Feature collection layer

View inQMLC++
View on GitHub
Sample viewer app

Create a Feature Collection Layer from a Feature Collection Table, and add it to a map.

screenshot

Use case

A Feature Collection allows easily importing external data (such as CSV files), as well as creating custom schema for data that is in non-standardized format. This data can then be used to populate a Feature Collection Table, and displayed in a Feature Collection Layer using the attributes and geometries provided in the external data source. For example, an electricity supplier could use this functionality to visualize existing location data of coverage areas (polygons), power stations (points), transmission lines (polylines), and others.

How to use the sample

When launched, this sample displays a FeatureCollectionLayer with a Point, Polyline and Polygon geometry. Pan and zoom to explore the scene.

How it works

  1. Create a FeatureCollectionLayer using a new feature collection, FeatureCollectionLayer(featureCollection)
  2. Add the feature collection layer to the map, Map::operationalLayers()::append(featureCollectionLayer).
  3. Create a FeatureCollectionTable for the GeometryTypes Point, Polyline, and Polygon, FeatureCollectionTable(fields, geometryType, spatialRefernce)

    • Additionally, pass in a list of Field objects to represent the table's schema. In this case a field of type String named name is added.
  4. Assign a SimpleRenderer to each table to render any Features from that table using the Symbol that was set.
  5. Add the feature collection table to the feature collection, FeatureCollection::tables()::append(featureCollectionTable).
  6. Use the createFeature method to create a feature from the feature collection table, passing an attribute and geometry for that feature, FeatureCollectionTable::createFeature(attributes, geometry).
  7. Add new features to the table, FeatureCollectionTable::addFeature(feature).

Relevant API

  • Feature
  • FeatureCollection
  • FeatureCollectionLayer
  • FeatureCollectionTable
  • Field
  • SimpleRenderer

Tags

collection, feature, layers, table

Sample Code

Feature_Collection_Layer.qmlFeature_Collection_Layer.cppFeature_Collection_Layer.h
                                
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
// [WriteFile Name=Feature_Collection_Layer, Category=Layers]
// [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]

import QtQuick 2.6
import QtQuick.Controls 2.2
import Esri.Samples 1.0

Feature_Collection_LayerSample {
    id: rootRectangle
    clip: true
    width: 800
    height: 600

    // add a mapView component
    MapView {
        anchors.fill: parent
        objectName: "mapView"
    }
}

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