Query a feature layer (spatial) | OpenLayers

Learn how to perform a spatial query to a feature serviceA feature service is a data service that provides access to spatial and non-spatial data in feature layers, feature layer views, and tables.Learn more.

Make a spatial query to a feature layer using API key authentication

A feature layerA feature layer (server-side) is a spatially-enabled table in a feature service. All features in a feature layer share the same geometry type and set of fields.Learn more can contain a large number of featuresA feature is a single record, also known as a row, that represents a real-world entity. It typically contains a geometry (point, multipoint, polyline, or polygon) and attributes but it can also contain just attributes.Learn more stored in ArcGISArcGIS is the brand name for all of the desktop, server, and developer products and technologies offered by Esri.Learn more. To access a subset of these features, you can execute an SQL or spatial query, either together or individually. The results can contain the attributesAttributes are fields and values for a single feature or non-spatial record. They are typically stored in a database or service such as a feature service.Learn more, geometryA geometry is a geometric shape, such as a point, polyline, or polygon, that contains one or more coordinates and a spatial reference.Learn more, or both for each record. SQL and spatial queries are useful when a feature layer is very large and you want to access only a subset of its data.

In this tutorial, you use the OpenLayers Draw interaction to sketch a featureA feature is a single record, also known as a row, that represents a real-world entity. It typically contains a geometry (point, multipoint, polyline, or polygon) and attributes but it can also contain just attributes.Learn more on the map and ArcGIS REST JS to perform a spatial query against the LA County Parcels hosted feature layerA hosted feature layer is a hosted layer (item) in a portal that is used to manage the properties and settings of a spatially-enabled feature layer in a feature service.Learn more. The layer contains ±2.4 million features. The spatial query returns all of the parcels that intersect the sketched feature. A pop-up is also used to display feature attributes.

Prerequisites

You need an ArcGIS Location Platform or ArcGIS Online account.

Steps

Get the starter app

Select a type of authentication and follow the steps to create a new app.

Choose API key authentication if you:

Want the easiest way to get started.
Want to build public applicationsA public application is an application that allows anonymous access without requiring users to sign in with an ArcGIS account. It supports API key or app authentication.Learn more that access ArcGIS Location ServicesArcGIS Location Services, also referred to as Location Services, are services hosted by Esri that provide geospatial functionality for developing mapping applications. They include the ArcGIS Basemap Styles service, ArcGIS Static Basemap Tiles service, ArcGIS Places service, ArcGIS Geocoding service, ArcGIS Routing service, ArcGIS GeoEnrichment service, and ArcGIS Elevation service. An ArcGIS Location Platform or ArcGIS Online account is required to use the services.Learn more and secure itemsAn item, also known as a content item, is a resource stored in a portal such as a web map, hosted layer, style, script tool, file, or notebook.Learn more.
Have an ArcGIS Location Platform or ArcGIS Online account.

Choose user authentication if you:

Want to build private applications.
Require application users to sign in with their own ArcGIS accountAn ArcGIS account is an identity with a user type and set of privileges that can access specific ArcGIS products, tools, APIs, services, and resources. The main account types that can be used for development are an ArcGIS Location Platform account, ArcGIS Online account, and ArcGIS Enterprise account. ArcGIS Location Platform and ArcGIS Online accounts are also associated with a subscription.Learn more and access resources their behalf.
Have an ArcGIS Online account.

To learn more about both types of authentication, go to Authentication.

You can choose one of the following to create a new CodePen:

Option 1: Complete the Display a map tutorial; or,
Option 2: Start from the Display a map tutorial .

Set up authentication

Create a new API key credentialAPI key credentials are an item that contains the parameters used to create and manage long-lived access tokens for API key authentication. They are a type of developer credential.Learn more with the correct privileges to get an access token.

Go to the Create an API key tutorial and create an API keyAn API key is a long-lived access token created using API key credentials. They are valid for up to one year and are typically embedded directly into client applications.Learn more with the following privilege(s)Privileges are a set of permissions assigned to ArcGIS accounts, developer credentials, and applications that grant access to secure resources and functionality in ArcGIS.Learn more:
- Privileges
  - Location services > Basemaps
- Item access
  - Note: If you are using your own custom data layer for this tutorial, you need to grant the API key credentialsAPI key credentials are an item that contains the parameters used to create and manage long-lived access tokens for API key authentication. They are a type of developer credential.Learn more access to the layer item. Learn more in Item access privileges.

Create a new OAuth credentialOAuth credentials are an item that contains parameters required to implement user authentication or app authentication, including a client_id, client_secret, and redirect URIs. They are a type of developer credential.Learn more to register the application.

Go to the Create OAuth credentials for user authentication tutorial to create an OAuth credential.
Copy the Client ID and Redirect URL from your OAuth credentials item and paste them to a safe location. They will be used in a later step.

Set developer credentials

Use the API key or OAuth developer credentialsDeveloper credentials are a type of item in a portal that contains parameters for authentication. There are two types of developer credentials: API key credentials and OAuth credentials.Learn more so your application can access ArcGIS servicesA service, also known as an ArcGIS service, is software that supports an ArcGIS REST API and provides geospatial functionality or data. A service can be hosted by Esri or in ArcGIS Enterprise.Learn more.

Update the accessToken variable to use your API key.

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    /* Use for API key authentication */
    const accessToken = "YOUR_ACCESS_TOKEN";
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In both the index.html and callback.html files, replace YOUR_CLIENT_ID and YOUR_REDIRECT_URL with the client ID and redirect URL of your OAuth credentialsOAuth credentials are an item that contains parameters required to implement user authentication or app authentication, including a client_id, client_secret, and redirect URIs. They are a type of developer credential.Learn more.

index.html
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    /* Use for user authentication */
    const clientId = "YOUR_CLIENT_ID"; // Your client ID from OAuth credentials
    const redirectUri = ""YOUR_REDIRECT_URI""; // The redirect URL registered in your OAuth credentials
    const session = await arcgisRest.ArcGISIdentityManager.beginOAuth2({
      clientId,
      redirectUri,
      portal: "https://www.arcgis.com/sharing/rest" // Your portal URL
    });

    const accessToken = session.token;

callback.html
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    arcgisRest.ArcGISIdentityManager.completeOAuth2({
      clientId: "YOUR_CLIENT_ID", // Your client ID from OAuth credentials
      redirectUri: "YOUR_REDIRECT_URI", // The redirect URL registered in your OAuth credentials
      portal: "https://www.arcgis.com/sharing/rest" // Your portal URL
    });

Run the app and ensure you can sign in successfully.

If you are unable to sign in, make sure you have the correct redirect URL and port. This URL varies based on your application and typically takes the format of https://<server>[:port]/callback.html or http://my-arcgis-app:/auth. For example, if you are running an application on http://127.0.0.1:5500/, set http://127.0.0.1:5500/callback.html as your redirect URL in the index.html and callback.html file and your developer credential. They all have to match!

Add references

This tutorial uses ArcGIS REST JS to access a feature layerA feature layer (client-side) is a data layer that can access and display features from a feature service that has the same type of geometry and attribute fields.Learn more, and the ol-popup library to display pop-ups.

In the <head> element, add references to the ArcGIS REST JS and ol-popup libraries.

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    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/ol@v10.9.0/ol.css">
    <script src="https://cdn.jsdelivr.net/npm/ol@v10.9.0/dist/ol.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/ol-mapbox-style@13.4.1/dist/olms.js"></script>

    <script src="https://unpkg.com/@esri/arcgis-rest-request@4/dist/bundled/request.umd.js"></script>
    <script
      src="https://unpkg.com/@esri/arcgis-rest-feature-service@4/dist/bundled/feature-service.umd.js"></script>

    <script src="https://unpkg.com/ol-popup@5.1.1/dist/ol-popup.js"></script>
    <link rel="stylesheet" href="https://unpkg.com/ol-popup@5.1.1/src/ol-popup.css">
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Add layers

You will need two Vector layers. interactionLayer will display the query polygon while the user is drawing it. Once the query returns, parcelLayers will display the individual property parcels in the default style. Each contains a Vector source that initially contains no features.

In order to be able to draw shapes, you create a Draw Interaction, connected to your interactionLayer. By setting its type to Polygon, it only allows polygonA polygon is a type of geometry containing an array of rings and a spatial reference. Each ring contains an array of point coordinates, where the first and last point are the same.Learn more featuresA feature is a single record, also known as a row, that represents a real-world entity. It typically contains a geometry (point, multipoint, polyline, or polygon) and attributes but it can also contain just attributes.Learn more to be drawn.

Add a map load handler to the olms initialization. Inside, define Vector layers parcelLayer and interactionLayer. Provide a black Stroke and blue Fill style for parcelLayer. Add each to the map with map.addLayer.

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    olms.apply(map, basemapURL).then(function (map) {

      const parcelLayer = new ol.layer.Vector({
        source: new ol.source.Vector({

        }),
        style: new ol.style.Style({
          stroke: new ol.style.Stroke({
            color: "black"
          }),
          fill: new ol.style.Fill({
            color: "hsl(200,80%,50%)"
          })
        })
      });
      const interactionLayer = new ol.layer.Vector({
        source: new ol.source.Vector()
      });

      map.addLayer(parcelLayer);
      map.addLayer(interactionLayer);
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Add the data attributionData attribution is the requirement to display the names of data source providers in all applications when accessing ArcGIS content, layers, or services.Learn more for the feature layer source.

Go to the LA County Parcels itemAn item, also known as a content item, is a resource stored in a portal such as a web map, hosted layer, style, script tool, file, or notebook.Learn more.
Scroll down to the Acknowledgments section and copy its value.

Paste the copied value to the attributions property.

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    olms.apply(map, basemapURL).then(function (map) {

      const parcelLayer = new ol.layer.Vector({
        source: new ol.source.Vector({

          // Attribution text retrieved from https://arcgis.com/home/item.html?id=a6fdf2ee0e454393a53ba32b9838b303
          attributions: ["| County of Los Angeles Office of the Assessor"]

        }),
        style: new ol.style.Style({
          stroke: new ol.style.Stroke({
            color: "black"
          }),
          fill: new ol.style.Fill({
            color: "hsl(200,80%,50%)"
          })
        })
      });
      const interactionLayer = new ol.layer.Vector({
        source: new ol.source.Vector()
      });

      map.addLayer(parcelLayer);
      map.addLayer(interactionLayer);
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Create a Draw interaction, linked to interactionLayer, and with a type of Polygon. Add it to the map with map.addInteraction.

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      map.addLayer(parcelLayer);
      map.addLayer(interactionLayer);

      const drawInteraction = new ol.interaction.Draw({
        source: interactionLayer.getSource(),
        type: "Polygon",
        stopClick: true // don't fire "click" events (needed later)
      });

      map.addInteraction(drawInteraction);
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In the top right, click Run. You can now click to create multiple polygons.

Execute the query

Use the ArcGIS REST JS queryFeatures method to find features in the LA County Parcels feature layerA feature layer (client-side) is a data layer that can access and display features from a feature service that has the same type of geometry and attribute fields.Learn more that intersect the sketched feature. When the matching parcels are returned, use an EsriJSON feature format to read the featuresA feature is a single record, also known as a row, that represents a real-world entity. It typically contains a geometry (point, multipoint, polyline, or polygon) and attributes but it can also contain just attributes.Learn more and add them to the parcel layer's source.

Create a function called executeQuery with a geometry parameter and then call arcgisRest.queryFeatures.

Pass the geometry. Specify JSON as the return type and specify returnGeometry. All of the featuresA feature is a single record, also known as a row, that represents a real-world entity. It typically contains a geometry (point, multipoint, polyline, or polygon) and attributes but it can also contain just attributes.Learn more within the geometryA geometry is a geometric shape, such as a point, polyline, or polygon, that contains one or more coordinates and a spatial reference.Learn more will be returned.

There are many other spatial relationships that you can specify with spatialRel. For example, you can use esriSpatialRelContains to only return parcels within the sketched polygon. See the ArcGIS services reference for details.

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      map.addInteraction(drawInteraction);

      function executeQuery(geometry) {

        arcgisRest
          .queryFeatures({
            url: "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/LA_County_Parcels/FeatureServer/0",
            geometry: geometry,
            geometryType: "esriGeometryPolygon",
            spatialRel: "esriSpatialRelIntersects",
            f: "json",
            returnGeometry: true
          })

      }
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Add a response handler. Inside, use an EsriJSON feature format to set the returned parcels as the parcel layer's source.

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      function executeQuery(geometry) {

        arcgisRest
          .queryFeatures({
            url: "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/LA_County_Parcels/FeatureServer/0",
            geometry: geometry,
            geometryType: "esriGeometryPolygon",
            spatialRel: "esriSpatialRelIntersects",
            f: "json",
            returnGeometry: true
          })

          .then((response) => {
            const features = new ol.format.EsriJSON().readFeatures(response);
            parcelLayer.getSource().addFeatures(features);
          });

      }
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Trigger the query

When the user completes a polygon, the drawend event is fired, with an object containing the new polygon as a feature attribute. You can use this feature to call executeQuery.

Use the EsriJSON feature format to convert the query polygon into the ArcGIS geometry format. It is not necessary to reproject the data.

Add a handler for the drawEnd event. Inside, use an EsriJSON feature format to convert the feature into an ArcGIS JSON format. Ensure the map's spatial referenceA spatial reference is a set of parameters, typically defined by a WKID, that define the coordinate system and spatial properties for geographic data. Applications use a spatial reference to correctly display the position of geographic data in a map or scene.Learn more information is included, by setting the featureProjection property. Call executeQuery with this feature's geometry.

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      map.addInteraction(drawInteraction);

      drawInteraction.on("drawend", (e) => {
        const feature = new ol.format.EsriJSON().writeFeatureObject(e.feature, {
          featureProjection: map.getView().getProjection()
        });

        executeQuery(feature.geometry);

      });
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At the top right, click Run. When you draw a polygonA polygon is a type of geometry containing an array of rings and a spatial reference. Each ring contains an array of point coordinates, where the first and last point are the same.Learn more, a spatial query will run against the feature layerA feature layer (client-side) is a data layer that can access and display features from a feature service that has the same type of geometry and attribute fields.Learn more and display all land parcels within the boundary of the featureA feature is a single record, also known as a row, that represents a real-world entity. It typically contains a geometry (point, multipoint, polyline, or polygon) and attributes but it can also contain just attributes.Learn more. Interaction polygons and parcels returned from previous queries remain visible. You will address this next.

Add a pop-up

The parcels returned from the query contain many attributes, such as land value and land use type. You can make the parcels interactive by showing a pop-up when the user clicks on a parcel. You create a Popup to display parcel attributes. It is a type of Overlay so you add it to the map with map.addOverlay.

In order for clicking to trigger a pop-up, and not draw another polygon, you need to enable and disable the draw interaction using setActive. Disable the interaction when the user has drawn a complete polygon. Enable it again when the user clicks somewhere other than a parcel, to reset the map. Clear the parcels and interaction layer at the same time.

Create a Popup and save it to a popup variable. Add it to the map with map.addOverlay.

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          .then((response) => {
            const features = new ol.format.EsriJSON().readFeatures(response);
            parcelLayer.getSource().addFeatures(features);
          });

      }

      const popup = new Popup();
      map.addOverlay(popup);
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Create a map click event handler. Inside, use map.getFeaturesAtPixel to get the clicked parcel, if any. If there is one, use popup.show to display a pop-up containing the parcel's APN, use type, land value and taxation city.

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      const popup = new Popup();
      map.addOverlay(popup);

      map.on("click", (event) => {
        let parcel = map.getFeaturesAtPixel(event.pixel, {
          layerFilter: (l) => l === parcelLayer
        })[0];
        if (parcel) {
          // user clicked on a parcel to see more information about it
          const message =
            `<b>Parcel ${parcel.get("APN")}</b>` +
            `<br>Type: ${parcel.get("UseType")} <br>` +
            `Land value: ${parcel.get("Roll_LandValue")} <br>` +
            `Tax Rate City: ${parcel.get("TaxRateCity")}`;

          popup.show(event.coordinate, message);
          drawInteraction.abortDrawing();
        } else {

        }
      });
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If the user did not click a parcel, hide the pop-up with popup.hide. Clear each layer by calling clear on its Source. Use setActive to enabledrawInteraction.

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          popup.show(event.coordinate, message);
          drawInteraction.abortDrawing();
        } else {

          // user clicked elsewhere on the map to reset
          popup.hide();
          parcelLayer.getSource().clear();
          interactionLayer.getSource().clear();
          drawInteraction.setActive(true);
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In the drawend event handler, use setActive to disable drawInteraction.

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      drawInteraction.on("drawend", (e) => {
        const feature = new ol.format.EsriJSON().writeFeatureObject(e.feature, {
          featureProjection: map.getView().getProjection()
        });

        executeQuery(feature.geometry);

        drawInteraction.setActive(false);
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Run the app

Run the app.

When you click on the map to draw a polygon, a spatial query will run against the feature layer and display all land parcels that intersect the boundary of the feature. You can click on a parcel to see a pop-up with information about the parcel, or click somewhere else to reset the map.

What's next?

Learn how to use additional location services in these tutorials:

Map highlighting features returned from a SQL attribute query.

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Execute a SQL query to access polygon features from a feature layer.

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Query demographic information for locations around the world.

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Get local data

Query regional facts and spending trends for a study area in the United States.

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Add a feature layer as GeoJSON

Display and style GeoJSON features from a feature service.

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Style a feature layer

Use data-driven styling to apply symbol colors and styles to feature layers.