objective-c-blocks

This question already has answers here : NSOperationQueue serial FIFO queue (3 answers) Closed 5 years ago . I'm having trouble understanding the way NSOperationQueue works. Say I have: NSOperationQueue *queue = [[NSOperationQueue alloc] init]; queue.maxConcurrentOperationCount=1; [queue addOperationWithBlock:^{ [someObject someSelector]; }]; [queue addOperationWithBlock:^{ [someObject anotherSelector]; }]; The second block is being called even before the first block finishes - the opposite of what I want. I tried using – performSelectorOnMainThread:withObject:waitUntilDone: instead, but the

I have a Kiwi spec file that looks something like this: #import "Kiwi.h" #import "MyCollection.h" SPEC_BEGIN(CollectionSpec) describe(@"Collection starting with no objects", ^{ MyCollection *collection = [MyCollection new]; context(@"then adding 1 object", ^{ MyObject *object = [MyObject new]; [collection addObject:object]; it(@"has 1 object", ^{ [collection shouldNotBeNil]; [collection.objects shouldNotBeNil]; [[theValue(collection.objects.count) should] equal:theValue(1)]; //failing test }); context(@"then removing 1 object", ^{ [collection removeObject:object]; it(@"has 0 objects", ^{ [

I've had it with memory leaks arising from block retain cycles. I would just like a simple rule that I can apply to my code to make sure I avoid them. On the other hand, I don't want to update half of my code base base to __weak pointers without it being necessary. Here is what I have up to now: There can be no memory leaks when you use the following: dispatch_async(queue, ^{...}); // GCD call. [Foo bar:^{...}]; // Class "+" methods with completion block. However, these cases will cause block retain cycle memory leaks for sure: self.myPropertyBlock = ^{ self; }; _myInstanceVariableBlock = ^{

The part of a method that I am trying to test is as follows: - (void)configureTableFooterView { dispatch_async(dispatch_get_main_queue(), ^{ self.tableView.tableFooterView = nil; if ([self.parser.resultSet isLastPage]) { return; } }); } I have written the unit test as follows: - (void)testTableFooterViewConfigurationAfterLastPageLoaded { id mockTableView = OCMClassMock([GMGFlatTableView class]); OCMExpect([mockTableView setTableFooterView:[OCMArg isNil]]); id resultSet = OCMClassMock([GMGResultSetInfo class]); OCMStub([resultSet isLastPage]).andReturn(YES); OCMStub([self.mockParser resultSet])

I'm trying to write a helper class to allow our app to support both UIAlertAction and UIAlertView . However, when writing the alertView:clickedButtonAtIndex: method for the UIAlertViewDelegate , I came across this issue: I see no way to execute the code in the handler block of a UIAlertAction . I'm trying to do this by keeping an array of UIAlertAction s in a property called handlers @property (nonatomic, strong) NSArray *handlers; and then implement a delegate like such: - (void) alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex { UIAlertAction *action = self

I'm creating a barButton which when pressed should set the editing mode of a UITableView to yes. Here's my code: self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle: @"Edit" style: self.navigationController.navigationItem.leftBarButtonItem.style target: self action: ]; What I don't understand is what I need to put as an argument for the action part so that I can execute a code block there. I could easily enough put @selector(someMethod) but I'm only executing one or two lines and creating another method is pretty pointless. Thanks for any help! Further to pgb's