you

UPDATE | I've uploaded a sample project using the panel and crashing here: http://w3style.co.uk/~d11wtq/BlocksCrash.tar.gz (I know the "Choose..." button does nothing, I've not implemented it yet). UPDATE 2 | Just discovered I don't even have to invoke anything on newFilePanel in order to cause a crash, I merely need to use it in a statement. This also causes a crash: [newFilePanel beginSheetModalForWindow:[windowController window] completionHandler:^(NSInteger result) { newFilePanel; // Do nothing, just use the variable in an expression }]; It appears the last thing dumped to the console is

This question already has an answer here: Blocks retain cycle from naming convention? 1 answer I've written the following category for NSOperationBlock @implementation NSOperationQueue (Extensions) -(void)addAsynchronousOperationWithBlock:(void (^)(block))operationBlock { dispatch_semaphore_t semaphore = dispatch_semaphore_create(0); block signal = ^ { dispatch_semaphore_signal(semaphore); }; [self addOperationWithBlock:^{ operationBlock(signal); dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER); dispatch_release(semaphore); }]; } @end it seems to work properly but when I call it (as

I'm figuring out the right mechanism to pass data from UITableViewCell s to a UIableViewController (or UIViewController ). Searching within stackoverflow I found different ways to do this and finally I found a mechanism that works well but I don't know if it could be a valid approach. This is the scenario. First, I created a custom cell (associated with a xib interface), named DataTableViewCell , that extends UITableViewCell . This cell has some outlet to display (and modify) data and an addictional property called index like the following: @property (nonatomic, copy) NSIndexPath* index; This