如何使用RxSwift更新UITableViewCell？

Question

I learned example in the demo to create a UITableView and render cells.

In my opinion, items is viewModel, I want to request some data across network by using Alamofire or other library. When I get the response, How can I update the cell's text relevant?

In the other words, I want to bind viewModel to Cells. When the model's data changed, cell's content could changed automatically.

I have a idea is: create a Observable sequence for the cell's content (bind to cell).When the server response data, it call function tableView.reloadRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Top) . But this seems not a grace or good method.

So, hope some can help me :)

let items = Observable.just([
            "First Item",
            "Second Item",
            "Third Item"
        ])

    items
        .bindTo(tableView.rx_itemsWithCellIdentifier("Cell", cellType: UITableViewCell.self)) { (row, element, cell) in
            cell.textLabel?.text = "\(element) @ row \(row)"
            /* to do some binding or something else ? */
        }
        .addDisposableTo(disposeBag)


    tableView
        .rx_modelSelected(String)
        .subscribeNext { value in
            DefaultWireframe.presentAlert("Tapped `\(value)`")
        }
        .addDisposableTo(disposeBag)

Answer 1

Your client (Alomofire, ...) will have some like this:

func searchSomething() -> Observable<[YourModel]>

In the viewModel you will have the items property:

private(set) lazy var items : Observable<[YourModel]> = 
    self.client.searchSomething()
        .observeOn(MainScheduler.instance)
        .shareReplay(1)

And then, in the viewController :

tableView.dataSource = nil

// Bind the items to the table view data source
viewModel.items
    .bindTo(tableView.rx.items) { tableView, index, item in
        let cell: UITableViewCell = tableView.dequeueReusableCell(withIdentifier: "Cell")
        cell.textLabel?.text = item.title  // if item.title is a String

            return cell
    }
    .addDisposableTo(disposeBag)

Answer 2

you can try this

//important!
var items = Variable([YourModel]()) //empty  now

let cellIdentifier = NSStringFromClass(YourCell.self).components(separatedBy: ".")[1]

tableView.register(YourCell.classForCoder(), forCellReuseIdentifier: cellIdentifier)

_ = tableView.rx.setDelegate(self)

items.asObservable().bindTo(tableView.rx.items(cellIdentifier: cellIdentifier, cellType: YourCell.self)){
            (index,model,cell) in
            cell.detailTextLabel?.text = model.age
            }.addDisposableTo(dispose)
 //just like your network  request      
 DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
            self.items.value = [1,3,4,5,6,7,8] //has value now
}
//it works fine for me

Answer 3

change to Variable and change value

let items =  Variable([
        "First Item",
        "Second Item",
        "Third Item"
    ])

items
    .bindTo(tableView.rx_itemsWithCellIdentifier("Cell", cellType: UITableViewCell.self)) { (row, element, cell) in
        cell.textLabel?.text = "\(element) @ row \(row)"
        /* to do some binding or something else ? */
    }
    .addDisposableTo(disposeBag)


tableView
    .rx_modelSelected(String)
    .subscribeNext { value in
        DefaultWireframe.presentAlert("Tapped `\(value)`")
        items.value = ["item 1", "item 2"] //your updated array
    }
    .addDisposableTo(disposeBag)