Populate tableview from NSDictionary

Question

I have an NSDictionary received from a json request that looks like this:

RESULT : (
    {
    Id1 = 138;
    lat = "45.5292910";
    long = "-73.6241500";
    order = "2343YY3"

},
    {
    Id1 = 137;
    lat = "45.5292910";
    long = "-73.6241500";
    order = "2343YY3"

}, etc.

I want to display it in a TableView (CellforRowAtIndexPath), so I obtain the data as NSArray. The method seems inefficient as each key Id1, lat, long, etc is created as an NSArray so that I can display them each with: [self.data1 objectAtIndex:indexPath.row]; [self.data2 objectAtIndex:indexPath.row], etc.

How can I achieve the same thing without creating and using 4 NSArrays? Can I use a single NSArray or the NSMutableDictionary which stores the data?

UPDATED:

When the TableView loads, it is initially empty but I have a button on that same VC that loads a modal view of a form. When I load the form and then dismiss it returning to the TableView, the data is LOADED! Could you suggest what I am missing?

Answer 1

Yes you can use a single array. The trick is to create an array with each array entry holding a dictionary. Then you query the array to populate your tableview.

E.g.: If your array is a property called tableData and you have custom tableview cell called CustomCell then your code might look something like the following:

- (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.
    return [self.tableData count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"CustomCell";

    CustomCell *cell = (CustomCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    // Configure the cell...
    cell.latitude.text = [[self.tableData objectAtIndex:indexPath.row] objectForKey: @"lat"];
    cell.longitude.text = [[self.tableData objectAtIndex:indexPath.row] objectForKey:@"long"];
    // continue configuration etc..
    return cell;
}

Similarly, if you have multiple sections in your tableview then you will construct an array of arrays, with each sub-array containing the dictionaries for that section. The code to populate the tableview would look something similar to the following:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    // Return the number of sections.
    return [self.tableData count];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    // Return the number of rows in the section.
    return [[self.tableData objectAtIndex:section] count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"CustomCell";

    CustomCell *cell = (CustomCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    // Configure the cell...
    cell.latitude.text = [[[self.tableData objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] objectForKey: @"lat"];
    cell.longitude.text = [[[self.tableData objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] objectForKey:@"long"];
    // continue configuration etc..
    return cell;
}

TL;DR; Take your dictionaries created from your JSON data and put them in an array. Then query the array to populate the tableview.

Answer 2

You can do as follows:

// main_data = Store your JSON array as "array of dictionaries"

Then in cellForRowAtIndexPath do as follows:

NSDictionary *obj = [main_data objectAtIndex: indexPath.row];
// Access values as follows:
[obj objectForKey: @"Id1"]
[obj objectForKey: @"lat"]
...
...