How to reloadData in class which implements UITableViewDataSource protocol

Question

I have a class which implements UITableViewDelegate protocol and there is another class which handles data i.e. it implements UITableViewDataSource protocol.

@interface TableViewClass : UITableViewController <UITableViewDelegate>

@interface TableDataSource : NSObject <UITableViewDataSource>

and I'm setting the TableViewClass as delegate and TableDataSource as datasource

id datasource = [[TableDataSource alloc] init]
[self.tableView setDelegate:self];
[self.tableView setDataSource:dataSource];

I am fetching the data off an asynchronous server call in init method of TableDataSource class which populates an array and determines the number of rows/sections in table.

But before the call returns back some result, the numberOfSectionsInTableView and numberOfRowsInSection are executed resulting in 0 rows and 0 sections, hence an empty table.

I thought of putting the [self.tableView reloadData] in callBack but I do not have access to tableView in datasource class. Can anybody guide me how to reloadData in tableView through datasource class as I might need it later to refresh data too. Thanks

Answer 1

To solve this quickly, you can add an @property on TableDataSource for the UITableView.

// TableDataSource.h
@interface TableDataSource : NSObject <UITableViewDataSource>{
    UITableView *tableView;
}

@property(retain)UITableView *tableView;

@end

// TableDataSource.m
@implementation TableDataSource
@synthesize tableView;

- (void)dealloc{
    self.tableView = nil;
}

@end

Now, set the property when you create the DataSource:

// UITableViewController.m
TableDataSource* datasource = [[TableDataSource alloc] init]
[datasource setTableView:self.tableView]
[self.tableView setDelegate:self];
[self.tableView setDataSource:dataSource];

When you need to reload the data from the DataSource, you can now do:

[self.tableView reloadData];