Write to AppSync

Write GPS CO-ordinates back to AWS AppSync

Let’s create a new function to write the lat and long to AWS AppSync, add the following to gps_page.dart within the _GpsSubpageState Class

... // (line 29)
  void _addGPSLocationToDB() async {
    try {
      String graphQLDocument =
          '''mutation CreatePoint(\$lat: String!, \$long: String!) {
              createPoint(input: {lat: \$lat, long: \$long}) {
                id
                lat
                long
              }
        }''';
      var variables = {
        "lat": currentPositionLat.toString(),
        "long": currentPositionLon.toString(),
      };
      var request = GraphQLRequest<String>(
          document: graphQLDocument, variables: variables);
      var operation = Amplify.API.mutate(request: request);
      var response = await operation.response;
      var data = response.data;
      print('Mutation result: ' + data);
    } on ApiException catch (e) {
      print('Mutation failed: $e');
    }
  }

Call the function on button press, add the call below setstate :

..   //  }; closing brace of setstate 
_addGPSLocationToDB();

We’ll need the AWS AppSync endpoint configured in order to write to it, so let’s create that.

amplify add api

Answer the interactive prompts as per below :

? Please select from one of the below mentioned services: GraphQL
? Provide API name: GPS
? Choose the default authorization type for the API API key
? Enter a description for the API key: description
? After how many days from now the API key should expire (1-365): 7
? Do you want to configure advanced settings for the GraphQL API No, I am done.
? Do you have an annotated GraphQL schema? No
? Choose a schema template: Single object with fields (e.g., “Todo” with ID, name, description)
The following types do not have '@auth' enabled. Consider using @auth with @model
         - Todo
Learn more about @auth here: https://docs.amplify.aws/cli/graphql-transformer/auth
GraphQL schema compiled successfully.
Edit your schema at <path>/schema.graphql 
? Do you want to edit the schema now? Yes

The schema file should now be available to edit, modify the file to match below.

type Point @model {
  id: ID!
  lat: String!
  long: String!
}

Ensure the file is saved. The below step uses the newly created schema to create resources configured corectly.

amplify push

Once the AWS resources are fully deployed, the PGS lat and long values will be writen to a DynamoDB table upon pressing the maps button within your Flutter app.

Congratulations, you have finished the workshop!

You can either complete the Optional Lab 5 content, or clean up your AWS resources for the workshop now.

Cleanup

It is recommended to co clean up all the resources created in this workshop once finished to reduce costs.

Delete the AWS Amplify project within the AWS Amplify Console.

amplify delete