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How to add geopoints with related data objects

by on February 15, 2015

In another article, we wrote about how to save Backendless data objects with related geopoint(s). The data-to-geo relations are bidirectional. That means that just as a data object can reference a geopoint (or more than one) as a relation, a geopoint may reference a data object or a collection of in its metadata as well.

Consider the example below. The code saves a geopoint which represents the Eiffel Tower. The geopoint references a data object which represents the tower’s main engineer, Gustavo Eiffel, saved in the Architect table. Notice the “gustavoEiffel” object is a plain Java object (a POJO) which is saved in the Data Service storage in Backendless. The relation between the geopoint and the data object is handled through the geopoint’s metadata:

    Architect gustaveEiffel = new Architect();
    gustaveEiffel.setName("Gustave Eiffel");
    
    Calendar calendar = Calendar.getInstance();
    calendar.set(1923, 11, 27);
    gustaveEiffel.setBirthday(calendar.getTime());
    gustaveEiffel.setNationality("French");
    
    Backendless.Data.of(Architect.class).save(gustaveEiffel, new AsyncCallback<Architect>() {
    
       @Override
       public void handleResponse(Architect savedArchitect) {
           GeoPoint eiffelTower = new GeoPoint(48.85815, 2.29452);
           eiffelTower.addCategory("towers");
           eiffelTower.addCategory("placesToVisit");
           eiffelTower.addMetadata("name", "Eiffel Tower");
           eiffelTower.addMetadata("architect", savedArchitect);
    
           Backendless.Geo.savePoint(eiffelTower, new AsyncCallback<GeoPoint>() {
    
               @Override
               public void handleResponse(GeoPoint geoPoint) {
                   Log.i(TAG, "Geo point has been saved - " + geoPoint.getObjectId());
               }
    
               @Override
               public void handleFault(BackendlessFault fault) {
                   Log.i(TAG, fault.getMessage());
               }
           });
       }
    
       @Override
       public void handleFault(BackendlessFault fault) {
           Log.e(TAG, fault.getMessage());
       }
    });

    val gustaveEiffel = Architect()
    gustaveEiffel.name = "Gustave Eiffel"
    
    val calendar = Calendar.getInstance()
    calendar.set(1923, 11, 27)
    gustaveEiffel.birthday = calendar.time
    gustaveEiffel.nationality = "French"
    
    Backendless.Data.of(Architect::class.java).save(gustaveEiffel, object : AsyncCallback<Architect> {
    
       override fun handleResponse(savedArchitect: Architect) {
           val eiffelTower = GeoPoint(48.85815, 2.29452)
           eiffelTower.addCategory("towers")
           eiffelTower.addCategory("placesToVisit")
           eiffelTower.addMetadata("name", "Eiffel Tower")
           eiffelTower.addMetadata("architect", savedArchitect)
    
           Backendless.Geo.savePoint(eiffelTower, object : AsyncCallback<GeoPoint> {
    
               override fun handleResponse(geoPoint: GeoPoint) {
                   Log.i(TAG, "Geo point has been saved - ${geoPoint.objectId}")
               }
    
               override fun handleFault(fault: BackendlessFault) {
                   Log.i(TAG, fault.message)
               }
           })
       }
    
       override fun handleFault(fault: BackendlessFault) {
           Log.e(TAG, fault.message)
       }
    })

    NSString *birthdateString = @"15/12/1832";
    NSDateFormatter *dateFormatter = [NSDateFormatter new];
    dateFormatter.dateFormat = @"dd/MM/yyyy";
        
    Architect *gustaveEiffel = [Architect new];
    gustaveEiffel.name = @"Gustave Eiffel";
    gustaveEiffel.nationality = @"French";
    gustaveEiffel.birthdate = [dateFormatter dateFromString:birthdateString];
        
    [[Backendless.shared.data of:[Architect class]] saveWithEntity:gustaveEiffel responseHandler:^(Architect * savedArchitect) {
        NSDictionary *metadata = @{@"name": @"Eiffel Tower", @"architect": savedArchitect};
        GeoPoint *eiffelTower = [[GeoPoint alloc] initWithLatitude:48.85815 longitude:2.29452 categories:@[@"towers", @"placesToVisit"] metadata:metadata];
        [Backendless.shared.geo saveGeoPointWithGeoPoint:eiffelTower responseHandler:^(GeoPoint *savedPoint) {
            NSLog(@"Geo point has been saved - %@", savedPoint.objectId);
        } errorHandler:^(Fault *fault) {
            NSLog(@"Error: %@", fault.message);
        }];
            
    } errorHandler:^(Fault *fault) {
        NSLog(@"Error: %@", fault.message);
    }];

    let birthdateString = "15/12/1832"
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "dd/MM/yyyy"
            
    let gustaveEiffel = Architect()
    gustaveEiffel.name = "Gustave Eiffel"
    gustaveEiffel.nationality = "French"
    gustaveEiffel.birthdate = dateFormatter.date(from: birthdateString)
            
    Backendless.shared.data.of(Architect.self).save(entity: gustaveEiffel, responseHandler: { savedArchitect in
        let metadata = ["name": "Eiffel Tower", "architect": savedArchitect]
        let eiffelTower = GeoPoint(latitude: 48.85815, longitude: 2.29452, categories: ["towers", "placesToVisit"], metadata: metadata)
        Backendless.shared.geo.saveGeoPoint(geoPoint: eiffelTower, responseHandler: { savedPoint in
            print("Geo point has been saved - \(savedPoint.objectId ?? "")")
        }, errorHandler: { fault in
            print("Error: \(fault.message ?? "")")
        })
    }, errorHandler: { fault in
        print("Error: \(fault.message ?? "")")
    })

    const Backendless = require('backendless')
    /*
     Or use `import Backendless from 'backendless'` for client side.
     If you don't use npm or yarn to install modules, you can add the following line
     <script src="//api.backendless.com/sdk/js/latest/backendless.min.js"></script>
     to your index.html file and use the global Backendless variable.
    */
    
    Backendless.initApp('YOUR_APP_ID', 'YOUR_JS_API_KEY')
    
    const saveArchitect = async () => {
      const architect = new Architect()
    
      architect.setName('Gustave Eiffel')
      architect.setBirthday(new Date('05/12/1980').getTime())
      architect.setNationality('French')
    
      const eiffelTower = new Backendless.GeoPoint()
    
      eiffelTower.latitude = 48.85815
      eiffelTower.longitude = 2.29452
      eiffelTower.categories = ['towers', 'placesToVisit']
      eiffelTower.metadata = {
        name     : 'Eiffel Tower',
        architect: architect
      }
    
      const savedPoint = await Backendless.Geo.savePoint(eiffelTower)
    
      console.log(`Geo point has been saved - ${ savedPoint.objectId }`)
    }
    
    const onError = error => {
      console.error('Server reported an error: ', error.message)
      console.error('error code: ', error.code)
      console.error('http status: ', error.status)
    }
    
    Promise.resolve()
      .then(saveArchitect)
      .catch(onError)
    

    Map gustaveEiffel = {
     "name": "Gustave Eiffel",
     "birthday": DateTime(1923, 11, 27),
     "nationality": "French"
    };
    
    Backendless.Data.of("Architect").save(gustaveEiffel).then((savedArchitect) {
     GeoPoint eiffelTower = GeoPoint.fromLatLng(48.85815, 2.29452);
     eiffelTower.categories = ["towers", "placesToVisit"];
     eiffelTower.metadata = {"name": "Eiffel Tower", "architect": savedArchitect};
    
     Backendless.Geo.savePoint(eiffelTower).then(
       (geoPoint) => print("Geo point has been saved - ${geoPoint.objectId}"));
    });

    The Architect class:

      public class Architect {
         private String nationality;
         private String name;
         private Date birthday;
         private String objectId;
      
         public void setName(String name) {
             this.name = name;
         }
      
         public String getName() {
             return name;
         }
      
         public void setBirthday(Date birthday) {
             this.birthday = birthday;
         }
      
         public Date getBirthday() {
             return birthday;
         }
      
         public void setNationality(String nationality) {
             this.nationality = nationality;
         }
      
         public String getNationality() {
             return nationality;
         }
      
         public String getObjectId() {
             return objectId;
         }
      
         public void setObjectId(String objectId) {
             this.objectId = objectId;
         }
      }

      import java.util.Date
      
      data class Architect(var objectId: String? = null, var birthday: Date? = null,
         var name: String? = null, var nationality: String? = null)

      @interface Architect : NSObject
      
      @property (strong, nonatomic) NSString *name;
      @property (strong, nonatomic) NSString *nationality;
      @property (strong, nonatomic) NSDate *birthdate;
      
      @end

      @objcMembers class Architect: NSObject {
          var name: String?
          var nationality: String?
          var birthdate: Date?
      }

      function Architect() {
        let nationality = ''
        let name = ''
        let birthday
      
        this.___class = 'Architect'
      
        this.setName = function (name) {
          this.name = name
      
          return this
        }
      
        this.getName = function () {
          return this.name
        }
      
        this.setBirthday = function (birthday) {
          this.birthday = birthday
      
          return this
        }
      
        this.getBirthdat = function () {
          return this.birthday
        }
      
        this.setNationality = function (nationality) {
          this.nationality = nationality
      
          return this
        }
      
        this.getNationality = function () {
          return this.nationality
        }
      }

      The Backendless SDK for Flutter uses the map/dictionary-based approach for data persistence.

      Once you run the code and open the Geolocation screen in Backendless Console, you will see the following:

      If you click the Architect object link in the geopoint’s metadata column, the Console displays the following popup which makes it very easy to see the related data object:

      Alternatively, if you navigate to the Data screen and select the Architect table, it will show the saved data object:

      Enjoy!