UITableView Swift Combine static section with dynamics ones

Question

The main idea is to have all sections in an array or you may suggest other solution to build a table. I had this code below to prepare data for a table:

enum ExerciseSection {
    case empty
    case exerciseGroup(group: ExerciseGroup)
}

struct ExerciseGroup {
    var muscleGroupName: String
    var exercises: [ExerciseEntity]
    var selectedExercisesIndexes: [Int]
}

As you see using this ExerciseSection enum I can simple check if the section is static empty or it should display some muscle group name. Also Group contains exercises. So I can simple a build needed cell.

So I prepare data for my table by creating an array of ExerciseSection.

In this concert example my empty cell is a cell which redirect me to the other screen.

Looks like this:

[empty cell for section 0, group for section 1, group for section 2... and etc]

Now I changed mind of preparing my own sections and instead I started using CoreStore.monitorSectionedList

typealias ListEntityType = ExerciseEntity

let monitor = CoreStore.monitorSectionedList(
    From<ListEntityType>()
    .sectionBy(#keyPath(ListEntityType.muscle.name)) { (sectionName) -> String? in
        "\(String(describing: sectionName)) years old"
    }
    .orderBy(.ascending(\.name))
    )

So now my data is grouped automatically by relationships muscle name.

I can simple access instance of monitor and see how many sections it has and how many rows it has for appropriate section. Pretty awesome!

But my question now how can I combine monitor object which has all needed info about grouped objects and about groups with my static cells.

In my example above I have the firs element empty cell for section 0 but monitor already has section 0 as well.

So I need to have a hack to add 1 + which I really don't like as this is a magical number and some day it will surprise me.

func numberOfSections(in tableView: UITableView) -> Int {
     return 1 + (monitor.numberOfSections() ?? 0) // My static section + monitor sections
}

In the previous time I just had array of all my sections [ExerciseSection] so there is no needs to control code via 1 +

I need to glue somehow my static section info and monitor.sections

You may never used CoreStore before, so never mind you can just think about monitor object as an object that has some groups to represent sections and these groups has items to represent rows. So I just need to combine it.

In my case you can simple see that the static cell is a first one item in the list but I am looking for flexible solution I even can't imagine how to show static cell at the middle of list for example.

Maybe as a solution I can loop through monitor objects and create my enum from it. Not sure.

Answer 1

Hmm... The "easiest" way would be to have a computed property sections or similar.

Something along the lines of

var sections: [ExerciseSection] {
    return [.empty] + monitor.sections
}

But if the monitor doesn't have a direct way to get sections, then maybe the best way would be to simply have a list of "pre-sections".

let presections: [ExerciseSection] = [.empty]

func numberOfSections(in tableView: UITableView) -> Int {
     return presections.count + (monitor.numberOfSections() ?? 0) // My static section + monitor sections
}

You could add a couple of functions to help you such as

func section(at indexPath: IndexPath) -> ExerciseSection {
    guard indexPath.section >= presections.count else {
        return presections[indexPath.section]
    }
    return monitor.section(at: indexPath.section - presections.count)
}

You do mention looping through the monitor objects, and this can be nice for smaller datasets. The downside is that you suddenly store data in memory. I don't know how the monitor works.

With Realm I've done this but only stored the id and maybe some simple data for each row.