Time-based query

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// Copyright 2017 Esri.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
// language governing permissions and limitations under the License.

using System;
using Esri.ArcGISRuntime;
using Esri.ArcGISRuntime.Data;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
using Foundation;
using UIKit;

namespace ArcGISRuntime.Samples.TimeBasedQuery
{
    [Register("TimeBasedQuery")]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Time-based query",
        category: "Layers",
        description: "Query data using a time extent. ",
        instructions: "Run the sample, and a subset of records will be displayed on the map.",
        tags: new[] { "query", "time", "time extent" })]
    public class TimeBasedQuery : UIViewController
    {
        // Hold references to UI controls.
        private MapView _myMapView;

        // Hold a URI pointing to the feature service.
        private readonly Uri _serviceUri = new Uri("https://sampleserver6.arcgisonline.com/arcgis/rest/services/Hurricanes/MapServer/0");

        // Hold a reference to the feature table used by the sample.
        private ServiceFeatureTable _myFeatureTable;

        public TimeBasedQuery()
        {
            Title = "Time-based query";
        }

        private void Initialize()
        {
            // Create a new map with oceans basemap.
            Map myMap = new Map(BasemapStyle.ArcGISOceans);

            // Create feature table for the hurricane feature service.
            _myFeatureTable = new ServiceFeatureTable(_serviceUri)
            {
                // Define the request mode.
                FeatureRequestMode = FeatureRequestMode.ManualCache
            };

            // When feature table is loaded, populate data.
            _myFeatureTable.Loaded += OnLoadedPopulateData;

            // Create FeatureLayer that uses the created table.
            FeatureLayer myFeatureLayer = new FeatureLayer(_myFeatureTable);

            // Add created layer to the map.
            myMap.OperationalLayers.Add(myFeatureLayer);

            // Assign the Map to the MapView.
            _myMapView.Map = myMap;
        }

        private async void OnLoadedPopulateData(object sender, EventArgs e)
        {
            // Unsubscribe from events.
            _myFeatureTable.Loaded -= OnLoadedPopulateData;

            // Create new query object that contains a basic 'include everything' clause.
            QueryParameters queryParameters = new QueryParameters
            {
                WhereClause = "1=1",
                // Restrict query with a time extent that covers the desired interval (beginning of time to September 16th, 2000).
                TimeExtent = new TimeExtent(new DateTime(1, 1, 1), new DateTime(2000, 9, 16))
            };

            // Create list of the fields that are returned from the service.
            string[] outputFields = {"*"};

            try
            {
                // Populate feature table with the data based on query.
                await _myFeatureTable.PopulateFromServiceAsync(queryParameters, true, outputFields);
            }
            catch (Exception ex)
            {
                new UIAlertView("Error", ex.ToString(), (IUIAlertViewDelegate) null, "OK", null).Show();
            }
        }

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();
            Initialize();
        }

        public override void LoadView()
        {
            // Create the views.
            View = new UIView() { BackgroundColor = ApplicationTheme.BackgroundColor };

            _myMapView = new MapView();
            _myMapView.TranslatesAutoresizingMaskIntoConstraints = false;

            // Add the views.
            View.AddSubviews(_myMapView);

            // Lay out the views.
            NSLayoutConstraint.ActivateConstraints(new[]
            {
                _myMapView.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor),
                _myMapView.BottomAnchor.ConstraintEqualTo(View.BottomAnchor),
                _myMapView.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor),
                _myMapView.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor)
            });
        }
    }
}