Why in Objective-C I can set instance variable inside a block:
@interface CMVServices : UIViewController
@property (nonatomic, strong) NSMutableArray *times;
@implementation CMVServices
@synthesize times=_times;
and set the _times instance variable inside a block:
(some code )
.
.
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
[_times addObjectsFromArray:objects];
}
but I can't in Swift?
class ViewController: UIViewController
var times :AnyObject[]!
query.findObjectsInBackgroundWithBlock { (objects: AnyObject[]!, error: NSError!) -> Void in
self.times = objects
}
The message is:
(AnyObject[]?) times = parent failed to evaluate: variable not available
Two things:
- Swift syntax for
Array
declarations has changed from AnyObject[]
to [AnyObject]
- If you're still in the class scope, simply use
times
instead of self.times
.
This works for me in XCode6-Beta4 in a Playground file:
import UIKit
class CMVServices : UIViewController {
var times : [AnyObject] = []
func testFunc() {
func findObjects(objects : [AnyObject]!, error : NSError!) {
times = objects
var test_str = "still evaluating in Playground here"
}
findObjects(["test", "string"], nil)
}
}
var test = CMVServices()
test.testFunc()
and for full-on test of closures themselves, this also works (again, in XCode6-Beta4):
import UIKit
class CMVServices : UIViewController {
var times: [AnyObject] = []
func testClosure() {
{ (objects : [AnyObject]!, error : NSError!) -> Void in
self.times = objects
NSLog("still evaluating")
}(["new", "test", "string"], nil)
}
}
var test = CMVServices()
test.testClosure()
test.times // ["new", "test", "string"]