Connect to FHIR Data from Blazor Apps

Blazor is a framework for developing modern, client-side web UIs using .NET technology. Instead of coding in JavaScript, developers can use the familiar C# language and .NET libraries to build app UIs.

The CData ADO.NET Provider for FHIR can be used with standard ADO.NET interfaces, such as LINQ and Entity Framework, to interact with live FHIR data. Since Blazor supports .NET Core, developers can use CData ADO.NET Providers in Blazor apps. In this article, we will guide you to build a simple Blazor app that talks to FHIR using standard SQL queries.

Install the CData ADO.NET Provider for FHIR

CData ADO.NET Providers allow users to access FHIR just like they would access SQL Server, using simple SQL queries.

Install the FHIR ADO.NET Data Provider from the CData website or from NuGet. Search NuGet for "FHIR ADO.NET Data Provider."

Create a FHIR-Connected Blazor App

Start by creating a Blazor project that references the CData ADO.NET Provider for FHIR

1. Create a Blazor project on Visual Studio.
2. From the Solution Explorer, right click Dependencies, then click Add Project Reference.
3. In the Reference Manager, click the Browse button, and choose the .dll file of the installed ADO.NET Provider (e.g. System.Data.CData.FHIR.dll, typically located at C:\Program Files\CData\CData ADO.NET Provider for FHIR\lib etstandard2.0).

SELECT FHIR Data from the Blazor App

1. Open the Index.razor file from the Project page.
2. In a FHIRConnection object, set the connection string:

   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.

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

3. The code below creates a simple Blazor app for displaying FHIR data, using standard SQL to query FHIR just like SQL Server.

         @page "/"
         @using System.Data;
         @using System.Data.CData.FHIR;
         
         <h1>Hello, world!</h1>
         
         Welcome to your Data app.
         
         <div class="row">
             <div class="col-12">
         
                 @using (FHIRConnection connection = new FHIRConnection(
                   "URL=http://test.fhir.org/r4b/;ConnectionType=Generic;ContentType=JSON;AuthScheme=None;"))
                 {
                     var sql = "SELECT Id, [name-use] FROM Patient WHERE [address-city] = 'New York'";
                     var results = new DataTable();
         
                     FHIRDataAdapter dataAdapter = new FHIRDataAdapter(sql, connection);
                     dataAdapter.Fill(results);
         
                     <table class="table table-bordered">
                         <thead class="thead-light">
                             <tr>
                                 @foreach (DataColumn item in results.Rows[0].Table.Columns)
                                 {
                                     <th scope="col">@item.ColumnName</th>
                                 }
                             </tr>
                         </thead>
                         <tbody>
                             @foreach (DataRow row in results.Rows)
                             {
                                 <tr>
                                     @foreach (var column in row.ItemArray)
                                     {
                                         <td>@column.ToString()</td>
                                     }
                                 </tr>
                             }
                         </tbody>
                     </table>
                 }
             </div>
         </div>
       

4. Rebuild and run the project. The ADO.NET Provider renders FHIR data as an HTML table in the Blazor app.

   At this point, you have a FHIR-connected Blazor app, capable of working with live FHIR data just like you would work with a SQL Server instance. Download a free, 30-day trial and start working with live FHIR data in your Blazor apps today.