Extend Your MDK App With a Map Custom Control (Using Metadata Approach)

This step includes creating a mobile project in SAP Build Lobby.

1. In the SAP Build Lobby, click Create > Create to start the creation process.

   

2. Click the Application tile and choose Next.

   

3. Select the Mobile category and choose Next.

   

4. Select the Mobile Application to develop your mobile project in SAP Business Application Studio and choose Next.

   

5. Enter the project name mdk_maps (used for this tutorial) , add a description (optional), and click Review.

   

   SAP Build recommends the dev space it deems most suitable, and it will automatically create a new one for you if you don’t already have one. If you have other dev spaces of the Mobile Application type, you can select between them. If you want to create a different dev space, go to the Dev Space Manager. See Working in the Dev Space Manager.

6. Review the inputs under the Summary tab. If everything looks correct, click Create to proceed with creating your project.

   

7. Your project is being created in the Project table of the lobby. The creation of the project may take a few moments. After the project has been created successfully, click the project to open it.

   

8. The project opens in SAP Business Application Studio.

   

   When you open the SAP Business Application Studio for the first time, a consent window may appear asking for permission to track your usage. Please review and provide your consent accordingly before proceeding.

   

The Storyboard provides a graphical view of the application’s runtime resources, external resources, UI of the application, and the connections between them. This allows for a quick understanding of the application’s structure and components.

• Runtime Resources: In the Runtime Resources section, you can see the mobile services application and mobile destination used in the project, with a dotted-line connected to the External Resources.
• External Resources: In the External Resources section, you can see the external services used in the project, with a dotted-line connection to the Runtime Resource or the UI app.
• UI Application: In the UI Applications section, you can see the mobile applications.

1. Click on + button in the Runtime Resources column to add a mobile services app to your project.

   

   This screen will only show up when your CF login session has expired. Use either Credentials OR SSO Passcode option for authentication. After successful signed in to Cloud Foundry, select your Cloud Foundry Organization and Space where you have set up the initial configuration for your MDK app and click Apply.

   

2. Choose myapp.mdk.demo from the applications list in the Mobile Application Services editor.

   

3. Select com.sap.edm.sampleservice.v4 from the destinations list and click Add App to Project.

   

   You can access the mobile services admin UI by clicking on the Mobile Services option on the right hand side.

   In the storyboard window, the app and mobile destination will be added under the Runtime Resources column. The mobile destination will also be added under the External Resources with a dotted-line connection to the Runtime Resource. The External Resource will be used to create the UI application.

   

4. Click the + button in the UI application column header to add mobile UI for your project.

   

5. In the Basic Information step, provide the below information and click Next. You will modify the generated project in next step and will deploy it later.

   Field	Value
   MDK Template Type	List Detail
   Enable Auto-Deployment to Mobile Services After Project Creation	Select No

   

   The List Detail template generates the offline or online actions, rules, messages and pages to view records. More details on MDK template is available in help documentation.

6. In the Data Collections step, provide the below information and click Finish. Data Collections step retrieves the entity sets information for the selected destination.

   Field	Value
   Enter a path to service (e.g. /sap/opu/odata/sap/SERVICE_NAME)	Leave it as it is
   Select the Service Type	Leave the default value as OData
   Enable Offline	Choose No
   Select all data collections	Leave it as it is
   What types of data will your application contain?	Select Customers (if not selected by default)

   

   Regardless of whether you are creating an online or offline application, this step is needed for app to connect to an OData service. When building an MDK Mobile application, it assumes the OData service created and the destination that points to this service is set up in Mobile Services. For MDK Web application, destination is set up in SAP BTP admin UI.

   Since you have Enable Offline set to Yes, the generated application will be offline enabled in the MDK Mobile client and will run as online in Web environment.

   Data Collections step retrieves the entity sets information for the selected destination.

7. After clicking Finish, the storyboard is updated displaying the UI component. The MDK project is generated in the project explorer based on your selections.

   

The extension control that you will be creating to extend the functionality of your app can be used as base controls by registering it using the MDK editor.

1. Download Map image and save it locally. This image will be used as a display image on the page editor to represent the extension control.

2. Drag & drop map.png file on Images folders.

   

3. Right-click Extensions | select MDK: Register Extension Control.

   

4. In the Template Selection step, select New Metadata Extension Control. Click Next.

   

5. In the Base Information step, provide the below information and click Next.

   Field	Value
   Control Name	mdk_maps
   Module	MyMapModule
   Control	MyMapExtension
   Class	MyMapClass
   Display	click on the link icon and bind it to map.png file

   Here is the basic definition for properties you defined above:

   Module: It is used to identify the extension control. The path to the extension module under <MetadataProject>/Extensions/.

   Control: The name of the file under the <MetadataProject>/Extensions/<Module>/controls that contains the extension class. If not specified, module name would be used as the value for this property.

   Class: The class name of your custom extension class. The client will check for this class at runtime and if it’s found, your extension will be instantiated. Otherwise, a stub with an error message will be shown.

   Display: This property is used for the image to be displayed on the page editor to represent the extension control.

   

6. In the Extension Properties step, fill schema details in Schema column and click Finish.

   JSON Copy

   {
   	"type": "object",
   	"BindType": "",
   	"properties": {
   		"Prop": {
   			"type": "object",
   			"BindType": "",
   			"properties": {
   				"City": {
   					"type": "string",
   					"BindType": ""
   				},
   				"Country": {
   					"type": "string",
   					"BindType": ""
   				},
   				"HouseNumber": {
   					"type": "string",
   					"BindType": ""
   				},
   				"LastName": {
   					"type": "string",
   					"BindType": ""
   				},
   				"PostalCode": {
   					"type": "string",
   					"BindType": ""
   				},
   				"Street": {
   					"type": "string",
   					"BindType": ""
   				}
   			}
   		}
   	}
   }

   Show all 36 lines Show less

   

   Above schema will add these predefined properties (City, Country, HouseNumber, LastName, PostalCode, and Street) in the map extension control which you will bind to Customer entity properties in next step.

   Some additional files and folders are added to the Extensions folder. You will learn more about it in following steps.

   

   You can find more details about registering extension control in this guide.

You will add this registered control in the generated Customers_Detail.page.

1. Navigate to Pages folder | com_sap_edm_sampleservice_v4_Customers | Customers_Detail.page.

2. Remove the body section of the page.

![Remove Page Body Section](https://raw.githubusercontent.com/sap-tutorials/sap-mobile-development-kit/main/tutorials/cp-mobile-dev-kit-map-extension/img-3.1.gif)

3. Expand Section Registered Extension Control, drag & drop the registered mdk_maps control on the page area.

![Map Extension Control Added To Page](https://raw.githubusercontent.com/sap-tutorials/sap-mobile-development-kit/main/tutorials/cp-mobile-dev-kit-map-extension/img-3.2.png)

>You can find more details about the **Section Extension** in [this](https://help.sap.com/doc/3642933ef2e1478fb1578ef2acba4ae9/Latest/en-US/reference/schemadoc/Page/SectionedTable/Container/Extension.schema.html) guide.

4. In the Properties section, set the Height to 600.

![Extension Control Height Set To 600](https://raw.githubusercontent.com/sap-tutorials/sap-mobile-development-kit/main/tutorials/cp-mobile-dev-kit-map-extension/img-3.3.png)  

5. Bind the registered Extension control properties to Customers properties. Under Extension Properties section, expand Prop, click the link icon to open the Object Browser for the City property. Double click the City property of the Customer entity to set it as the binding expression and click OK.

![City Property Binding In Object Browser](https://raw.githubusercontent.com/sap-tutorials/sap-mobile-development-kit/main/tutorials/cp-mobile-dev-kit-map-extension/img-3.4.gif)

Repeat the above step and bind other properties.

![All Extension Properties Bound](https://raw.githubusercontent.com/sap-tutorials/sap-mobile-development-kit/main/tutorials/cp-mobile-dev-kit-map-extension/img-3.5.png)

>Be careful not to bind properties from Address (ESPM.Address).

1. Navigate to Extensions | MyMapModule | controls | MyMapExtension.ts, replace the generated code with the following.

   JavaScript Copy

   import * as app from '@nativescript/core/application';
   import { IControl } from 'mdk-core/controls/IControl';
   import { BaseObservable } from 'mdk-core/observables/BaseObservable';
   import { EventHandler } from 'mdk-core/EventHandler'
   
   export class MyMapClass extends IControl {
       private _observable: BaseObservable;
       private _mapView: any;
       private _geo: any;
       private _gMap: any;
       private _marker: any;
       private _customerInfo = {
           lastName: "",
           houseNumber: "",
           street: "",
           city: "",
           country: "",
           postalCode: "",
           latitiude: "",
           longitude: ""
       }
   
       public initialize(props: any): any {
           super.initialize(props);
   
           //Access the properties passed from Customers_Detail.page to the extension control.
           //in this tutorial, you will be accessing the customer's last name and address
           if (this.definition().data.ExtensionProperties.Prop) {
               var property = this.definition().data.ExtensionProperties.Prop;
               this._customerInfo.lastName = property.LastName;
               this._customerInfo.houseNumber = property.HouseNumber;
               this._customerInfo.street = property.Street;
               this._customerInfo.city = property.City;
               this._customerInfo.country = property.Country;
               this._customerInfo.postalCode = property.PostalCode;
           }
   
           if (app.android) {
               //You will display the Google Maps in a MapView.For more details on Google Maps API for android, visit
               //https://developers.google.com/android/reference/com/google/android/gms/maps/package-summary
   
               this._mapView = new com.google.android.gms.maps.MapView(this.androidContext());
               var localeLanguage = java.util.Locale;
   
               //GeoCoder is required to convert a location to get latitude and longitude
               this._geo = new android.location.Geocoder(this.androidContext(), localeLanguage.ENGLISH);
               this._mapView.onCreate(null);
               this._mapView.onResume();
   
               //when mapview control is used, all the lifecycle activities has to be frowaded to below methods.
               app.android.on(app.AndroidApplication.activityPausedEvent, this.onActivityPaused, this);
               app.android.on(app.AndroidApplication.activityResumedEvent, this.onActivityResumed, this);
               app.android.on(app.AndroidApplication.saveActivityStateEvent, this.onActivitySaveInstanceState, this);
               app.android.on(app.AndroidApplication.activityDestroyedEvent, this.onActivityDestroyed, this);
               var that = this;
   
               //A GoogleMap must be acquired using getMapAsync(OnMapReadyCallback).
               //The MapView automatically initializes the maps system and the view
   
               var mapReadyCallBack = new com.google.android.gms.maps.OnMapReadyCallback({
                   onMapReady: (gMap) => {
                       console.log("inside onMapReady function");
                       that._gMap = gMap;
                       var zoomValue = 6.0;
                       that._gMap.setMinZoomPreference = zoomValue;
                       var customerAddress = that._customerInfo.houseNumber + ' ' + that._customerInfo.street + ' ' + that._customerInfo.city + ' ' +
                           that._customerInfo.country + ' ' + that._customerInfo.postalCode;
                       var data = that._geo.getFromLocationName(customerAddress, 1);
                       var latLng = new com.google.android.gms.maps.model.LatLng(data.get(0).getLatitude(), data.get(0).getLongitude());
                       that._gMap.addMarker(new com.google.android.gms.maps.model.MarkerOptions().position(latLng).title(this._customerInfo.lastName +
                           "'s " + "location"));
                       that._gMap.moveCamera(new com.google.android.gms.maps.CameraUpdateFactory.newLatLng(latLng));
                   }
               });
               this._mapView.getMapAsync(mapReadyCallBack);
           }
   
           if (app.ios) {
   
               /*initiating Apple Maps
               For more details on the Apple Maps visit
               https://developer.apple.com/documentation/mapkit */
               this._mapView = MKMapView.alloc().initWithFrame(CGRectMake(0, 0, 1000, 1000));
           }
       }
   
       private onActivityPaused(args) {
           console.log("onActivityPaused()");
           if (!this._mapView || this != args.activity) return;
           this._mapView.onPause();
       }
   
       private onActivityResumed(args) {
           console.log("onActivityResumed()");
           if (!this._mapView || this != args.activity) return;
           this._mapView.onResume();
       }
   
       private onActivitySaveInstanceState(args) {
           console.log("onActivitySaveInstanceState()");
           if (!this._mapView || this != args.activity) return;
           this._mapView.onSaveInstanceState(args.bundle);
       }
   
       private onActivityDestroyed(args) {
           console.log("onActivityDestroyed()");
           if (!this._mapView || this != args.activity) return;
           this._mapView.onDestroy();
       }
   
       //In case of iOS you'll use CLGeocoder API to convert an address to get latitude and longitude.
       //NOTE - API getlatlang is called only on ios devices
   
       private getlatlang(customerAddress) {
           const that = this;
           return new Promise((resolve, reject) => {
               var latLng = new CLGeocoder();
               latLng.geocodeAddressStringCompletionHandler(customerAddress, function (placemarks, error) {
                   if (error === null && placemarks && placemarks.count > 0) {
                       var pm = placemarks[0];
                       var cordinates = {
                           latitiude: "",
                           longitude: ""
                       }
                       cordinates.latitiude = pm.location.coordinate.latitude;
                       cordinates.longitude = pm.location.coordinate.longitude;
                       resolve(cordinates);
                   } else {
                       reject();
                   }
               });
           });
       }
   
       public view() {
           this.valueResolver().resolveValue([this._customerInfo.houseNumber, this._customerInfo.street, this._customerInfo.city, this._customerInfo
               .country, this._customerInfo.postalCode, this._customerInfo.lastName
           ], this.context)
               .then((address) => {
   
                   this._customerInfo.houseNumber = address[0];
                   this._customerInfo.street = address[1];
                   this._customerInfo.city = address[2];
                   this._customerInfo.country = address[3];
                   this._customerInfo.postalCode = address[4];
                   this._customerInfo.lastName = address[5];
   
                   var customerAddress = address[0] + ' ' + address[1] + ' ' + address[2] + ' ' + address[3] + ' ' + address[4];
                   console.log("customer's address = " + customerAddress);
   
                   if (app.ios) {
                       return this.getlatlang(customerAddress)
                           .then((cordinates) => {
                               /* below code is for the apple maps */
                               var latlong = CLLocationCoordinate2DMake(cordinates.latitiude, cordinates.longitude);
                               var annotation = MKPointAnnotation.alloc().init();
                               annotation.coordinate = latlong;
                               annotation.title = this._customerInfo.lastName + "'s" + " location";
                               this._mapView.centerCoordinate = latlong;
                               this._mapView.addAnnotation(annotation);
                           });
                   }
               });
   
           if (app.android) {
               return this._mapView;
           }
           if (app.ios) {
               return this._mapView;
           }
       }
   
       public viewIsNative() {
           return true;
       }
   
       public observable() {
           if (!this._observable) {
               this._observable = new BaseObservable(this, this.definition(), this.page());
           }
           return this._observable;
       }
   
       public setContainer(container: IControl) {
           // do nothing
       }
   
       public setValue(value: any, notify: boolean, isTextValue?: boolean): Promise<any> {
           // do nothing
           return Promise.resolve();
       }
   }

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   In your import function, if you see errors related to @nativescript/core or mdk-core, you can ignore them. There is currently no reference of such libraries in the MDK editor.

So far, you have learned how to build an MDK application in the SAP Business Application Studio editor. Now, you will Deploy the Project definitions to Mobile Services to use in the Mobile client.

1. Switch to the Customers_Detail.page tab, click the Deploy option in the editor’s header area, and then choose the deployment target as Mobile Services.

   

2. Select deploy target as Mobile Services.

   

   If you want to enable source for debugging the deployed bundle, then choose Yes.

   

   You should see Deploy to Mobile Services successfully! message.

   

Since you will display the customer’s address in Google Maps on Android device, you will need to provide an API key in generated MDK project (step 8).

1. Visit the Google Cloud Platform Console.

2. Click the project drop-down and select or create a new project for which you want to add an API key.

   

3. Click ENABLE APIS AND SERVICES.

   

4. Click Maps SDK for Android.

   

5. Click ENABLE.

   

6. Open Credentials console, click CREATE CREDENTIALS and click API Key.

   

7. Copy this generated key and save it locally. This will be required in step 8.

For iOS, you can just use the App store client. Continue with next step.

For Android, you will pass the API key to the MDK client, there is no way public store client can access it, hence you will create a branded client using MDK SDK or SAP Cloud Build Service.

1. Follow steps 1 to 3 from this tutorial.

2. Create below file structure under DemoSampleApp.mdkproject.

        DemoSampleApp.mdkproject
          ├── App_Resources_Merge
              └── Android
                  ├── app.gradle
                  └── src
                      └── main
                          └── AndroidManifest.xml
   

   

   Files specified in the .mdkproject/App_Resources_Merge folder override a part of the files in <generated-project>/app/App_Resources. You can find more details about it in help documentation.

3. Provide below information in the app.gradle file. Save the changes.

   Java Copy

   dependencies { implementation 'com.google.android.gms:play-services-maps:17.0.0' }

4. Provide below information in the AndroidManifest.xml file. Save the changes.

   XML Copy

   <?xml version="1.0" encoding="utf-8"?>
   <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="__PACKAGE__" xmlns:tools="http://schemas.android.com/tools">
   	<!-- Always include this permission -->
   	<!-- This permission is for "approximate" location data -->
   	<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
   	<!-- Include only if your app benefits from precise location access. -->
   	<!-- This permission is for "precise" location data -->
   	<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
   	<!--
   	Required only when requesting background location access on
   	Android 10 (API level 29) and higher.
   	-->
   	<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
   	<application>
   		<meta-data android:name="com.google.android.geo.API_KEY" android:value="Enter your API Key generated in step 7" />
   	</application>
   </manifest>

5. Create your MDK client either using MDK SDK by following the step 4 from Build Your Mobile Development Kit Client Using MDK SDK tutorial OR using SAP Cloud Build Service by following Build Your mobile development kit Client Using Cloud Build Service tutorial.

Make sure you are choosing the right device platform tab above.