Populating table with 2 arrays - objective-c

Question

I'm trying to populate a tableview controller with objects from 2 different arrays but it crashes and gives this error
"Terminating app due to uncaught exception 'NSRangeException', reason: ' -[__NSArrayM objectAtIndex:]: index 1 beyond bounds [0 .. 0]"***
how do i fix this? below is my code:
(void)viewDidAppear:(BOOL)animated{
//[super viewDidAppear:<#animated#>];
NSManagedObjectContext *bookmanagedObjectContext = [self managedObjectContext];
NSFetchRequest *bookfetchRequest = [[NSFetchRequest alloc] initWithEntityName:#"Book"];
NSPredicate *bookpredicate =[NSPredicate predicateWithFormat:#" bookref.toproject contains[cd]%#",self.projectdb];
[bookfetchRequest setPredicate:bookpredicate];
NSSortDescriptor *booksortDescriptor = [[NSSortDescriptor alloc]initWithKey:#"authorSurname" ascending:YES];
NSArray *booksortDescriptors = [[NSArray alloc]initWithObjects:booksortDescriptor, nil];
[bookfetchRequest setSortDescriptors:booksortDescriptors];
self.BookrefArray = [[bookmanagedObjectContext executeFetchRequest:bookfetchRequest error:nil] mutableCopy];
NSManagedObjectContext *journalmanagedObjectContext = [self managedObjectContext];
NSFetchRequest *journalfetchRequest = [[NSFetchRequest alloc] initWithEntityName:#"Journal"];
NSPredicate *journalpredicate =[NSPredicate predicateWithFormat:#" journalref.toproj contains[cd]%#",self.projectdb];
[journalfetchRequest setPredicate:journalpredicate];
NSSortDescriptor *journalsortDescriptor = [[NSSortDescriptor alloc]initWithKey:#"surname" ascending:YES];
NSArray *journalsortDescriptors = [[NSArray alloc]initWithObjects:journalsortDescriptor, nil];
[journalfetchRequest setSortDescriptors:journalsortDescriptors];
self.JournalrefArray = [[journalmanagedObjectContext executeFetchRequest:journalfetchRequest error:nil] mutableCopy];
[self.tableView reloadData];}
(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
#warning Potentially incomplete method implementation.
// Return the number of sections.
return 1;
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
#warning Incomplete method implementation.
// Return the number of rows in the section.
return (self.BookrefArray.count + self.journalrefArray.count);
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cells";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
Journal *myjournal =[self.journalrefArray objectAtIndex:indexPath.row];
[cell.detailTextLabel setText:[myjournal valueForKey:#"journalname"]];
[cell.textLabel setText:[NSString stringWithFormat:#"%#, %#",[myjournal valueForKey:#"surname"],[myjournal valueForKey:#"firstname"]]];
Book *mybook =[self.BookrefArray objectAtIndex:indexPath.row];
// Configure the cell...
[cell.detailTextLabel setText:[mybook valueForKey:#"bookTitle"]];
[cell.textLabel setText:[NSString stringWithFormat:#"%#, %#",[mybook valueForKey:#"authorSurname"],[mybook valueForKey:#"authorOthernames"]]];
return cell;
}

Answer 1

You have this error because you try to access of an element of your array that is not exist.
In fact you says that your table has "table1.count + table2.count" elements and for each cell you try to get an element in your 2 tables with the current row.
For example, if table1 has 2 items and table2 has 5 items
, your tableView will have 7 rows and "cellForRowAtIndexPath" will be called 7 times. So for index 3 you will obtains this error because your table1 has only 2 items.
To solve the problem, you should get a book OR a journal in function of this row.
For example, you can try anything like this :
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cells";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
if (indexPath.row < self.BookrefArray.count)
{
Book *mybook =[self.BookrefArray objectAtIndex:indexPath.row];
// Configure your cell with a book
}
else
{
Journal *myjournal =[self.journalrefArray objectAtIndex:indexPath.row - self.BookrefArray.count];
// Configure your cell with a journal
}
return cell;
}
You can also change the order to display journals before books.

Answer 2

Answer :
You need to differentiate Book and Journal in -cellForRowAtIndexPath.
Explanation :
Your call for tableview's -cellForRowAtIndexPath will be dependent upon the number you're returning from tableview's -numberOfRowsInSection method.
So, for example, you've 3 objects in BookrefArray and 2 objects in journalrefArray, your tableview's -numberOfRowsInSection method will return 5 which means -cellForRowAtIndexPath will be called for 5 times.
Let's go through this line :
Journal *myjournal =[self.journalrefArray objectAtIndex:indexPath.row];
Here, it'll get indexPath.row = 5 for one case, and your journalrefArray contains only 2 objects. So, you're getting "index .. beyond bounds" error.
Update :
You can simply merge both the arrays into one.
[documentsArray addObjectsFromArray:self.BookrefArray];
[documentsArray addObjectsFromArray:self.journalrefArray];
and then in -cellForRowAtIndexPath, you can do something like this :
id document = [documentsArray objectAtIndex:indexPath.row];
if ([document isKindOfClass:Book])
{
Book *mybook = (Book *)document;
// Do something with mybook.
}
else
{
Journal *myjournal = (Journal *)document;
// Do something with myjournal.
}