RxSwift - Filter data from tableview from UIPickerView

Question

i try to filter data from my table View. When i select one value from picker View, The data suppose to filter based on the category and the table view should reload with filtered data. here i attach the code

struct RecipeList {

let id: Int
let catid: String
let name: String
let description: String
let ingredient: String
let step: String
let image: String
let img: NSData
//static var dataSource = BehaviorRelay(value: [RecipeList]())
static var items = [RecipeList]()
}

here how i fetch data to table View

func setupCellConfiguration() {
    
  let recipeList = Observable.just(RecipeList.items)
    recipeList
        .bind(to: tableView
            .rx
            .items(cellIdentifier: RecipeListCell.Identifier,
                   cellType: RecipeListCell.self)) { row, recipe, cell in
                    cell.configureWithRecipe(recipe: recipe)
    }
    .disposed(by: disposeBag)
}

Here how pick event on picker view

func setupRecipeTypePickerView(textField: UITextField) {
    
    let pickerView = UIPickerView()
    pickerView.selectRow(Int(self.selectedRecipeType) ?? 0, inComponent: 0, animated: false)
    textField.inputView = pickerView
    let recipeType = Observable.of(RecipeType.items)
    recipeType.bind(to: pickerView.rx.itemTitles) { (row, element) in
        return "\(element.name)"
    }
    .disposed(by: disposeBag)
    pickerView.rx.itemSelected
        .subscribe { (event) in
            switch event {
            case .next(let selected):
                
                selected.row == 0 ? (self.isFilter = false) : (self.isFilter = true)
                let recipeType = RecipeType.items[selected.row]
                textField.text = recipeType.name
                self.selectedRecipeType = recipeType.id
                RecipeList.items.append(contentsOf: RecipeList.items.filter({$0.catid == recipeType.id}))

            default:
                break
            }
    }
    .disposed(by: disposeBag)
    
}

Here how append data from Core data to Model

    func getRecipeList() {
    RecipeList.items.removeAll()
    
    guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else { return }
    
    let managedContext = appDelegate.persistentContainer.viewContext
    
    let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: Common.ENTITYNAME)

    do {
        let result = try managedContext.fetch(fetchRequest)
        for data in result as! [NSManagedObject] {
            let id = data.value(forKey: "id") as! Int
            let catid = data.value(forKey: "catid") as? String ?? "1"
            let name = data.value(forKey: "name") as! String
            let description = data.value(forKey: "rdescription") as! String
            let ingredient = data.value(forKey: "ingredient") as! String
            let step = data.value(forKey: "step") as! String
            let image = data.value(forKey: "image") as! String
            let img = data.value(forKey: "img") as! NSData

            let recipe = RecipeList(id: id, catid: catid, name: name, description: description, ingredient: ingredient, step: step, image: image, img: img)
            RecipeList.items.append(recipe)
        }
       // RecipeList.dataSource.accept(RecipeList.items)
    } catch {
        
        print("Failed")
    }
}

I try alot solution from multiple sources, seems does not work. This is my first day learning RXSwift. Usually i didnt use RXSwift, i just simply, create variable for filtered data, then rereload the tableView

Answer 1

The missing bit in your code is that you are just emitting the RecipeList.items and then completing. You have to emit a new value from recipeList every time you want the table view to reload.

Try something like this instead:

class Example: UIViewController {
    var tableView: UITableView!
    var textField: UITextField!
    let disposeBag = DisposeBag()

    override func viewDidLoad() {
        super.viewDidLoad()

        let pickerView = createPickerView()

        textField.inputView = pickerView
        configureTextField(pickerView: pickerView)
        configureTableView(pickerView: pickerView)
    }

    func createPickerView() -> UIPickerView {
        let pickerView = UIPickerView()
        Observable.just(RecipeType.items)
            .bind(to: pickerView.rx.itemTitles) { row, element in
                return element.name
            }
            .disposed(by: disposeBag)
        return pickerView
    }

    func configureTextField(pickerView: UIPickerView) {
        pickerView.rx.itemSelected
            .map { RecipeType.items[$0.row].name }
            .bind(to: textField.rx.text)
            .disposed(by: disposeBag)
    }

    func configureTableView(pickerView: UIPickerView) {
        let recipeList = Observable.just(RecipeList.items)
        Observable.combineLatest(recipeList, pickerView.rx.itemSelected.map { $0.row })
            .map { (list, selected) -> [RecipeList] in
                guard selected != 0 else { return list }
                let recipeType = RecipeType.items[selected]
                return list.filter { $0.catid == recipeType.id }
            }
            .bind(to: tableView.rx.items(cellIdentifier: RecipeListCell.Identifier,
                       cellType: RecipeListCell.self)) { row, recipe, cell in
                        cell.configureWithRecipe(recipe: recipe)
            }
            .disposed(by: disposeBag)
    }
}