Question

I wish to display table section with date as the section title and name of book in the row. I’m all lost at how to use a NSDictionary to load data into section and rows. Therefore my codes are all screwed up 🙁 Can anyone offer some help, with some sample codes as a guide? My NSMutableArray is as followed:

(
        {
        BIBNo = 187882;
        date = "14/08/2012";
        itemSequence = 000010;
        name = "Increasing confidence / Philippa Davies.";
        noOfRenewal = 0;
        number = 000187907;
        status = "Normal Loan";
        time = "24:00";
        type = Loans;
    },
        {
        BIBNo = 291054;
        date = "14/08/2012";
        itemSequence = 000010;
        name = "iPhone application development for IOS 4 / Duncan Campbell.";
        noOfRenewal = 2;
        number = 000291054;
        status = "Normal Loan";
        time = "24:00";
        type = Loans;
    },
        {
        BIBNo = 244441;
        date = "15/08/2012";
        itemSequence = 000010;
        name = "Coach : lessons on the game of life / Michael Lewis.";
        noOfRenewal = 1;
        number = 000244441;
        status = "Normal Loan";
        time = "24:00";
        type = Loans;
    },
        {
        BIBNo = 290408;
        date = "15/08/2012";
        itemSequence = 000010;
        name = "Sams teach yourself iPhone application development in 24 hours / John Ray.";
        noOfRenewal = 3;
        number = 000290408;
        status = "Normal Loan";
        time = "24:00";
        type = Loans;
    },
        {
        BIBNo = 161816;
        date = "16/08/2012";
        itemSequence = 000010;
        name = "Malaysian Q & As / compiled by Survey & Interview Department ; illustrations by Exodus.";
        noOfRenewal = 1;
        number = 000161817;
        status = "Normal Loan";
        time = "24:00";
        type = Loans;
    },
        {
        BIBNo = 187883;
        date = "16/08/2012";
        itemSequence = 000010;
        name = "Positive thinking / Susan Quilliam.";
        noOfRenewal = 3;
        number = 000187899;
        status = "Normal Loan";
        time = "24:00";
        type = Loans;
    }
)

How do i actually re-add the objects into NSDictionary so that objects with the same date would be stored together to be displayed as rows in the section? Please offer me some advice thanks! T_T

Answer 1

To process your data you would need to do something like

NSMutableDictionary *dataSource = [[NSMutableDictionary alloc] init]; // This would need to be an ivar

for (NSDictionary *rawItem in rawItems) {
    NSString *date = [rawItem objectForKey:@"date"]; // Store in the dictionary using the data as the key

    NSMutableArray *section = [dataSource objectForKey:date]; // Grab the section that corresponds to the date

    if (!section) { // If there is no section then create one and add it to the dataSource
        section = [[NSMutableArray alloc] init];
        [dataSource setObject:section forKey:date];
    }

    [section addObject:rawItem]; // add your object
}

self.dataSource = dataSource;

Then to get the section title

NSArray *sections =[[self.dataSource allKeys] sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];
return [sections objectAtIndexPath:indexPath.section];

Then to get a row in a section

NSString *sectionTitle = // get the section title calling the above code
NSArray *items = [self.dataSource objectForKey:sectionTitle];

return [items objectAtIndex:indexPath.row];