Create and add features whose attribute values satisfy a predefined set of contingencies.
Use case
Contingent values are a data design feature that allow you to make values in one field dependent on values in another field. Your choice for a value on one field further constrains the domain values that can be placed on another field. In this way, contingent values enforce data integrity by applying additional constraints to reduce the number of valid field inputs.
For example, a field crew working in a sensitive habitat area may be required to stay a certain distance away from occupied bird nests, but the size of that exclusion area differs depending on the bird's level of protection according to presiding laws. Surveyors can add points of bird nests in the work area and their selection of the size of the exclusion area will be contingent on the values in other attribute fields.
How to use the sample
Tap on the map to add a feature symbolizing a bird's nest. Then choose values describing the nest's status, protection, and buffer size. Notice how different values are available depending on the values of preceding fields. Once the contingent values are validated, tap "Save" to add the feature to the map.
How it works
- Create and load a
Geodatabase. - Load the "BirdNests"
GeodatabaseFeatureTable. - Load the
ContingentValuesDefinitionfrom the feature table. - Create a new
FeatureLayerfrom the feature table and add it to the map. - Create a new
Featurefrom the feature table usingFeatureTable.createFeatureWithAttributes - Supply the initial list of selections. This can also be retrieved from the
FeatureTable'sField'sCodedValueDomain - After making the initial selection, retrieve the valid contingent values for each field as you select the values for the attributes.
i. Create a ContingentValuesResult from FeatureTable.contingentValues and pass in the current feature and the target field by name. ii. Get a list of valid ContingentValues from ContingentValuesResult.contingentValuesByFieldGroup with the name of the relevant field group. iii. Loop through the list to create a list of ContingentCodedValue names or the minimum and maximum values of a ContingentRangeValue depending on the type of ContingentValue returned. 8. Validate the new feature's contingent values by creating a list of ContingencyConstrantViolations by passing the new feature to FeatureTable.validateContingencyConstraints. If the list is empty, then it is valid and can be saved to the map.
Relevant API
- ContingencyConstraintViolation
- ContingentCodedValue
- ContingentRangeValue
- ContingentValuesDefinition
- ContingentValuesResult
- Geodatabase
- GeodatabaseFeatureTable
Offline Data
To set up the sample's offline data, see the Use offline data in the samples section of the Qt Samples repository overview.
| Link | Local Location |
|---|---|
| Contingent Values Bird Nests | <userhome>/ArcGIS/Runtime/Data/geodatabase/ContingentValuesBirdNests.geodatabase |
| Fillmore topographic map | <userhome>/ArcGIS/Runtime/Data/vtpk/FillmoreTopographicMap.vtpk |
About the data
The mobile geodatabase contains birds nests in the Fillmore area, defined with contingent values. Each feature contains information about its status, protection, and buffer size.
Additional information
Learn more about contingent values and how to utilize them on the ArcGIS Pro documentation.
Tags
coded values, contingent values, feature table, geodatabase, range values
Sample Code
ContingentValues.qml
// [WriteFile Name=ContingentValues, Category=EditData]
// [Legal]
// Copyright 2022 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 QtQuick.Layouts
import Esri.ArcGISRuntime
import Esri.ArcGISExtras
Rectangle {
id: sampleWindow
clip: true
width: 800
height: 600
readonly property url dataPath: {
Qt.platform.os === "ios" ?
System.writableLocationUrl(System.StandardPathsDocumentsLocation) + "/ArcGIS/Runtime/Data/" :
System.writableLocationUrl(System.StandardPathsHomeLocation) + "/ArcGIS/Runtime/Data/"
}
// Feature to define attributes for with ContingentValues
property var newFeature: null;
// TaskId to track the queryFeatures() function of the GeodatabaseFeatureTable
property var taskId;
// GeodatabaseFeatureTable
property var birdNestsTable: null;
// Field Domains are hardcoded to simplify this sample, but can be obtained from a FeatureTable's Domain
property var statusValues: {"Occupied":"OCCUPIED", "Unoccupied":"UNOCCUPIED"};
property var protectionValues: {"Endangered":"ENDANGERED", "Not endangered":"NOT_ENDANGERED", "N/A":"NA"};
MapView {
id: mapView
anchors.fill: parent
MouseArea {
anchors.fill: parent
visible: attributePrompt.visible
onClicked: mouse => mouse.accepted = !attributePrompt.visible
onWheel: wheel => wheel.accepted = !attributePrompt.visible
}
Component.onCompleted: {
// Set and keep the focus on MapView to enable keyboard navigation
forceActiveFocus();
}
//! [map with basemap from vtpk]
Map {
Basemap {
ArcGISVectorTiledLayer {
url: dataPath + "vtpk/FillmoreTopographicMap.vtpk"
}
}
//... other map properties
//! [map with basemap from vtpk]
ViewpointCenter {
Point {
x: -13236000
y: 4081200
spatialReference: SpatialReference { wkid: 3857 }
}
targetScale: 8822
}
FeatureLayer {
id: nestsLayer
featureTable: birdNestsTable ?? null;
Geodatabase {
id: gdb
path: dataPath + "geodatabase/ContingentValuesBirdNests.geodatabase"
onLoadStatusChanged: {
if (loadStatus === Enums.LoadStatusLoaded) {
birdNestsTable = gdb.geodatabaseFeatureTablesByTableName["BirdNests"];
birdNestsTable.load();
}
}
}
onLoadStatusChanged: {
if (nestsLayer.loadStatus === Enums.LoadStatusLoaded) {
// Load the ContingentValuesDefinition to enable access to the GeodatabaseFeatureTable's ContingentValues data such as FieldGroups and ContingentValuesResults
birdNestsTable.contingentValuesDefinition.load();
// Load map with initial nest buffers showing
bufferFeatures();
}
}
}
}
GraphicsOverlay {
id: bufferGraphicsOverlay
renderer: SimpleRenderer {
SimpleFillSymbol {
style: Enums.SimpleFillSymbolStyleForwardDiagonal
color: "red"
outline: SimpleLineSymbol {
style: Enums.SimpleLineSymbolStyleSolid
color: "black"
width: 2
}
}
}
}
onMouseClicked: mouse => {
// Open attribute prompt and create a new feature for editing
attributePrompt.visible = true;
newFeature = birdNestsTable.createFeatureWithAttributes({}, mouse.mapPoint);
birdNestsTable.addFeature(newFeature);
}
}
Control {
id: attributePrompt
anchors {
top: sampleWindow.top
right: sampleWindow.right
margins: 5
}
background: Rectangle {
color: "#fdfdfd"
}
visible: false
contentItem: Column {
id: inputColumn
spacing: 5
padding: 10
Text {
text: "Status"
font {
bold: true
pointSize: 11
}
}
ComboBox {
id: statusComboBox
// This ComboBox is hardcoded, but can be dynamically obtained from the feature layer's field's domain values
model: ["", "Occupied", "Unoccupied"]
onCurrentValueChanged: {
if (statusComboBox.currentValue === "") {
protectionComboBox.model = [""];
return;
}
// Update the feature's attribute map with the selection
newFeature.attributes.replaceAttribute("Status", statusValues[statusComboBox.currentValue]);
// Append the valid contingent coded values to the subsequent ComboBox
protectionComboBox.model = [""].concat(getContingentValues("Protection", "ProtectionFieldGroup"));
}
}
Text {
text: "Protection"
font {
bold: true
pointSize: 11
}
}
ComboBox {
id: protectionComboBox
model: [""];
enabled: statusComboBox.currentText !== ""
onCurrentValueChanged: {
if (protectionComboBox.currentValue === "")
return;
// Update the feature's attribute map with the selection
newFeature.attributes.replaceAttribute("Protection", protectionValues[protectionComboBox.currentValue]);
// Get the valid contingent range values for the subsequent SpinBox
const minMax = getContingentValues("BufferSize", "BufferSizeFieldGroup")
// If getContingentValues() returned results, update the spin box values
if (minMax[0] !== "") {
rangeValuesSpinBox.from = minMax[0];
rangeValuesSpinBox.to = minMax[1];
// Explicitly set the buffer size to the rangeValuesSpinBox value in case onValueChanged doesn't trigger
newFeature.attributes.replaceAttribute("BufferSize", rangeValuesSpinBox.value);
saveButton.enabled = validateContingentValues();
}
}
}
Text {
text: "Buffer Size"
font {
bold: true
pointSize: 11
}
}
Text {
text: rangeValuesSpinBox.from + " to " + rangeValuesSpinBox.to;
}
SpinBox {
id: rangeValuesSpinBox
editable: true
from: 0;
to: 0;
stepSize: 10
value: 0;
enabled: protectionComboBox.currentText !== ""
onValueChanged: {
if (protectionComboBox.currentValue === "")
return;
newFeature.attributes.replaceAttribute("BufferSize", rangeValuesSpinBox.value);
// Validate that all contingencies are valid, if so, enable the save button
saveButton.enabled = validateContingentValues();
}
}
Button {
id: saveButton
Text {
anchors.fill: parent
horizontalAlignment: Text.AlignHCenter
verticalAlignment: Text.AlignVCenter
text: "Save"
}
enabled: false
onClicked: {
const valid = validateContingentValues();
if (validateContingentValues()) {
birdNestsTable.updateFeature(newFeature);
bufferFeatures();
attributePrompt.visible = false;
}
}
}
Button {
id: discardButton
Text {
anchors.fill: parent
horizontalAlignment: Text.AlignHCenter
verticalAlignment: Text.AlignVCenter
text: "Discard"
}
onClicked: {
birdNestsTable.deleteFeature(newFeature);
attributePrompt.visible = false
}
}
}
onVisibleChanged: {
if (!visible)
return;
// Reset attribute panel values when the panel opens
statusComboBox.currentIndex = 0;
protectionComboBox.currentIndex = 0;
rangeValuesSpinBox.from = 0;
rangeValuesSpinBox.to = 0;
}
}
function getContingentValues(field, fieldGroup) {
const contingentValuesResult = birdNestsTable.contingentValues(newFeature, field);
const contingentValuesList = contingentValuesResult.contingentValuesByFieldGroup[fieldGroup];
const returnList = [];
contingentValuesList.forEach(contingentValue => {
if (contingentValue.objectType === Enums.ContingentValueTypeContingentCodedValue) {
returnList.push(contingentValue.codedValue.name);
} else if (contingentValue.objectType === Enums.ContingentValueTypeContingentRangeValue) {
returnList.push(contingentValue.minValue);
returnList.push(contingentValue.maxValue);
}
});
return returnList;
}
function validateContingentValues() {
const contingencyConstraintsList = birdNestsTable.validateContingencyConstraints(newFeature);
if (contingencyConstraintsList.length === 0)
return true;
return false;
}
QueryParameters {
id: bufferParameters
whereClause: "BufferSize > 0"
}
// This function creates a buffer around nest features based on their BufferSize value
// It is included to demonstrate the sample use case
function bufferFeatures() {
const featureStatusChanged = ()=> {
switch (birdNestsTable.queryFeaturesStatus) {
case Enums.TaskStatusCompleted:
birdNestsTable.queryFeaturesStatusChanged.disconnect(featureStatusChanged);
bufferGraphicsOverlay.graphics.clear();
const result = birdNestsTable.queryFeaturesResults[taskId];
if (result) {
const features = Array.from(result.iterator.features);
features.forEach(feature => {
const buffer = GeometryEngine.buffer(feature.geometry, feature.attributes.attributeValue("BufferSize"));
const bufferGraphic = ArcGISRuntimeEnvironment.createObject("Graphic", {geometry: buffer});
bufferGraphicsOverlay.graphics.append(bufferGraphic);
});
} else {
console.log("The query finished but there was no result for this taskId");
}
break;
case Enums.TaskStatusErrored:
birdNestsTable.queryFeaturesStatusChanged.disconnect(featureStatusChanged);
if (birdNestsTable.error) {
console.log("Feature query error", birdNestsTable.error.message, birdNestsTable.error.additionalMessage);
} else {
console.log("The query encountered an error, but provided no error message");
}
break;
default:
break;
}
}
birdNestsTable.queryFeaturesStatusChanged.connect(featureStatusChanged);
taskId = birdNestsTable.queryFeatures(bufferParameters);
}
}