Connect to ConstantContact 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 API Driver for ADO.NET can be used with standard ADO.NET interfaces, such as LINQ and Entity Framework, to interact with live ConstantContact 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 ConstantContact using standard SQL queries.

Install the CData API Driver for ADO.NET

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

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

Create a ConstantContact-Connected Blazor App

Start by creating a Blazor project that references the CData API Driver for ADO.NET

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.API.dll, typically located at C:\Program Files\CData\CData API Driver for ADO.NET\lib etstandard2.0).

SELECT ConstantContact Data from the Blazor App

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

   Start by setting the Profile connection property to the location of the ConstantContact Profile on disk (e.g. C:\profiles\ConstantContact.apip). Next, set the ProfileSettings connection property to the connection string for Profile (see below).

   ConstantContact API Profile Settings

   ConstantContact uses OAuth-based authentication.

   First, you will need to register an OAuth application with ConstantContact. You can do so from the ConstantContact API Guide (https://v3.developer.constantcontact.com/api_guide/index.html), under "MyApplications" > "New Application". Your Oauth application will be assigned a client id (API Key) and you can generate a client secret (Secret).

   After setting the following connection properties, you are ready to connect:

   • AuthScheme: Set this to OAuth.
   • InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to manage the process to obtain the OAuthAccessToken.
   • OAuthClientId: Set this to the client_id that is specified in you app settings.
   • OAuthClientSecret: Set this to the client_secret that is specified in you app settings.
   • CallbackURL: Set this to the Redirect URI you specified in your app settings.

   For example: Profile=C:\profiles\ConstantContact.apip;Authscheme=OAuth;OAuthClientId=your_client_id;OAuthClientSecret=your_client_secret;CallbackUrl=your_callback_url;

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

         @page "/"
         @using System.Data;
         @using System.Data.CData.API;
         
         <h1>Hello, world!</h1>
         
         Welcome to your Data app.
         
         <div class="row">
             <div class="col-12">
         
                 @using (APIConnection connection = new APIConnection(
                   "Profile=C:\profiles\ConstantContact.apip;Authscheme=OAuth;OAuthClientId=your_client_id;OAuthClientSecret=your_client_secret;CallbackUrl=your_callback_url;"))
                 {
                     var sql = "SELECT Id, EmailAddress FROM Contacts WHERE CompanyName = 'Acme, Inc.'";
                     var results = new DataTable();
         
                     APIDataAdapter dataAdapter = new APIDataAdapter(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 ConstantContact data as an HTML table in the Blazor app.

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