CoreData + UIViewController + UITableView - ios

Question

I would like to explain the most detailed the problem I'm facing.
Previously instead of the UIViewController i had directly a UITableViewController, the problem is that now i need to show more content in the view that just the tableview so i created a new view. Now i have a UIViewController that has: UIScrollView. Enside of it there are: 1. UIView + 1 UITableView
I'm using AutoLayout. And is working fine. The problem I'm facing is that since i switched to use this view I'm unable to display content in the table with coredata. I was able to do it without coredata but not with it.
In the interfacebuilder i set datasource and delegate to this UIViewController.
Header:
#import <UIKit/UIKit.h>
#interface ResultsExtraVC : UIViewController <UITableViewDelegate, UITableViewDataSource>
#property(nonatomic, strong) AGTCoreDataStack *model;
#property (strong, nonatomic) IBOutlet UILabel *labelRaceTime;
#property (strong, nonatomic) IBOutlet UILabel *labelTrackCondition;
#property (strong, nonatomic) IBOutlet UILabel *labelRaceStarttime;
#property (strong, nonatomic) IBOutlet UILabel *labelRaceMode;
#property (strong, nonatomic) IBOutlet UIScrollView *scrollView;
#property (weak, nonatomic) IBOutlet UITableView *tableView;
#property (strong, nonatomic) IBOutlet UIView *raceInfoView;
#property(nonatomic, strong)NSNumber *eventID;
#property(nonatomic, strong)NSNumber *sectionID;
#property(nonatomic, strong)NSNumber *elementID;
#property(nonatomic, strong)NSNumber *categoryID;
#end
Implementation:
#import "ResultsExtraVC.h"
#import "ResultsExtraCellVC.h"
#import "Result.h"
#import "Element.h"
#import "Section.h"
#import <CoreData/CoreData.h>
#interface ResultsExtraVC () <NSFetchedResultsControllerDelegate>
//Core data
#property (nonatomic,strong) NSManagedObjectContext* managedObjectContext;
#property (nonatomic, retain) NSFetchedResultsController *fetchedResultsController;
#end
static NSString * const cellIdentifier = #"resultsExrtaAltCell";
#implementation ResultsExtraVC
#synthesize managedObjectContext;
#synthesize fetchedResultsController = _fetchedResultsController;
#synthesize eventID, sectionID, elementID, categoryID, model;
- (void)viewDidLoad {
[super viewDidLoad];
managedObjectContext = self.model.context;
[self getResults];
NSLog(#"ElementName: %#", [self getElementName]);
NSLog(#"SectionName: %#", [self getSectionName]);
[self configureHeatInfo];
// Do any additional setup after loading the view.
}
- (void)viewDidUnload
{
[super viewDidUnload];
self.fetchedResultsController = nil;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - View Configuration
-(void) configureHeatInfo{
_scrollView.backgroundColor = [UIColor cyanColor];
_scrollView.translatesAutoresizingMaskIntoConstraints = NO;
_labelRaceTime.translatesAutoresizingMaskIntoConstraints = NO;
_labelRaceTime.text = #"Race time:\n10:00";
_labelRaceMode.translatesAutoresizingMaskIntoConstraints = NO;
_labelRaceMode.text = #"Mode: Groupstart";
_labelTrackCondition.translatesAutoresizingMaskIntoConstraints = NO;
_labelTrackCondition.text = #"Track Condition: Dry";
_labelRaceStarttime.translatesAutoresizingMaskIntoConstraints = NO;
_labelRaceStarttime.text = #"Starttime: 12.03.2016 11:09:10";
//self.tableView.translatesAutoresizingMaskIntoConstraints = NO;
/*self.tableView.dataSource = self;
self.tableView.delegate = self;*/
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return [[self.fetchedResultsController sections] count];
}
/*- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return 20;
}*/
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id sectionInfo = [[_fetchedResultsController sections] objectAtIndex:section];
#ifndef NDEBUG
NSLog(#"%s (line:%d) - Rows: %lu",__PRETTY_FUNCTION__,__LINE__, (unsigned long)[sectionInfo numberOfObjects]);
#endif
// Return the number of rows in the section.
return [sectionInfo numberOfObjects];
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
return [self basicCellAtIndexPath:indexPath];
}
- (ResultsExtraCellVC *)basicCellAtIndexPath:(NSIndexPath *)indexPath {
ResultsExtraCellVC *cell = [self.tableView dequeueReusableCellWithIdentifier:cellIdentifier];
// Using a cell identifier will allow your app to reuse cells as they come and go from the screen.
if (cell == nil) {
#ifndef NDEBUG
NSLog(#"%s (line:%d)",__PRETTY_FUNCTION__,__LINE__);
#endif
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"ResultsExtraCell" owner:self options:nil];
cell = (ResultsExtraCellVC *)[nib objectAtIndex:0];
}
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
- (void)configureCell:(ResultsExtraCellVC *)cell atIndexPath:(NSIndexPath *)indexPath {
#ifndef NDEBUG
NSLog(#"%s (line:%d)",__PRETTY_FUNCTION__,__LINE__);
#endif
Result *result = [_fetchedResultsController objectAtIndexPath:indexPath];
[cell.cellRankNr setText:[NSString stringWithFormat:#"%#",[result endposition]]];
[cell.cellName setText:[NSString stringWithFormat:#"%# %# (%#)",[result pilotprename], [result pilotname], [result carnumber]]];
[cell.cellResult setText:[NSString stringWithFormat:#"%#",NSLocalizedFormatString(#"LapsXnTimeX",[result rlaps],[result rendtime])]];
[cell.cellRace setText:[NSString stringWithFormat:#"%#",NSLocalizedFormatString(#"BestTimeXnAvgTimeX",[result rbesttime], [result rmediumtime])]];
}
-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
if ([tableView respondsToSelector:#selector(setSeparatorInset:)])
{
[tableView setSeparatorInset:UIEdgeInsetsZero];
}
if ([tableView respondsToSelector:#selector(setLayoutMargins:)])
{
[tableView setLayoutMargins:UIEdgeInsetsZero];
}
if ([cell respondsToSelector:#selector(setLayoutMargins:)])
{
[cell setLayoutMargins:UIEdgeInsetsZero];
}
}
-(NSString *)getElementName{
NSString *elementName = #"";
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:#"Elements" inManagedObjectContext:managedObjectContext];
NSFetchRequest *request = [[NSFetchRequest alloc] init] ;
[request setEntity:entityDescription];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"(eventid = %# AND sectionid = %# AND elementid = %# AND categoryid= %#)",eventID, sectionID, elementID, categoryID];
[request setPredicate:predicate]; //added this line later
NSArray *array = [managedObjectContext executeFetchRequest:request error:nil];
if([array count]> 0){
Element *element = [array lastObject];
elementName = [element name];
}
return elementName;
}
-(NSString *)getSectionName{
NSString *sectiontName = #"";
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:#"Sections" inManagedObjectContext:managedObjectContext];
NSFetchRequest *request = [[NSFetchRequest alloc] init] ;
[request setEntity:entityDescription];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"(eventid = %# AND sectionid = %#)",eventID, sectionID];
[request setPredicate:predicate]; //added this line later
NSArray *array = [managedObjectContext executeFetchRequest:request error:nil];
if([array count]> 0){
Section *section = [array lastObject];
sectiontName = [section name];
}
return sectiontName;
}
-(void)getResults{
// Initialize Fetch Request
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:#"Results"];
// Add Sort Descriptors
//[fetchRequest setSortDescriptors:#[[NSSortDescriptor sortDescriptorWithKey:#"endposition" ascending:YES]]];
//Predicate
NSPredicate *commentsPredicate = [NSPredicate predicateWithFormat:#"(eventid = %# AND sectionid = %# AND elementid = %#)",eventID, sectionID, elementID];
[fetchRequest setPredicate:commentsPredicate]; //added this line later
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"endposition"
ascending:YES];
NSArray *sortDescriptors = #[sortDescriptor];
[fetchRequest setSortDescriptors:sortDescriptors];
// Initialize Fetched Results Controller
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
// Configure Fetched Results Controller
[self.fetchedResultsController setDelegate:self];
// Perform Fetch
NSError *error = nil;
[self.fetchedResultsController performFetch:&error];
if (error) {
NSLog(#"Unable to perform fetch.");
NSLog(#"%#, %#", error, error.localizedDescription);
}
}
#pragma mark -
#pragma mark Fetched Results Controller Delegate Methods
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
[self.tableView beginUpdates];
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
[self.tableView endUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath {
switch (type) {
case NSFetchedResultsChangeInsert: {
[self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
case NSFetchedResultsChangeDelete: {
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
case NSFetchedResultsChangeUpdate: {
[self configureCell:(ResultsExtraCellVC *)[self.tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
}
case NSFetchedResultsChangeMove: {
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
}
#end
My View looks like this:
I tried to follow some tutorials as this is the first time i'm doing this with CoreData, previously i always used only UITableViewController.
I followed this: http://code.tutsplus.com/tutorials/core-data-from-scratch-more-nsfetchedresultscontroller--cms-21777
And also checked: CoreData TableView inside UIViewController
But with no success.
I would be great if someone can help me with the problem.
Thanks in advance

Answer 1

Maybe in code line
// Initialize Fetched Results Controller
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
the sectionNameKeyPath is missing? It must be one of the NSSortDescriptor keys.