ALTableViewThing keeps track of table view rows and sections for you.

ALTableViewThing.h

//
//  ALTableViewThing.h
//
//  Created by Anthony Lobianco.
//  Copyright © 2016 All rights reserved.
//

#import <Foundation/Foundation.h>

// to make it easier for outside classes to know which values to cast to
// their specific enum type
//
typedef NSUInteger ALTableViewThingCastableInteger;

@class ALTableViewThing;

@protocol ALTableViewThingDelegate <NSObject>

/**
 *  The maximum possible number of rows in a section (e.g.
 *  ALTableViewFirstSectionRowsCount).
 *
 *  @param section The row's section.
 *
 *  @return The maximum number of rows.
 */
- (NSUInteger)tableViewThing:(ALTableViewThing *)thing maxNumberOfRowsInSection:(NSUInteger)section;

@optional

/**
 *  The maximum possible number of sections (e.g. ALTableViewSectionsCount).
 *
 *  @return The maximum number of sections. 1 if unimplemented.
 */
- (NSUInteger)tableViewThingMaxNumberOfSections:(ALTableViewThing *)thing;

/**
 *  Conditionally show or hide certain sections.
 *
 *  @param section The section to show/hide.
 *
 *  @return A bool. YES if unimplemented.
 */
- (BOOL)tableViewThing:(ALTableViewThing *)thing shouldShowSection:(NSUInteger)section;

/**
 *  Conditionally show or hide certain rows in a section.
 *
 *  @param row     The row to show/hide.
 *  @param section The row's section.
 *
 *  @return A bool. YES if unimplemented.
 */
- (BOOL)tableViewThing:(ALTableViewThing *)thing
         shouldShowRow:(NSUInteger)row
             inSection:(NSUInteger)section;

@end

@interface ALTableViewThing : NSObject

@property (nonatomic, weak) id<ALTableViewThingDelegate> delegate;

/**
 *  An array of NSNumbers that corresponds to the non-hidden sections
 *  based on the delegate methods above. The values can be mapped directly
 *  to your specific enum type.
 *
 *  @return An array of NSNumbers.
 */
- (NSArray <NSNumber *> *)sections;

/**
 *  Call this method in your tableView's `numberOfSections` delegate method.
 *
 *  @return The number of sections. This will NOT always be equal to sections.count.
 */
- (NSUInteger)numberOfSections;

/**
 *  An array of NSNumbers that corresponds to the non-hidden rows in a
 *  section based on the delegate methods above. The values can be mapped
 *  directly to your specific enum type.
 *
 *  @param section The row's section.
 *
 *  @return An array of NSNumbers.
 */
- (NSArray <NSNumber *> *)rowsInSection:(NSUInteger)section;

/**
 *  Call this method in your tableView's `numberOfRowsInSection:` delegate method.
 *
 *  @param section The row's section.
 *
 *  @return The number of rows. This WILL always be equal to rowsInSection:.count.
 */
- (NSUInteger)numberOfRowsInSection:(NSUInteger)section;

/**
 *  Use this method to map a row's value to its enum value
 *  based on any conditionally hidden rows.
 *
 *  @param row     The row to adjust.
 *  @param section The row's section.
 *
 *  @return The adjusted row value. Cast it to your specific enum type.
 */
- (ALTableViewThingCastableInteger)enumForRow:(NSUInteger)row inSection:(NSUInteger)section;

/**
 *  Use this method to map an enum value to a table view row
 *  based on any conditionally hidden rows.
 *
 *  @param enumVal The enum value
 *  @param section The enum's section.
 *
 *  @return The enum value's row number in the table view.
 */
- (NSUInteger)rowForEnum:(ALTableViewThingCastableInteger)enumVal inSection:(NSUInteger)section;

@end

ALTableViewThing.m

//
//  ALTableViewThing.m
//
//  Created by Anthony Lobianco.
//  Copyright © 2016 All rights reserved.
//

#import "ALTableViewThing.h"

@implementation ALTableViewThing

- (NSArray<NSNumber *> *)sections
{
    NSUInteger maxNumberOfSections = [self maxNumberOfSections];
    NSMutableArray<NSNumber *> *sections = [[NSMutableArray alloc] init];

    for (NSUInteger i = 0; i < maxNumberOfSections; i++)
    {
        if ([self shouldShowSection:i])
        {
            [sections addObject:@(i)];
        }
    }

    return [sections copy];
}

- (NSUInteger)numberOfSections
{
    // always return count of ALL sections, even if the delegate says a
    // certain section should be hidden. in that case, we'll return 0 rows
    // for that specific section.
    //
    return [self maxNumberOfSections];
}

- (NSArray<NSNumber *> *)rowsInSection:(NSUInteger)section
{
    if (![self shouldShowSection:section])
    {
        return 0;
    }

    NSUInteger maxNumberOfRows = [self.delegate tableViewThing:self maxNumberOfRowsInSection:section];
    NSMutableArray<NSNumber *> *rows = [[NSMutableArray alloc] init];

    for (NSUInteger i = 0; i < maxNumberOfRows; i++)
    {
        if ([self shouldShowRow:i inSection:section])
        {
            [rows addObject:@(i)];
        }
    }

    return [rows copy];
}

- (NSUInteger)numberOfRowsInSection:(NSUInteger)section
{
    return [self rowsInSection:section].count;
}

- (ALTableViewThingCastableInteger)enumForRow:(NSUInteger)row inSection:(NSUInteger)section
{
    NSParameterAssert([self shouldShowSection:section]);

    return [[self rowsInSection:section][row] integerValue];
}

- (NSUInteger)rowForEnum:(ALTableViewThingCastableInteger)enumVal inSection:(NSUInteger)section
{
    NSParameterAssert([self shouldShowSection:section]);

    NSUInteger numberOfRows = [self numberOfRowsInSection:section];
    NSUInteger finalEnumVal = numberOfRows;

    for (NSInteger i = (numberOfRows - 1); i >= 0; i--)
    {
        if (enumVal > [self enumForRow:i inSection:section])
        {
            break;
        }

        finalEnumVal = i;
    }

    return finalEnumVal;
}

#pragma mark - Internal methods

- (NSUInteger)maxNumberOfSections
{
    if ([self.delegate respondsToSelector:@selector(tableViewThingMaxNumberOfSections:)])
    {
        return [self.delegate tableViewThingMaxNumberOfSections:self];
    }

    return 1;
}

- (BOOL)shouldShowSection:(NSUInteger)section
{
    if ([self.delegate respondsToSelector:@selector(tableViewThing:shouldShowSection:)])
    {
        return [self.delegate tableViewThing:self shouldShowSection:section];
    }

    return YES;
}

- (BOOL)shouldShowRow:(NSUInteger)row inSection:(NSUInteger)section
{
    if ([self.delegate respondsToSelector:@selector(tableViewThing:shouldShowRow:inSection:)])
    {
        return [self.delegate tableViewThing:self shouldShowRow:row inSection:section];
    }

    return YES;
}

@end