Connect to OpenWeatherMap 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 OpenWeatherMap 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 OpenWeatherMap using standard SQL queries.

Install the CData API Driver for ADO.NET

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

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

Create a OpenWeatherMap-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.
👁 Create a Blazor app project.

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).
👁 Reference ADO.NET for OpenWeatherMap .dll in the Blazor app.

SELECT OpenWeatherMap Data from the Blazor App

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

   Using API Key Authentication

   To obtain an API key, sign up for a free account at https://openweathermap.org/api and navigate to the API keys section of your dashboard. Copy your API key for use in the connection configuration.

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

   • AuthScheme: Set this to APIKey.
   • APIKey: Set this to your OpenWeatherMap API key.

   For example: Profile=C:\path\to\OpenWeatherMap.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your_openweathermap_api_key";

3. The code below creates a simple Blazor app for displaying OpenWeatherMap data, using standard SQL to query OpenWeatherMap 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:\path\to\OpenWeatherMap.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your_openweathermap_api_key";"))
    {
    var sql = "SELECT , FROM AccumulatedPrecipitation WHERE Latitude = '40.7128'";
    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 OpenWeatherMap data as an HTML table in the Blazor app. 👁 Query OpenWeatherMap from Blazor app.
   

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