Build MVC Applications with Connectivity to FHIR Data

In this article, we will guide you through the process of utilizing wizards within Visual Studio to seamlessly integrate the CData ADO.NET Provider for FHIR into a basic MVC (Model, View, Controller) project.

Create the Entity Framework Model

Follow the steps below to save connection properties and map tables to entities in the data model.

1. Create a new MVC project in Visual Studio. In this example, the project name is MvcFHIRApp.

2. If you are using Entity Framework 6, you will need to take the preliminary step of registering the FHIR Entity Framework provider for your project. See the "LINQ and Entity Framework" chapter in the help documentation for a guide.

   Note that MVC 3 scaffolding and MVC 4 scaffolding do not support Entity Framework 6. You can use your scaffolding with Entity Framework 6 by upgrading to the latest version of MVC.

3. To add the .edmx file from the designer, right-click your Models folder and click Add New Item. Select ADO.NET Entity Data Model, name the model, and click Add. In this example, the name of the model is FHIRModel.
4. In the Entity Data Model wizard, select the option 'EF Designer from database'. The Entity Data Model wizard is displayed.
5. Click New Connection. Select CData FHIR Data Source in the dialog that is displayed.

6. Specify the required connection string properties.

   Set URL to the Service Base URL of the FHIR server. This is the address where the resources are defined in the FHIR server you would like to connect to. Set ConnectionType to a supported connection type. Set ContentType to the format of your documents. Set AuthScheme based on the authentication requirements for your FHIR server.

   Generic, Azure-based, AWS-based, and Google-based FHIR server implementations are supported.

   Sample Service Base URLs

   • Generic: http://my_fhir_server/r4b/
   • Azure: https://MY_AZURE_FHIR.azurehealthcareapis.com/
   • AWS: https://healthlake.REGION.amazonaws.com/datastore/DATASTORE_ID/r4/
   • Google: https://healthcare.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/datasets/DATASET_ID/fhirStores/FHIR_STORE_ID/fhir/

   Generic FHIR Instances

   The product supports connections to custom instances of FHIR. Authentication to custom FHIR servers is handled via OAuth (read more about OAuth in the Help documentation. Before you can connect to custom FHIR instances, you must set ConnectionType to Generic.

   A typical connection string is below:

   URL=http://test.fhir.org/r4b/;ConnectionType=Generic;ContentType=JSON;AuthScheme=None;

7. Name the connection and select whether to include sensitive information, such as connection credentials, in the connection string. For simplicity, this example saves sensitive information in Web.config. The connection settings are saved as FHIREntities.

8. Select the views you need. In this example, Patient is imported. Also, the option to pluralize object names is deselected in this example. Click Finish to create the .edmx file.
9. Build your project to complete this step.

Scaffold the Controller and Views

Once you've established the model and completed the project build, you can employ ASP.NET Scaffolding wizards to generate both the controller and the views.

1. In Solution Explorer, right-click the controllers folder and click Add -> Controller. Select MVC 5 Controller with views, using Entity Framework.
2. In the Add Controller dialog that is then displayed, select the following options:
   • Model class: Select a table you imported; for example, Patient.
   • Data context class: Select your context class.
3. Leave the default values for the other fields.