Integration with ReactiveUI

I have released DynamicData.ReactiveUI which is a very simple adaptor layer to assist with binding dynamic data observables with reactiveui’s ReactiveList object.

Install from Nuget

Nuget

If you are not familiar with dynamic data and what it enables I suggest:

  1. Go through previous posts in the blog
  2. Download the example wpf app from github
  3. .

To cut to the chase, here’s an example. The code takes existing in-memory trade objects, transforms them into a view model proxy and updates the target reactive list object with the resulting change sets. It also pre-filters the data with live trades, applies a user entered filter, orders the resulting data and disposes the proxy when no longer required. Phew – all that in effectively one line of code.

I did the same example without using Reactive UI code see Trading Example Part 3. Integrate with UI where I have explained the code in greater detail

    public class RxUiViewer : ReactiveObject, IDisposable
    {
       //this is the target list which we will populate from the dynamic data stream
        private readonly ReactiveList<TradeProxy> _data = new ReactiveList<TradeProxy>();
        //the filter controller is used to inject filtering into a observable
        private readonly FilterController<Trade> _filter = new FilterController<Trade>();
        private readonly IDisposable _cleanUp;
        private string _searchText;

        public RxUiViewer(ITradeService tradeService)
        {
            //Change the filter when the user entered search text changes
            var filterApplier = this.WhenAnyValue(x => x.SearchText)
                .Throttle(TimeSpan.FromMilliseconds(250))
                .Subscribe(_ => ApplyFilter());
           
            ApplyFilter();

            var loader = tradeService.Trades
                .Connect(trade => trade.Status == TradeStatus.Live) //prefilter live trades only
                .Filter(_filter)    // apply user filter
                   //if targetting Net4 or Net45 platform can use parallelisation for transforms 'cause it's quicker
                .Transform(trade => new TradeProxy(trade), new ParallelisationOptions(ParallelType.Ordered, 5))
                .Sort(SortExpressionComparer<TradeProxy>.Descending(t => t.Timestamp), SortOptimisations.ComparesImmutableValuesOnly)
                .ObserveOn(RxApp.MainThreadScheduler)
                .Bind(_data)        //bind the results to the ReactiveList 
                .DisposeMany()      //since TradeProxy is disposable dispose when no longer required
                .Subscribe();

            _cleanUp = new CompositeDisposable(loader, _filter, filterApplier);
        }

        private void ApplyFilter()
        {
            if (string.IsNullOrEmpty(SearchText))
            {
                _filter.ChangeToIncludeAll();
            }
            else
            {
                _filter.Change(t => t.CurrencyPair.Contains(SearchText, StringComparison.OrdinalIgnoreCase) ||
                                    t.Customer.Contains(SearchText, StringComparison.OrdinalIgnoreCase));
            }
        }

        public string SearchText
        {
            get { return _searchText; }
            set { this.RaiseAndSetIfChanged(ref _searchText, value); }
        }

        public IReadOnlyReactiveList<TradeProxy> Data
        {
            get { return _data; }
        }

        public void Dispose()
        {
            _cleanUp.Dispose();
        }
    }

coupled with a little xaml can produce this

ReactiveUIImage

Very little code, but a very powerful example,

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2 thoughts on “Integration with ReactiveUI

  1. Pingback: What is Dynamic Data? | Dynamic Data

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