我正在開發一個iPhone應用程序,用於收集來自3個獨立提要的數據。在applicationDidFinishLaunching
和applicationWillEnterForeground
並執行以下操作:來自遠程數據源的核心數據存儲
[self emptySchedule];
[self populateSchedule];
[self emptyPlayers];
[self populatePlayers];
[self emptyNews];
[self populateNews];
空的方法簡單地從核心數據中刪除信息,並填入方法調用各種Web JSON/XML提要添加信息返回到核心數據。它似乎這樣做非常快;但想知道這是否是保持信息在應用程序中最新的首選方法。
編輯:
只給一些背景,下面是用於空了幾個方法/填充:
因爲這主要是異步不會影響應用程序的啓動時間?
- (void) emptySchedule
{
NSFetchRequest * allEvents = [[NSFetchRequest alloc] init];
[allEvents setEntity:[NSEntityDescription entityForName:@"Event" inManagedObjectContext:self.managedObjectContext]];
[allEvents setIncludesPropertyValues:NO]; //only fetch the managedObjectID
NSError * error = nil;
NSArray * events = [self.managedObjectContext executeFetchRequest:allEvents error:&error];
//error handling goes here
for (NSManagedObject * event in events) {
[self.managedObjectContext deleteObject:event];
}
NSError *saveError = nil;
[self.managedObjectContext save:&saveError];
}
-(void)populateSchedule
{
NSURL *url = [NSURL URLWithString:SCHEDULE_FEED_URL];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id schedule)
{
for (NSDictionary *campEvent in schedule)
{
Event *event = nil;
event = [NSEntityDescription insertNewObjectForEntityForName:@"Event" inManagedObjectContext:self.managedObjectContext];
event.eventName = [campEvent valueForKeyPath:@"eventName"];
event.ticketsRequired = [campEvent valueForKeyPath:@"ticketsRequired"];
event.location = [campEvent valueForKeyPath:@"location"];
event.practiceStart = [NSDate dateWithTimeIntervalSince1970:[[campEvent valueForKeyPath:@"practiceStart"] doubleValue]];
event.practiceEnd = [NSDate dateWithTimeIntervalSince1970:[[campEvent valueForKeyPath:@"practiceEnd"] doubleValue]];
}
NSError *saveError = nil;
//Save inserts
[self.managedObjectContext save:&saveError];
//Notify other objects of this
[[NSNotificationCenter defaultCenter] postNotificationName:@"populateSchedule" object:nil];
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Error" message:@"Error Retrieving Data. Please try again later." delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil];
[alert show];
}];
[operation start];
}
對於*保持信息在應用程序中的最新狀態,您有什麼意義*?謝謝。 – 2012-07-05 17:22:52
這些提要從各種來源提取信息。我將這些信息存儲在覈心數據中,當應用程序啓動或進入前臺時,我再次獲取數據。 – 2012-07-05 17:26:58