I am using Core Data to show data in a table view, but I constantly encounter this problem :
Undefined symbols for architecture i386:
"_OBJC_CLASS_$_NSEntityDescription", referenced from: objc-class-ref in singleAppDelegate.o objc-class-ref in singleViewController.o "_OBJC_CLASS_$_NSFetchRequest", referenced from: objc-class-ref in singleViewController.o "_OBJC_CLASS_$_NSFetchedResultsController", referenced from: objc-class-ref in singleViewController.o "_OBJC_METACLASS_$_NSManagedObject", referenced from: _OBJC_METACLASS_$_Data in Data.o "_OBJC_CLASS_$_NSManagedObject", referenced from: _OBJC_CLASS_$_Data in Data.o
here is my singleViewController.m
#import "Data.h"
#import "singleViewController.h"
@interface singleViewController ()
@end
@implementation singleViewController
@synthesize managedObjectContext;
@synthesize fetchedResultsController = _fetchedResultsController;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
NSError *error;
if (![[self fetchedResultsController] performFetch:&error]) {
// Update to handle the error appropriately.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
exit(-1); // Fail
}
self.title = @"Core Data";
}
- (void)viewDidUnload
{
[super viewDidUnload];
self.fetchedResultsController = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
id sectionInfo =
[[_fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
Data *info = [_fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = info.title;
cell.detailTextLabel.text = info.content;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
// Configure the cell...
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
#pragma mark - fetchedResultsController
- (NSFetchedResultsController *)fetchedResultsController {
if (_fetchedResultsController != nil) {
return _fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription
entityForName:@"Data" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];
[fetchRequest setFetchBatchSize:20];
NSFetchedResultsController *theFetchedResultsController =
[[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:managedObjectContext sectionNameKeyPath:nil
cacheName:@"Root"];
self.fetchedResultsController = theFetchedResultsController;
_fetchedResultsController.delegate = self;
return _fetchedResultsController;
}
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
// The fetch controller is about to start sending change notifications, so prepare the table view for updates.
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath {
UITableView *tableView = self.tableView;
switch(type) {
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray
arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray
arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id )sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {
switch(type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
// The fetch controller has sent all current change notifications, so tell the table view to process all updates.
[self.tableView endUpdates];
}
@end
and here is my appdelegate.m
#import "Data.h"
#import "singleAppDelegate.h"
#import "singleAppDelegate.h"
@implementation singleAppDelegate
@synthesize window = _window;
@synthesize managedObjectContext = __managedObjectContext;
@synthesize managedObjectModel = __managedObjectModel;
@synthesize persistentStoreCoordinator = __persistentStoreCoordinator;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
NSManagedObjectContext *context = [self managedObjectContext];
Data *data = [NSEntityDescription
insertNewObjectForEntityForName:@"Data"
inManagedObjectContext:context];
data.title = @"title";
data.content = @"test content";
NSError *error;
if (![context save:&error]) {
NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
}
return YES;
}
and here is my data.m
@implementation Data
@dynamic title;
@dynamic content;
@end
Don't know what's wrong.
No output written to prog. Similarly, if a shared object is used to create a dynamic executable and leaves an unresolved symbol definition, an undefined symbol error results.
Why Is the Undefined Symbols for Architecture x86_64: Error Happening? This error is happening due to the lack of included values inside the declared statements in your code. The browser is going to render the information incorrectly and show this error, especially if you are working with Main and Similarity tools.
The error Undefined symbols for architecture arm64: "_OBJC_CLASS_$_SKAdImpression" during the iOS build usually happens if XCode or CocoaPods version is lower than required. To fix it update XCode to 12.5 or higher and CocoaPods to 1.10. 0 or higher.
You need to pass the values to the function Calculate. Variables x, y, z and function are not accessible outside the class and also u need a return type to the function so that you can get the output from the function Calculate.
Add CoreData.framework
to your target.
Choose your target, select Build Phases
and add CoreData.framework
in Link Binary With Libraries
.
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