Refresh main view after choosing calendar and hitting back button - ios

Question

I followed this tutorial from AppCoda and I noticed that when I create another calendar, choose it (indicated by the checkmark beside it), then hit the Back button, the events in the main UIViewController view are not refreshed. I already added this code in my ViewController.m but nothing new happened:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
if (self.tblEvents == nil) {
NSLog(#"Your TableView becomes nil");
return;
}
[self.tblEvents reloadData];
}
Any ideas? Let me know if you need more information.
Edit:
.m
#import "MainViewController.h"
#import "AppDelegate.h"
#interface MainViewController ()
#property (nonatomic, strong) AppDelegate *appDelegate;
#property (nonatomic, strong) NSArray *arrEvents;
- (void)requestAccessToEvents;
- (void)loadEvents;
#end
#implementation MainViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
self.tblEvents.delegate = self;
self.tblEvents.dataSource = self;
[self performSelector:#selector(requestAccessToEvents) withObject:nil afterDelay:0.4];
[self performSelector:#selector(loadEvents) withObject:nil afterDelay:0.5];
[self.tblEvents reloadData];
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.tblEvents reloadData];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"idSegueEvent"]) {
EventViewController *eventViewController = [segue destinationViewController];
eventViewController.delegate = self;
}
}
#pragma mark - UITableView Delegate and Datasource method implementation
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSLog(#"%lu", (unsigned long)self.arrEvents.count);
return self.arrEvents.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"idCellEvent"];
// Get each single event.
EKEvent *event = [self.arrEvents objectAtIndex:indexPath.row];
// Set its title to the cell's text label.
cell.textLabel.text = event.title;
// Get the event start date as a string value.
NSString *startDateString = [self.appDelegate.eventManager getStringFromDate:event.startDate];
// Get the event end date as a string value.
NSString *endDateString = [self.appDelegate.eventManager getStringFromDate:event.endDate];
// Add the start and end date strings to the detail text label.
cell.detailTextLabel.text = [NSString stringWithFormat:#"%# - %#", startDateString, endDateString];
return cell;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 60.0;
}
- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
{
// Keep the identifier of the event that's about to be edited.
self.appDelegate.eventManager.selectedEventIdentifier = [[self.arrEvents objectAtIndex:indexPath.row] eventIdentifier];
// Perform the segue.
[self performSegueWithIdentifier:#"idSegueEvent" sender:self];
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the selected event.
[self.appDelegate.eventManager deleteEventWithIdentifier:[[self.arrEvents objectAtIndex:indexPath.row] eventIdentifier]];
// Reload all events and the table view.
[self loadEvents];
}
}
#pragma mark - EEventViewControllerDelegate method implementation
- (void)eventWasSuccessfullySaved
{
// Reload all events.
[self loadEvents];
}
#pragma mark - IBAction method implementation
- (IBAction)showCalendars:(id)sender
{
if (self.appDelegate.eventManager.eventsAccessGranted) {
[self performSegueWithIdentifier:#"idSegueCalendars" sender:self];
}
}
- (IBAction)createEvent:(id)sender
{
if (self.appDelegate.eventManager.eventsAccessGranted) {
[self performSegueWithIdentifier:#"idSegueEvent" sender:self];
}
}
#pragma mark - Private method implementation
- (void)requestAccessToEvents
{
[self.appDelegate.eventManager.eventStore requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError *error) {
if (error == nil) {
// Store the returned granted value.
self.appDelegate.eventManager.eventsAccessGranted = granted;
} else {
// In case of error, just log its description to the debugger.
NSLog(#"%#", [error localizedDescription]);
}
}];
}
- (void)loadEvents
{
if (self.appDelegate.eventManager.eventsAccessGranted) {
self.arrEvents = [self.appDelegate.eventManager getEventsOfSelectedCalendar];
[self.tblEvents reloadData];
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end

Answer 1

To make UITableView work you need to set the delegate and datasource object like this..
in you ViewController.m file try to add Delegate and DataSource like this.
#interface ViewController ()<UITableViewDelegate, UITableViewDataSource>
#end
now add these two lines in your view did load.
self.tblEvents.delegate = self;
self.tblEvents.dataSource = self;
And check the implimentation of you Data Source methods like this
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
//This method should return the number of rows you want to create in your tableView
return yourArray.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"yourCellIdentifier"];
//Now show what you want to show in your each cell? For Example you just want to show a simple text which is stored in you array.
cell.textLabel.text = [yourArray objectAtIndex:indexPath.row];
//indexPath.row is the numeric index number of each cell. This method will automatically execute exact the same number of time you return in above method.
return cell;
}
Now When your class/View Controller is open you might have zero data in your array and after some manipulation you got some data in your array Either by Call Web-Services/Loading from local Database/ by Passing Reference of array to next ViewController and on coming back to screen you want to refresh your TableView so now calling [tblEvents reloadData] will restart the process from numberOfRowsInSection method to cellForRowAtIndexPath method