Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <h2>Abstract</h2> <p>To avoid map being shown prematurely, you should actually wait for the asynchronous update operation, and the cleanest pattern to do so will be <strong>delegation</strong>. Here is <a href="https://developer.apple.com/library/ios/documentation/general/conceptual/CocoaEncyclopedia/DelegatesandDataSources/DelegatesandDataSources.html" rel="nofollow">a nice Apple Doc</a> on its application in Cocoa/Cocoa Touch.</p> <p>Then it will work roughly like this:</p> <ol> <li>Pull-to-Refresh triggers location update.</li> <li>When location update is finished, <code>locationManager</code> notifies your controller and the controller presents a map.</li> </ol> <h2>How it can be done</h2> <p>I don't know the interface of your location manager class, but if it was CLLocationManager, it could have been done this way.</p> <p>CLLocationManager has a delegate property. Your view controller should: </p> <ol> <li>conform to <a href="https://developer.apple.com/library/ios/documentation/CoreLocation/Reference/CLLocationManagerDelegate_Protocol/CLLocationManagerDelegate/CLLocationManagerDelegate.html#//apple_ref/occ/intf/CLLocationManagerDelegate" rel="nofollow">CLLocationManagerDelegate protocol</a></li> <li>add itself as a delegate to <code>locationManager</code></li> <li>implement <code>locationManager:didUpdateLocations:</code> method — it gets called when location data has arrived and is ready for use.</li> </ol> <p>The implementation of this method should look like roughly this: </p> <pre><code>- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations { /* * shouldShowMap — BOOL property of View Controller, actually optional * but allowing to filter out handling of unwanted location updates * so they will not trigger map segue every time */ if (self.shouldShowMap) { [self performSegueWithIdentifier:@"showMap" sender:self]; self.shouldShowMap = NO; } // stop updating location — you need only one update, not a stream of consecutive updates [self.locationManager stopUpdatingLocation]; } </code></pre> <p>Your Pull-to-Refresh handler should look like this:</p> <pre><code>__typeof (&amp;*self) __weak weakSelf = self; [self.scrollView addPullToRefreshWithActionHandler:^ { self.shouldShowMap = YES; [weakSelf.locationManager startUpdatingLocation]; }]; </code></pre> <p>Hope it helped a bit. The best way to learn (well, in <em>most</em> cases) is to look at how stuff is implemented in system frameworks. Think in that direction and you'll definitely come up with a solution :)</p> <p>If you need clarifications, feel free to ask, I might have not explained it clearly enough.</p>
    singulars
    1. This table or related slice is empty.
    1. POCompleting a location fetch within 'pull to refresh'?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USivanmoskalev
    1. USivanmoskalev
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POCompleting a location fetch within 'pull to refresh'?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    1. COWow, superb answer Ivan. My location manager class is a custom class that uses CLLocationManager and updates to didUpdateLocation: are delivered to that class. I guess I need to restructure it slightly so that the updates are delivered to my controller so it knows when to present the map. I'll have go with your advice later today.
      singulars
      1. PO
      1. USAsh R
    2. COJust to come back and let you know, this worked perfectly. Thanks for your help with pointing me in the right direction.
      singulars
      1. PO
      1. USAsh R
    3. COGlad it helped you! Good luck with your app and happy coding :)
      singulars
      1. PO
      1. USivanmoskalev
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload