Parse Framework iOS: Query for header by date

Question

Scenario

I have an app that allows users to post suggestions onto a PFQueryTableViewController. I am using the parse.com framework and each post is created with an attached "date" 00/00/00 and "time" 00:00PM.

What I Need

To have sections in the tableview set up for each day ("date" object on the Post) - With the 00/00/00 displayed as the title for the section.

Question

Does anyone know how to design something like this?

Answer 1

There was something posted on the old parse.com forums for something similar to this:

https://parse.com/questions/using-pfquerytableviewcontroller-for-uitableview-sections

It is for sports, but you can easily modify it to match your needs.

Here is the code if the link dies:

SectionedQueryTableViewController.h

@interface SectionedQueryTableViewController : PFQueryTableViewController

@end

SectionedQueryTableViewController.m

#import "SectionedQueryTableViewController.h"

@interface SectionedQueryTableViewController()
@property (nonatomic, retain) NSMutableDictionary *sections;
@property (nonatomic, retain) NSMutableDictionary *sectionToSportTypeMap;
@end

@implementation SectionedQueryTableViewController
@synthesize sections = _sections;
@synthesize sectionToSportTypeMap = _sectionToSportTypeMap;

- (id)initWithStyle:(UITableViewStyle)style {
    self = [super initWithStyle:style];
    if (self) {
        self.className = @"Athlete";
        self.textKey = @"name";
        self.pullToRefreshEnabled = YES;
        self.paginationEnabled = YES;
        self.objectsPerPage = 25;
        self.sections = [NSMutableDictionary dictionary];
        self.sectionToSportTypeMap = [NSMutableDictionary dictionary];
    }
    return self;
}


#pragma mark - PFQueryTableViewController

- (void)objectsDidLoad:(NSError *)error {
    [super objectsDidLoad:error];

    // This method is called every time objects are loaded from Parse via the PFQuery

    [self.sections removeAllObjects];
    [self.sectionToSportTypeMap removeAllObjects];

    NSInteger section = 0;
    NSInteger rowIndex = 0;
    for (PFObject *object in self.objects) {
        NSString *sportType = [object objectForKey:@"sportType"];
        NSMutableArray *objectsInSection = [self.sections objectForKey:sportType];
        if (!objectsInSection) {
            objectsInSection = [NSMutableArray array];

            // this is the first time we see this sportType - increment the section index
            [self.sectionToSportTypeMap setObject:sportType forKey:[NSNumber numberWithInt:section++]];
        }

        [objectsInSection addObject:[NSNumber numberWithInt:rowIndex++]];
        [self.sections setObject:objectsInSection forKey:sportType];
    }
}

- (PFQuery *)queryForTable {
    PFQuery *query = [PFQuery queryWithClassName:self.className];

    // If Pull To Refresh is enabled, query against the network by default.
    if (self.pullToRefreshEnabled) {
        query.cachePolicy = kPFCachePolicyNetworkOnly;
    }

    // If no objects are loaded in memory, we look to the cache first to fill the table
    // and then subsequently do a query against the network.
    if (self.objects.count == 0) {
        query.cachePolicy = kPFCachePolicyCacheThenNetwork;
    }

    // Order by sport type
    [query orderByAscending:@"sportType"];
    return query;
}

- (PFObject *)objectAtIndexPath:(NSIndexPath *)indexPath {
    NSString *sportType = [self sportTypeForSection:indexPath.section];
    NSArray *rowIndecesInSection = [self.sections objectForKey:sportType];
    NSNumber *rowIndex = [rowIndecesInSection objectAtIndex:indexPath.row];
    return [self.objects objectAtIndex:[rowIndex intValue]];
}

#pragma mark - UITableViewDataSource

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return self.sections.allKeys.count;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    NSString *sportType = [self sportTypeForSection:section];
    NSArray *rowIndecesInSection = [self.sections objectForKey:sportType];
    return rowIndecesInSection.count;
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
    NSString *sportType = [self sportTypeForSection:section];
    return sportType;
}


#pragma mark - UITableViewDelegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    [super tableView:tableView didSelectRowAtIndexPath:indexPath];

    PFObject *selectedObject = [self objectAtIndexPath:indexPath];
}


#pragma mark - ()

- (NSString *)sportTypeForSection:(NSInteger)section {
    return [self.sectionToSportTypeMap objectForKey:[NSNumber numberWithInt:section]];
}

@end