Delete features (feature service)

View on GitHubSample viewer app

Delete features from an online feature service.

screenshot

Use case

Sometimes users may want to delete features from an online feature service.

How to use the sample

  • click on a feature on the Map
  • click on the delete button

How it works

  1. Create a ServiceFeatureTable object from a URL.
  2. Create a FeatureLayer from the service feature table.
  3. Select features from the feature layer via selectFeaturesAsync().
  4. Remove the selected features from the table using deleteFeaturesAsync().
  5. Update the table on the server using applyEditsAsync().

Relevant API

  • Feature
  • FeatureLayer
  • ServiceFeatureTable

Tags

deletion, feature, online, Service, table

Sample Code

DeleteFeaturesFeatureService.cppDeleteFeaturesFeatureService.cppDeleteFeaturesFeatureService.hDeleteFeaturesFeatureService.qml
Use dark colors for code blocksCopy
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
// [WriteFile Name=DeleteFeaturesFeatureService, Category=EditData]
// [Legal]
// Copyright 2016 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.
// [Legal]

#ifdef PCH_BUILD
#include "pch.hpp"
#endif // PCH_BUILD

#include "DeleteFeaturesFeatureService.h"

#include "Map.h"
#include "MapQuickView.h"
#include "Basemap.h"
#include "Viewpoint.h"
#include "Point.h"
#include "SpatialReference.h"
#include "ServiceFeatureTable.h"
#include "FeatureLayer.h"
#include "Feature.h"
#include "ArcGISFeature.h"
#include "FeatureEditResult.h"
#include "FeatureQueryResult.h"
#include "MapViewTypes.h"
#include "MapTypes.h"
#include "LayerListModel.h"
#include "IdentifyLayerResult.h"
#include "QueryParameters.h"
#include "AttributeListModel.h"
#include "FeatureIterator.h"
#include "CalloutData.h"
#include "Envelope.h"

#include <QFuture>
#include <QUrl>
#include <QUuid>
#include <QMouseEvent>
#include <QString>
#include <memory>

using namespace Esri::ArcGISRuntime;

DeleteFeaturesFeatureService::DeleteFeaturesFeatureService(QQuickItem* parent) :
  QQuickItem(parent)
{
}

DeleteFeaturesFeatureService::~DeleteFeaturesFeatureService() = default;

void DeleteFeaturesFeatureService::init()
{
  qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
  qmlRegisterType<DeleteFeaturesFeatureService>("Esri.Samples", 1, 0, "DeleteFeaturesFeatureServiceSample");
  qmlRegisterUncreatableType<CalloutData>("Esri.Samples", 1, 0, "CalloutData", "CalloutData is an uncreatable type");
}

void DeleteFeaturesFeatureService::componentComplete()
{
  QQuickItem::componentComplete();

  // find QML MapView component
  m_mapView = findChild<MapQuickView*>("mapView");
  m_mapView->setWrapAroundMode(WrapAroundMode::Disabled);

  // create a Map by passing in the Basemap
  m_map = new Map(BasemapStyle::ArcGISStreets, this);
  m_map->setInitialViewpoint(Viewpoint(Point(-10800000, 4500000, SpatialReference(102100)), 3e7));

  // set map on the map view
  m_mapView->setMap(m_map);

  // create the ServiceFeatureTable
  m_featureTable = new ServiceFeatureTable(QUrl("https://sampleserver6.arcgisonline.com/arcgis/rest/services/DamageAssessment/FeatureServer/0"), this);

  // create the FeatureLayer with the ServiceFeatureTable and add it to the Map
  m_featureLayer = new FeatureLayer(m_featureTable, this);
  m_map->operationalLayers()->append(m_featureLayer);

  connectSignals();
}

void DeleteFeaturesFeatureService::connectSignals()
{
  // connect to the mouse clicked signal on the MapQuickView
  connect(m_mapView, &MapQuickView::mouseClicked, this, [this](QMouseEvent& mouseEvent)
  {
    // first clear the selection
    m_featureLayer->clearSelection();

    // set the properties for qml
    emit hideWindow();

    //! [DeleteFeaturesFeatureService identify feature]
    // call identify on the map view
    constexpr double tolerance = 5.0;
    constexpr int maxResults = 1;
    constexpr bool returnPopupsOnly = false;
    m_mapView->identifyLayerAsync(m_featureLayer, mouseEvent.position(), tolerance, returnPopupsOnly, maxResults).then(this, [this](IdentifyLayerResult* rawIdentifyResult)
    {
      onIdentifyLayerCompleted_(rawIdentifyResult);
    });
    //! [DeleteFeaturesFeatureService identify feature]

    // connect to the viewpoint changed signal on the MapQuickView
    connect(m_mapView, &MapQuickView::viewpointChanged, this, [this]()
    {
      m_featureLayer->clearSelection();
      emit hideWindow();
    });
  });
}

void DeleteFeaturesFeatureService::deleteSelectedFeature()
{
  m_featureTable->deleteFeatureAsync(m_selectedFeature).then(this, [this]()
  {
    // handle the completion of applyEditsAsync from the ServiceFeatureTable
    m_featureTable->applyEditsAsync().then(this, [](const QList<FeatureEditResult*>& featureEditResults)
    {
      // obtain the first item in the list
      FeatureEditResult* featureEditResult = featureEditResults.isEmpty() ? nullptr : featureEditResults.first();
      // check if there were errors, and if not, log the new object ID
      if (featureEditResult && !featureEditResult->isCompletedWithErrors())
        qDebug() << "Successfully deleted Object ID:" << featureEditResult->objectId();
      else
        qDebug() << "Apply edits error.";

      qDeleteAll(featureEditResults);
    });
  });
}

void DeleteFeaturesFeatureService::onIdentifyLayerCompleted_(IdentifyLayerResult* rawIdentifyResult)
{
  // Deletes rawIdentifyResult instance when we leave scope.
  auto identifyResult = std::unique_ptr<IdentifyLayerResult>(rawIdentifyResult);

  if (!identifyResult)
  {
    return;
  }

  if (identifyResult->geoElements().isEmpty())
  {
    return;
  }

  // delete selected feature member if not nullptr
  if (m_selectedFeature)
  {
    delete m_selectedFeature;
    m_selectedFeature = nullptr;
  }

  GeoElement* element = identifyResult->geoElements().at(0);
  if (!element)
  {
    return;
  }

  // select the item in the result
  QueryParameters query;
  query.setObjectIds(QList<qint64> { element->attributes()->attributeValue(QStringLiteral("objectid")).toLongLong() });
  m_featureLayer->selectFeaturesAsync(query, SelectionMode::New).then(this, [this](FeatureQueryResult* rawFeatureQueryResult)
  {
    onSelectFeaturesCompleted_(rawFeatureQueryResult);
  });

  // set selected feature member
  m_selectedFeature = static_cast<ArcGISFeature*>(element);
  // Don't delete the selected feature when the IdentityResult is deleted.
  m_selectedFeature->setParent(this);
}

void DeleteFeaturesFeatureService::onSelectFeaturesCompleted_(FeatureQueryResult* rawFeatureQueryResult)
{
  // Delete rawFeatureQueryResult pointer when we leave scope.
  auto featureQueryResult = std::unique_ptr<FeatureQueryResult>(rawFeatureQueryResult);

  FeatureIterator iter = featureQueryResult->iterator();
  if (iter.hasNext())
  {
    Feature* feat = iter.next();
    // emit signal for QML
    const QString featureType = feat->attributes()->attributeValue(QStringLiteral("typdamage")).toString();
    // Html tags used to bold and increase pt size of callout title.
    m_mapView->calloutData()->setTitle(QString("<br><b><font size=\"+2\">%1</font></b>").arg(featureType));
    m_mapView->calloutData()->setLocation(feat->geometry().extent().center());
    emit featureSelected();
  }
}

Your browser is no longer supported. Please upgrade your browser for the best experience. See our browser deprecation post for more details.