Add a point, line, and polygon

Learn how to display point, line, and polygon graphics in a map.

You typically use graphics to display geographic data that is not connected to a database and that is not persisted, like highlighting a route between two locations, displaying a search buffer around a selected point, or showing the location of map coordinates entered by the user. Graphics are composed of a geometry, symbol, and attributes.

In this tutorial, you display points, lines, and polygons on a map as graphics.

Prerequisites

Before starting this tutorial, you need the following:

An ArcGIS Location Platform or ArcGIS Online account.
A development and deployment environment that meets the system requirements.
An IDE for Android development in Kotlin.

Develop or download

You have two options for completing this tutorial:

Option 1: Develop the code

Open an Android Studio project

Open the project you created by completing the Display a map tutorial.
Continue with the following instructions to display a point, line, and polygon in the map.
Modify the old project for use in this new tutorial.
1. On your file system, delete the .idea folder, if present, at the top level of your project.
2. In the Android view, open app > res > values > strings.xml.
  
  In the <string name="app_name"> element, change the text content to Add a point, line, and polygon.
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  1 2 3 <resources> <string name="app_name">Add a point, line, and polygon</string> </resources>
3. In the Android view, open Gradle Scripts > settings.gradle.kts.
  
  Change the value of rootProject.name to "Add a point, line, and polygon".
  settings.gradle.kts
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  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 dependencyResolutionManagement { repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS) repositories { google() mavenCentral() maven { url = uri("https://esri.jfrog.io/artifactory/arcgis") } } } rootProject.name = "Add a point, line, and polygon" include(":app")
4. Click File > Sync Project with Gradle files. Android Studio will recognize your changes and create a new .idea folder.

Add import statements

In the Android view, open app > kotlin+java > com.example.app > screens > MainScreen.kt. Replace the import statements with the imports needed for this tutorial.

MainScreen.kt
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@file:OptIn(ExperimentalMaterial3Api::class)  package com.example.app.screens  import androidx.compose.foundation.layout.fillMaxSize import androidx.compose.foundation.layout.padding import androidx.compose.material3.ExperimentalMaterial3Api import androidx.compose.material3.Scaffold import androidx.compose.material3.Text import androidx.compose.material3.TopAppBar import androidx.compose.runtime.Composable import androidx.compose.runtime.remember import androidx.compose.ui.Modifier import androidx.compose.ui.res.stringResource import com.arcgismaps.Color import com.arcgismaps.geometry.Point import com.arcgismaps.geometry.PolygonBuilder import com.arcgismaps.geometry.PolylineBuilder import com.arcgismaps.geometry.SpatialReference import com.arcgismaps.mapping.ArcGISMap import com.arcgismaps.mapping.BasemapStyle import com.arcgismaps.mapping.Viewpoint import com.arcgismaps.mapping.symbology.SimpleFillSymbol import com.arcgismaps.mapping.symbology.SimpleFillSymbolStyle import com.arcgismaps.mapping.symbology.SimpleLineSymbol import com.arcgismaps.mapping.symbology.SimpleLineSymbolStyle import com.arcgismaps.mapping.symbology.SimpleMarkerSymbol import com.arcgismaps.mapping.symbology.SimpleMarkerSymbolStyle import com.arcgismaps.mapping.view.Graphic import com.arcgismaps.mapping.view.GraphicsOverlay import com.arcgismaps.toolkit.geoviewcompose.MapView import com.example.app.R  // Create a blue outline symbol. 

Add a graphics overlay and a list of graphics overlay

You will create a GraphicsOverlay. Then add the graphics overlay to a list named graphicsOverlays.

For information about remembering state between recompositions in Android Jetpack Compose, see State and Jetpack Compose.

In subsequent sections of this tutorial, you will create a point, a line, and a polygon and add each of them to the GraphicsOverlay.

In the MainScreen composable, add a remember block and create a GraphicsOverlay inside it. Then assign remember to a local variable named graphicsOverlay.

MainScreen.kt
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@Composable fun MainScreen() {  // create an ArcGISMap  val map = remember {  createMap()  }   // Create a graphics overlay.  val graphicsOverlay = remember { GraphicsOverlay() }   Scaffold(  topBar = { TopAppBar(title = { Text(text = stringResource(id = R.string.app_name)) }) }  ) {  MapView(  modifier = Modifier.fillMaxSize().padding(it),  arcGISMap = map,   )  } 
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Add a remember block. Inside it, create a list that contains the graphicsOverlay you just created. Then assign remember to a local variable named graphicsOverlays.

MainScreen.kt
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@Composable fun MainScreen() {  // create an ArcGISMap  val map = remember {  createMap()  }   // Create a graphics overlay.  val graphicsOverlay = remember { GraphicsOverlay() }   // Create a list of graphics overlays used by the MapView  val graphicsOverlays = remember { listOf(graphicsOverlay) } 
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Pass graphicsOverlays as the graphicsOverlays argument to MapView.

MainScreen.kt
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 Scaffold(  topBar = { TopAppBar(title = { Text(text = stringResource(id = R.string.app_name)) }) }  ) {  MapView(  modifier = Modifier.fillMaxSize().padding(it),  arcGISMap = map,   graphicsOverlays = graphicsOverlays   )  } 
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Add a point graphic

A point graphic is created using a point and a marker symbol. A point is defined with x and y coordinates, and a spatial reference. For latitude and longitude coordinates, the spatial reference is WGS84.

Create a lazy top-level property named blueOutlineSymbol. In the lazy block, create a solid, blue, 2px-wide SimpleLineSymbol.

MainScreen.kt
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// Create a blue outline symbol. private val blueOutlineSymbol by lazy {  SimpleLineSymbol(SimpleLineSymbolStyle.Solid, Color.fromRgba(0, 0, 255), 2f) } 
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Create a lazy top-level property named pointGraphic.

MainScreen.kt
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private val pointGraphic by lazy {  } 
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In the lazy block of thepointGraphic property , create a Point and a SimpleMarkerSymbol. To create the point, provide x (longitude) and y (latitude) coordinates and a SpatialReference (by calling wgs84() on SpatialReference).

Point graphics support a number of symbol types such as SimpleMarkerSymbol, PictureMarkerSymbol, and TextSymbol. Learn more about symbols at Symbol in the API Reference.

Assign blueOutlineSymbol to the outline property of simpleMarkerSymbol.

MainScreen.kt
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private val pointGraphic by lazy {   // Create a point geometry with a location and spatial reference.  // Point(latitude, longitude, spatial reference)  val point = Point(  x = -118.8065,  y = 34.0005,  spatialReference = SpatialReference.wgs84()  )   // Create a point symbol that is an small red circle and assign the blue outline symbol to its outline property.  val simpleMarkerSymbol = SimpleMarkerSymbol(  style = SimpleMarkerSymbolStyle.Circle,  color = Color.red,  size = 10f  )  simpleMarkerSymbol.outline = blueOutlineSymbol  } 
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Create a Graphic with point and simpleMarkerSymbol.

MainScreen.kt
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private val pointGraphic by lazy {   // Create a point geometry with a location and spatial reference.  // Point(latitude, longitude, spatial reference)  val point = Point(  x = -118.8065,  y = 34.0005,  spatialReference = SpatialReference.wgs84()  )   // Create a point symbol that is an small red circle and assign the blue outline symbol to its outline property.  val simpleMarkerSymbol = SimpleMarkerSymbol(  style = SimpleMarkerSymbolStyle.Circle,  color = Color.red,  size = 10f  )  simpleMarkerSymbol.outline = blueOutlineSymbol   // Create a graphic with the point geometry and symbol.  Graphic(  geometry = point,  symbol = simpleMarkerSymbol  )  } 
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In MainScreen, display the graphic by adding it to the graphics property of graphicsOverlay.

MainScreen.kt
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@Composable fun MainScreen() {  // create an ArcGISMap  val map = remember {  createMap()  }   // Create a graphics overlay.  val graphicsOverlay = remember { GraphicsOverlay() }   // Add the point graphic to the graphics overlay.  graphicsOverlay.graphics.add(pointGraphic)   // Create a list of graphics overlays used by the MapView  val graphicsOverlays = remember { listOf(graphicsOverlay) } 
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Click Run > Run > app to run the app.

In Android Studio, you have two choices for running your app: an actual Android device or the Android Emulator.

Android device

Connect your computer to your Android device, using USB or Wi-Fi. For more details, see How to connect your Android device.

Android Emulator

Create an AVD (Android Virtual Device) to run in the Android Emulator. For details, see Run apps on the Android Emulator.

Selecting a device

When you build and run an app in Android Studio, you must first select a device. From the Android Studio toolbar, you can access the drop-down list of your currently available devices, both virtual and physical.

Drop-down for available devcies in Android Studio .

If you cannot access the list on the toolbar, click Tools > Device Manager.

You should see a point graphic in Point Dume State Beach.

Add a line graphic

A line graphic is created using a polyline and a line symbol. A polyline is defined as a sequence of points.

Polylines have one or more distinct parts. Each part is a sequence of points. For a continuous line, you can use the Polyline constructor to create a polyline with just one part. To create a polyline with more than one part, use a PolylineBuilder.

Create a lazy top-level property named polylineGraphic.

MainScreen.kt
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private val polylineGraphic by lazy {  } 
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In the lazy block, create a Polyline and a SimpleLineSymbol. To create the polyline, create a PolylineBuilder and then call toGeometry() on the polygon builder.

Line graphics support a number of symbol types such as SimpleMarkerSymbol and TextSymbol. Learn more about symbols at Symbol in the API Reference.

MainScreen.kt
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private val polylineGraphic by lazy {   // Create a blue line symbol for the polyline.  val polylineSymbol = SimpleLineSymbol(  style = SimpleLineSymbolStyle.Solid,  color = Color.fromRgba(0, 0, 255),  width = 3f  )   // Create a polylineBuilder with a spatial reference and add three points to it.  val polylineBuilder = PolylineBuilder(SpatialReference.wgs84()) {  addPoint(-118.8215, 34.0139)  addPoint(-118.8148, 34.0080)  addPoint(-118.8088, 34.0016)  }  // then get the polyline from the polyline builder  val polyline = polylineBuilder.toGeometry()  } 
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Create a Graphic with polyline and polylineSymbol.

MainScreen.kt
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private val polylineGraphic by lazy {   // Create a blue line symbol for the polyline.  val polylineSymbol = SimpleLineSymbol(  style = SimpleLineSymbolStyle.Solid,  color = Color.fromRgba(0, 0, 255),  width = 3f  )   // Create a polylineBuilder with a spatial reference and add three points to it.  val polylineBuilder = PolylineBuilder(SpatialReference.wgs84()) {  addPoint(-118.8215, 34.0139)  addPoint(-118.8148, 34.0080)  addPoint(-118.8088, 34.0016)  }  // then get the polyline from the polyline builder  val polyline = polylineBuilder.toGeometry()   // Create a polyline graphic with the polyline geometry and symbol.  Graphic(  geometry = polyline,  symbol = polylineSymbol  )  } 
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In MainScreen, display the graphic by adding it to the graphics property of graphicsOverlay.

MainScreen.kt
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@Composable fun MainScreen() {  // create an ArcGISMap  val map = remember {  createMap()  }   // Create a graphics overlay.  val graphicsOverlay = remember { GraphicsOverlay() }   // Add the point graphic to the graphics overlay.  graphicsOverlay.graphics.add(pointGraphic)   // Add the polyline graphic to the graphics overlay.  graphicsOverlay.graphics.add(polylineGraphic)   // Create a list of graphics overlays used by the MapView  val graphicsOverlays = remember { listOf(graphicsOverlay) } 
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Click Run > Run > app to run the app.

In Android Studio, you have two choices for running your app: an actual Android device or the Android Emulator.

Android device

Connect your computer to your Android device, using USB or Wi-Fi. For more details, see How to connect your Android device.

Android Emulator

Create an AVD (Android Virtual Device) to run in the Android Emulator. For details, see Run apps on the Android Emulator.

Selecting a device

Drop-down for available devcies in Android Studio .

If you cannot access the list on the toolbar, click Tools > Device Manager.

You should see a point and line graphic along Westward Beach.

Add a polygon graphic

A polygon graphic is created using a polygon and a fill symbol. A polygon is defined as a sequence of points that describe a closed boundary.

Polygons have one or more distinct parts. Each part is a sequence of points describing a closed boundary. For a single area with no holes, you can use the Polygon constructor to create a polygon with just one part. To create a polygon with more than one part, use a PolygonBuilder.

Create a lazy top-level property named polygonGraphic.

MainScreen.kt
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private val polygonGraphic by lazy {  } 
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In the lazy block, create a Polygon and a SimpleFillSymbol. To create the polygon, create a PolygonBuilder and then call toGeometry() on the polygon builder.

Polygon graphics support a number of symbol types such as SimpleFillSymbol, PictureFillSymbol, SimpleMarkerSymbol and TextSymbol. Learn more about symbols at Symbol in the API Reference.

Next, create a SimpleFillSymbol that has a solid red fill with an alpha channel of 128 and uses the blueOutlineSymbol defined earlier.

MainScreen.kt
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private val polygonGraphic by lazy {   // Create a polygon builder with a spatial reference and add five vertices (points) to it.  // Then get the polygon from the polygon builder.  val polygonBuilder = PolygonBuilder(SpatialReference.wgs84()) {  addPoint(-118.8189, 34.0137)  addPoint(-118.8067, 34.0215)  addPoint(-118.7914, 34.0163)  addPoint(-118.7959, 34.0085)  addPoint(-118.8085, 34.0035)  }  val polygon = polygonBuilder.toGeometry()   // Create a red fill symbol with an alpha component of 128: values can run from 0 to 255).  val polygonFillSymbol = SimpleFillSymbol(  style = SimpleFillSymbolStyle.Solid,  color = Color.fromRgba(255, 0, 0, 128),  outline = blueOutlineSymbol  )  } 
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Create a Graphic with polygon and polygonFillSymbol.

MainScreen.kt
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private val polygonGraphic by lazy {   // Create a polygon builder with a spatial reference and add five vertices (points) to it.  // Then get the polygon from the polygon builder.  val polygonBuilder = PolygonBuilder(SpatialReference.wgs84()) {  addPoint(-118.8189, 34.0137)  addPoint(-118.8067, 34.0215)  addPoint(-118.7914, 34.0163)  addPoint(-118.7959, 34.0085)  addPoint(-118.8085, 34.0035)  }  val polygon = polygonBuilder.toGeometry()   // Create a red fill symbol with an alpha component of 128: values can run from 0 to 255).  val polygonFillSymbol = SimpleFillSymbol(  style = SimpleFillSymbolStyle.Solid,  color = Color.fromRgba(255, 0, 0, 128),  outline = blueOutlineSymbol  )   // Create a polygon graphic from the polygon geometry and symbol.  Graphic(  geometry = polygon,  symbol = polygonFillSymbol  )  } 
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In MainScreen, display the graphic by adding it to the graphics property of graphicsOverlay.

MainScreen.kt
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@Composable fun MainScreen() {  // create an ArcGISMap  val map = remember {  createMap()  }   // Create a graphics overlay.  val graphicsOverlay = remember { GraphicsOverlay() }   // Add the point graphic to the graphics overlay.  graphicsOverlay.graphics.add(pointGraphic)   // Add the polyline graphic to the graphics overlay.  graphicsOverlay.graphics.add(polylineGraphic)   // Add the polygon graphic to the graphics overlay.  graphicsOverlay.graphics.add(polygonGraphic)   // Create a list of graphics overlays used by the MapView  val graphicsOverlays = remember { listOf(graphicsOverlay) } 
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Click Run > Run > app to run the app.

In Android Studio, you have two choices for running your app: an actual Android device or the Android Emulator.

Android device

Connect your computer to your Android device, using USB or Wi-Fi. For more details, see How to connect your Android device.

Android Emulator

Create an AVD (Android Virtual Device) to run in the Android Emulator. For details, see Run apps on the Android Emulator.

Selecting a device

Drop-down for available devcies in Android Studio .

If you cannot access the list on the toolbar, click Tools > Device Manager.

You should see a point, line, and polygon graphic around Mahou Riviera in the Santa Monica Mountains.

Alternatively, you can download the tutorial solution, as follows.

Option 2: Download the solution

Click the Download solution link in the right-hand side of this page.
Unzip the file to a location on your machine.
Run Android Studio.
Go to File > Open.... Navigate to the solution folder and click Open.

On Windows: If you are in the Welcome to Android Studio dialog, click Open and navigate to the solution folder. Then click Open.

Since the downloaded solution does not contain authentication credentials, you must first set up authentication to create credentials, and then add the developer credentials to the solution.

Set up authentication

To access the secure ArcGIS location services used in this tutorial, you must implement API key authentication or user authentication using an ArcGIS Location Platform or an ArcGIS Online account.

You can implement API key authentication or user authentication in this tutorial. Compare the differences below:

API key authentication

Users are not required to sign in.
Requires creating an API key credential with the correct privileges.
API keys are long-lived access tokens.
Service usage is billed to the API key owner/developer.
Simplest authentication method to implement.
Recommended approach for new ArcGIS developers.

Learn more in API key authentication.

User authentication

Users are required to sign in with an ArcGIS account.
User accounts must have privilege to access the ArcGIS services used in application.
Requires creating OAuth credentials.
Application uses a redirect URL and client ID.
Service usage is billed to the organization of the user signed into the application.

Learn more in User authentication.

Create a new API key access token with privileges to access the secure resources used in this tutorial.

Complete the Create an API key tutorial and create an API key with the following privilege(s):
- Privileges
  - Location services > Basemaps
Copy and paste the API key access token into a safe location. It will be used in a later step.

Create new OAuth credentials to access the secure resources used in this tutorial.

Complete the Create OAuth credentials for user authentication tutorial to obtain a Client ID and Redirect URL.

A Client ID uniquely identifies your app on the authenticating server. If the server cannot find an app with the provided Client ID, it will not proceed with authentication.
The Redirect URL (also referred to as a callback url) is used to identify a response from the authenticating server when the system returns control back to your app after an OAuth login. Since it does not necessarily represent a valid endpoint that a user could navigate to, the redirect URL can use a custom scheme, such as my-app://auth. It is important to make sure the redirect URL used in your app's code matches a redirect URL configured on the authenticating server.
Copy and paste the Client ID and Redirect URL into a safe location. They will be used in a later step.

All users that access this application need account privileges to access the ArcGIS Basemap Styles service.

Set developer credentials in the solution

To allow your app users to access ArcGIS location services, use the developer credentials that you created in the Set up authentication step to authenticate requests for resources.

In the Android view of Android Studio, open app > kotlin+java > com.example.app > MainActivity. Set the AuthenticationMode to .API_KEY.

MainActivity.kt
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class MainActivity : ComponentActivity() {   private enum class AuthenticationMode { API_KEY, USER_AUTH }   private val authenticationMode = AuthenticationMode.API_KEY 
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Set the apiKey property with your API key access token.

MainActivity.kt
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 override fun onCreate(savedInstanceState: Bundle?) {  super.onCreate(savedInstanceState)   when (authenticationMode) {  AuthenticationMode.API_KEY -> {   ArcGISEnvironment.apiKey = ApiKey.create("YOUR_ACCESS_TOKEN")   } 
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Best Practice: The access token is stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

In the Android view of Android Studio, open app > kotlin+java > com.example.app > MainActivity. Set the AuthenticationMode to .USER_AUTH.

MainActivity.kt
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class MainActivity : ComponentActivity() {  private enum class AuthenticationMode { API_KEY, USER_AUTH }   private val authenticationMode = AuthenticationMode.USER_AUTH

Set your clientID and redirectURL values. You must use the RedirectURL that you supplied for your app in the user authentication part of the Set up authentication step.

MainActivity.kt
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 AuthenticationMode.USER_AUTH -> {  authenticatorState.oAuthUserConfigurations = listOf(  OAuthUserConfiguration(  portalUrl = "https://www.arcgis.com",   clientId = "YOUR_CLIENT_ID",  redirectUrl = "YOUR_REDIRECT_URL"   )  ) 

Open app > manifests > AndroidManifest.xml.
Set the android:scheme and android:host using the scheme and host from your RedirectURL.

A redirectURL is composed of a scheme and a host component. The format for the redirect url is scheme://host. For example, if the redirect url is myscheme://myhost then the scheme is myscheme and the host is myhost.
AndroidManifest.xml
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```
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  <data  android:scheme="your_redirect_url_scheme"  android:host="your_redirect_url_host" /> 
```
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Best Practice: The OAuth credentials are stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

Run the app

Click Run > Run > app to run the app.

You should see a point, line, and polygon graphic around Mahou Riviera in the Santa Monica Mountains.

What's next

Learn how to use additional API features, ArcGIS location services, and ArcGIS tools in these tutorials: