Я новичок в разработке Objective-C, XCode и iPhone в целом, и у меня возникли некоторые проблемы с Core Data и NSXMLParser.
Следуя учебникам Apple, SeismicXML (для NSXMLParser) и учебнику «Основные данные на iPhone», я столкнулся с проблемой при назначении значений свойствам сущностей моих моделей управляемых объектов.
Чтобы объяснить ситуацию, мой код отличается от примера SeismicXML только использованием CoreData для назначения currentParsedCharacterData моим управляемым объектам, а не стандартным NSObject, который использует проект SeismicXML.
Ниже выводится описание моего управляемого объекта.
county = "-53.25354768,4.256547";
friendly = "-53.25354768,4.256547";
image = nil;
latitude = -53.253547684;
link = "-53.25354768,4.256547";
longitude = nil;
name = "-53.25354768,4.256547";
postcode = "-53.25354768,4.256547";
shopDescription = nil;
shopID = 0;
tag = "-53.25354768,4.256547";
tags = (
);
telephone = "-53.25354768,4.256547";
town = "-53.25354768,4.256547";
Кажется, что происходит то, что всем атрибутам / свойствам присвоено значение последнего узла в моем XML-фиде; которая бывает долгота, широта. Тем не менее, при регистрации проанализированных символьных данных во время присвоения свойства это ожидаемое (и правильное) значение, но при выводе описания этого объекта все строковые значения неверны, а числовые значения / иначе просто 0 или ноль.
Любые предложения будут чрезвычайно признательны. При необходимости я могу запустить меньший проект, который показывает это поведение с тем же XML-фидом, который я использую.
EDIT:
Вот сокращенный пример того, что я делаю, чтобы передать информацию в управляемый объект, что приводит к той же ошибке.
Для удобства у меня есть zip проекта http://willb.ro/CoreDataProblemExample.zip
Вывод отладки 2009-11-16 14: 31: 20.357
ShittyExample [4360: 4d07] Компания
Описание:
(юридическое лицо: Компания; id: 0x3f6e9e0
; данные: {
companyDescription = "Top Shop - ведущий бренд в розничной торговле
сек ";
companyID = 66136112;
name = "Top Shop - ведущий бренд в розничной торговле"; }) * +1022 *
//XML
<channel>
<company id="1">
<name>Top Shop</name>
<description>Top Shop are a leading brandname in the retail sector.</description>
</company>
</channel>
// FeedImporter.h
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
@class RootViewController, Company;
@interface FeedImporter : NSObject {
NSManagedObjectContext *managedObjectContext;
RootViewController *rootViewController;
NSMutableArray *companyList;
// for downloading the xml data
NSURLConnection *companyFeedConnection;
NSMutableData *companyData;
// these variables are used during parsing
Company *currentCompanyObject;
NSMutableArray *currentParseBatch;
NSUInteger parsedCompaniesCounter;
NSMutableString *currentParsedCharacterData;
BOOL accumulatingParsedCharacterData;
BOOL didAbortParsing;
}
@property (nonatomic, retain) NSManagedObjectContext *managedObjectContext;
@property (nonatomic, retain) RootViewController *rootViewController;
@property (nonatomic, retain) NSMutableArray *companyList;
@property (nonatomic, retain) NSURLConnection *companyFeedConnection;
@property (nonatomic, retain) NSMutableData *companyData;
@property (nonatomic, retain) Company *currentCompanyObject;
@property (nonatomic, retain) NSMutableString *currentParsedCharacterData;
@property (nonatomic, retain) NSMutableArray *currentParseBatch;
- (void)parseFeed;
- (void)addCompaniesToList:(NSArray *)companies;
- (void)handleError:(NSError *)error;
@end
// FeedImporter.m
#import "FeedImporter.h"
#import "RootViewController.h"
#import <CFNetwork/CFNetwork.h>
#import "Company.h"
@implementation FeedImporter
@synthesize managedObjectContext;
@synthesize rootViewController;
@synthesize companyList;
@synthesize companyFeedConnection;
@synthesize companyData;
@synthesize currentCompanyObject;
@synthesize currentParseBatch;
@synthesize currentParsedCharacterData;
- (void)dealloc {
[super dealloc];
[managedObjectContext release];
[rootViewController release];
[companyList release];
[companyFeedConnection release];
[companyData release];
[currentCompanyObject release];
[currentParseBatch release];
[currentParsedCharacterData release];
}
- (id)init {
if(self = [super init]) {
// Custom loading logic goes here..
}
return self;
}
- (void)parseFeed {
static NSString *feedURLString = @"http://willb.ro/companies.xml";
NSURLRequest *companyURLRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:feedURLString]];
self.companyFeedConnection = [[[NSURLConnection alloc] initWithRequest:companyURLRequest delegate:self] autorelease];
NSAssert(self.companyFeedConnection != nil, @"Failure to create URL connection.");
// Start the status bar network activity indicator. We'll turn it off when the connection finishes or experiences an error.
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
}
#pragma mark NSURLConnection delegate methods
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
self.companyData = [NSMutableData data];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[companyData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
if ([error code] == kCFURLErrorNotConnectedToInternet) {
// if we can identify the error, we can present a more precise message to the user.
NSDictionary *userInfo = [NSDictionary dictionaryWithObject:NSLocalizedString(@"No Connection Error", @"Error message displayed when not connected to the Internet.") forKey:NSLocalizedDescriptionKey];
NSError *noConnectionError = [NSError errorWithDomain:NSCocoaErrorDomain code:kCFURLErrorNotConnectedToInternet userInfo:userInfo];
[self handleError:noConnectionError];
} else {
// otherwise handle the error generically
[self handleError:error];
}
self.companyFeedConnection = nil;
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
self.companyFeedConnection = nil;
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[NSThread detachNewThreadSelector:@selector(parseCompanyData:) toTarget:self withObject:companyData];
self.companyData = nil;
}
- (void)parseCompanyData:(NSData *)data {
// You must create a autorelease pool for all secondary threads.
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
self.currentParseBatch = [NSMutableArray array];
self.currentParsedCharacterData = [NSMutableString string];
NSXMLParser *parser = [[NSXMLParser alloc] initWithData:data];
[parser setDelegate:self];
[parser parse];
if ([self.currentParseBatch count] > 0) {
[self performSelectorOnMainThread:@selector(addCompaniesToList:) withObject:self.currentParseBatch waitUntilDone:NO];
}
self.currentParseBatch = nil;
self.currentCompanyObject = nil;
self.currentParsedCharacterData = nil;
// Save to our MOC...
NSError *saveError;
if(![self.managedObjectContext save:&saveError]) {
// Handle MOM save error
NSLog(@"error while saving shop to managed object model");
NSError* error;
if(![[self managedObjectContext] save:&error]) {
NSLog(@"Failed to save to data store: %@", [error localizedDescription]);
NSArray* detailedErrors = [[error userInfo] objectForKey:NSDetailedErrorsKey];
if(detailedErrors != nil && [detailedErrors count] > 0) {
for(NSError* detailedError in detailedErrors) {
NSLog(@" DetailedError: %@", [detailedError userInfo]);
}
}
else {
NSLog(@" %@", [error userInfo]);
}
}
}
else
{
NSLog(@"MOC saved sucessfully");
}
[parser release];
[pool release];
}
#pragma mark Parser constants
// Limit the number of parsed companies to 50.
static const const NSUInteger kMaximumNumberOfCompaniesToParse = 50;
static NSUInteger const kSizeOfCompanyBatch = 10;
static NSString * const kChannelElementName = @"channel";
static NSString * const kCompanyElementName = @"company";
static NSString * const kCompanyNameElementName = @"name";
static NSString * const kCompanyDescriptionElementName = @"description";
- (void)addCompaniesToList:(NSArray *)companies {
[self.companyList addObjectsFromArray:companies];
// The table needs to be reloaded to reflect the new content of the list.
[rootViewController.tableView reloadData];
}
#pragma mark NSXMLParser delegate methods
- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict {
if (parsedCompaniesCounter >= kMaximumNumberOfCompaniesToParse) {
didAbortParsing = YES;
[parser abortParsing];
}
if ([elementName isEqualToString:kCompanyElementName]) {
Company *company = (Company *)[NSEntityDescription insertNewObjectForEntityForName:@"Company" inManagedObjectContext:self.managedObjectContext];
self.currentCompanyObject = company;
[company release];
int companyIDInt = (int)[attributeDict valueForKey:@"id"];
NSNumber *companyID = [NSNumber numberWithInt:companyIDInt];
[self.currentCompanyObject setCompanyID:companyID];
}
else if ([elementName isEqualToString:kCompanyElementName] || [elementName isEqualToString:kCompanyNameElementName] || [elementName isEqualToString:kCompanyDescriptionElementName]) {
accumulatingParsedCharacterData = YES;
[currentParsedCharacterData setString:@""];
}
}
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {
if ([elementName isEqualToString:kCompanyElementName]) {
//NSLog(@"currentEarthquakeObject: %@", currentEarthquakeObject);
[self.currentParseBatch addObject:self.currentCompanyObject];
parsedCompaniesCounter++;
if (parsedCompaniesCounter % kSizeOfCompanyBatch == 0) {
[self performSelectorOnMainThread:@selector(addCompaniesToList:) withObject:self.currentParseBatch waitUntilDone:NO];
self.currentParseBatch = [NSMutableArray array];
}
//NSLog(@"Reached end of company. Follows is a description of our company object: %@", [self.currentCompanyObject description]);
NSLog(@"Company Description: %@", [self.currentCompanyObject description]);
}
else if ([elementName isEqualToString:kCompanyNameElementName]) {
// Company Name
[self.currentCompanyObject setName:self.currentParsedCharacterData];
//NSLog(@"%@",self.currentParsedCharacterData);
}
else if ([elementName isEqualToString:kCompanyDescriptionElementName]) {
// Company Description
[self.currentCompanyObject setCompanyDescription:self.currentParsedCharacterData];
//NSLog(@"%@",self.currentParsedCharacterData);
}
accumulatingParsedCharacterData = NO;
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {
if (accumulatingParsedCharacterData) {
[self.currentParsedCharacterData appendString:string];
}
}
- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError {
if (didAbortParsing == NO) {
[self performSelectorOnMainThread:@selector(handleError:) withObject:parseError waitUntilDone:NO];
}
}
- (void)handleError:(NSError *)error {
NSString *errorMessage = [error localizedDescription];
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"Error Title", @"Title for alert displayed when download or parse error occurs.") message:errorMessage delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alertView show];
[alertView release];
}
@end