List related features
List features related to a selected feature.
Use case
Related features are useful for managing relational information, like what you would store in a relational database management system (RDBMS). You can define relationship between records as one-to-one, one-to-many, or many-to-one. For example, you could model inspections and facilities as a many-to-one relationship. Then, for any facility feature, you could list related inspection features.
How to use the sample
Click on a feature to select it. The related features will be displayed in a list.
How it works
- With a
Feature
, callqueryRelatedFeatures
on the feature's feature table. - Iterate over the result's collection of
queryRelatedFeaturesResults
objects to get the related features and add them to a list.
Relevant API
- Feature
- FeatureTable
- FeatureQueryResult
- FeatureTable.queryRelatedFeatures
- RelatedFeatureQueryResult
Tags
features, identify, query, related, relationship, search
Sample Code
ListRelatedFeatures.qml
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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
// [WriteFile Name=ListRelatedFeatures, Category=Features]
// [Legal]
// 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.
// [Legal]
import QtQuick
import QtQuick.Controls
import Esri.ArcGISRuntime
Rectangle {
id: rootRectangle
clip: true
width: 800
height: 600
property FeatureLayer alaskaNationalParks: null
MapView {
id: mapView
anchors.fill: parent
Component.onCompleted: {
// Set the focus on MapView to initially enable keyboard navigation
forceActiveFocus();
}
SelectionProperties {
color: "yellow"
}
// bind the insets to the attribute view so the attribution text shows when the view expands
viewInsets.bottom: attributeView.height
Map {
id: map
initUrl: "https://arcgis.com/home/item.html?id=dcc7466a91294c0ab8f7a094430ab437"
onLoadStatusChanged: {
if (loadStatus !== Enums.LoadStatusLoaded)
return;
// get the Alaska National Parks feature layer
map.operationalLayers.forEach(fl => {
if (fl.name.indexOf("- Alaska National Parks") !== -1) {
alaskaNationalParks = fl;
}
});
}
}
onMouseClicked: mouse => {
// hide the attribute view
attributeView.height = 0;
// clear the list model
relatedFeaturesModel.clear();
// create objects required to do a selection with a query
const clickPoint = mouse.mapPoint;
const mapTolerance = 10 * mapView.unitsPerDIP;
const envelope = ArcGISRuntimeEnvironment.createObject("Envelope", {
xMin: clickPoint.x - mapTolerance,
yMin: clickPoint.y - mapTolerance,
xMax: clickPoint.x + mapTolerance,
yMax: clickPoint.y + mapTolerance,
spatialReference: map.spatialReference
});
const queryParams = ArcGISRuntimeEnvironment.createObject("QueryParameters");
queryParams.geometry = envelope;
queryParams.spatialRelationship = Enums.SpatialRelationshipIntersects;
// clear any selections
alaskaNationalParks.clearSelection();
// select features
alaskaNationalParks.selectFeaturesWithQuery(queryParams, Enums.SelectionModeNew);
}
}
Connections {
target: alaskaNationalParks
function onSelectFeaturesStatusChanged() {
if (alaskaNationalParks.selectFeaturesStatus === Enums.TaskStatusErrored) {
const errorString = "Error: %1".arg(alaskaNationalParks.error.message);
msgDialog.text = errorString;
msgDialog.open();
console.log(errorString);
} else if (alaskaNationalParks.selectFeaturesStatus === Enums.TaskStatusCompleted) {
const featureQueryResult = alaskaNationalParks.selectFeaturesResult;
// iterate over features returned
while (featureQueryResult.iterator.hasNext) {
const arcGISFeature = featureQueryResult.iterator.next();
const selectedTable = arcGISFeature.featureTable;
// connect signal
selectedTable.queryRelatedFeaturesStatusChanged.connect(()=> {
if (selectedTable.queryRelatedFeaturesStatus !== Enums.TaskStatusCompleted)
return;
const relatedFeatureQueryResultList = selectedTable.queryRelatedFeaturesResults;
// iterate over returned RelatedFeatureQueryResults
for (let i = 0; i < relatedFeatureQueryResultList.length; i++) {
// iterate over Features returned
const iter = relatedFeatureQueryResultList[i].iterator;
while (iter.hasNext) {
const feat = iter.next();
const displayFieldName = feat.featureTable.layerInfo.displayFieldName;
const serviceLayerName = feat.featureTable.layerInfo.serviceLayerName;
const displayFieldValue = feat.attributes.attributeValue(displayFieldName);
// add the related feature info to a list model
const listElement = {
"displayFieldName" : displayFieldName,
"displayFieldValue" : displayFieldValue,
"serviceLayerName" : serviceLayerName
};
relatedFeaturesModel.append(listElement);
}
}
// show the attribute view
attributeView.height = 200
});
// zoom to the feature
mapView.setViewpointGeometryAndPadding(arcGISFeature.geometry, 100)
// query related features
selectedTable.queryRelatedFeatures(arcGISFeature);
}
}
}
}
Rectangle {
id: attributeView
anchors {
left: parent.left
right: parent.right
bottom: parent.bottom
}
height: 0
// Animate the expand and collapse of the legend
Behavior on height {
SpringAnimation {
spring: 3
damping: 0.4
}
}
ListView {
anchors {
fill: parent
margins: 5
}
clip: true
model: relatedFeaturesModel
spacing: 5
// Create delegate to display the attributes
delegate: Rectangle {
width: rootRectangle.width
height: childrenRect.height
color: "transparent"
Text {
anchors.horizontalCenter: parent.horizontalCenter
anchors.margins: 10
text: displayFieldValue
font.pixelSize: 12
}
}
// Create a section to separate features by table
section {
property: "serviceLayerName"
criteria: ViewSection.FullString
labelPositioning: ViewSection.CurrentLabelAtStart | ViewSection.InlineLabels
delegate: Rectangle {
width: rootRectangle.width
height: childrenRect.height
color: "lightsteelblue"
Text {
anchors.horizontalCenter: parent.horizontalCenter
text: section
font {
bold: true
pixelSize: 13
}
}
}
}
}
}
ListModel {
id: relatedFeaturesModel
}
Dialog {
id: msgDialog
modal: true
x: Math.round(parent.width - width) / 2
y: Math.round(parent.height - height) / 2
standardButtons: Dialog.Ok
property alias text : textLabel.text
Text {
id: textLabel
text: "Executing geoprocessing failed."
}
}
}