Register Default Data Connections

• Apr 20, 2021
• 3 minutes to read

You can supply the Web Dashboard with a set of data connections so that users can create new data sources. The predefined data connections are available in the Dashboard Data Source Wizard.

To create a data connection, add a connection string to the configuration file or specify a data connection provider.

Add a Connection String to the Configuration File

To avoid saving the credentials in the dashboard xml file, you can pre-configure the connection string in the application’s configuration file (appsettings.json for ASP.NET Core and Web.config for ASP.NET MVC).

ASP.NET Core:

{
    "ConnectionStrings": {
        "MS SQL Connection": "XpoProvider=MSSqlServer; data source=localhost; initial catalog=Northwind; Integrated Security=SSPI; Persist Security Info=True;",
        "XML Connection": "XpoProvider=InMemoryDataStore;Read Only=true;Data Source=Data\\nwind.xml;",
        "JSON Connection to URI": "uri=https://raw.githubusercontent.com/DevExpress-Examples/DataSources/master/JSON/customers.json"
    }
}

ASP.NET MVC:

<configuration>
    <connectionStrings>
        <add name="MsSqlConnection" connectionString="XpoProvider=MSSqlServer; data source=localhost; initial catalog=Northwind; integrated security=SSPI;" />
        <add name="XmlConnection" connectionString="XpoProvider=InMemoryDataStore;Read Only=true;Data Source=Data\\nwind.xml;" />
        <add name="JsonConnection" connectionString="uri=https://raw.githubusercontent.com/DevExpress-Examples/DataSources/master/JSON/customers.json" />
    </connectionStrings>
</configuration>

Tip

Documentation: Custom Connection Strings for Data Sources

The Web Dashboard control does not pass connection string names to the client. If users create a new data source in the Data Source Wizard, an exception occurs on an attempt to load connection strings. Pass the DashboardConnectionStringsProvider / ConfigFileConnectionStringsProvider instance as the DashboardConfigurator.SetConnectionStringsProvider method’s parameter to allow users to create new data sources based on available connection strings from the configuration file:

ASP.NET Core:

using DevExpress.DashboardWeb;
// ...
public void ConfigureServices(IServiceCollection services) {
    services
        // ...
        .AddDefaultDashboardController(configurator => {
            configurator.SetConnectionStringsProvider(new DashboardConnectionStringsProvider(Configuration));
        });
    // ...
}

ASP.NET MVC:

C#

DashboardConfigurator.SetConnectionStringsProvider.SetConnectionStringsProvider(new DevExpress.DataAccess.Web.ConfigFileConnectionStringsProvider());

VB.NET

DashboardConfigurator.SetConnectionStringsProvider.SetConnectionStringsProvider(New DevExpress.DataAccess.Web.ConfigFileConnectionStringsProvider())

Manage Connection String Access

You can specify connection strings depending on the user’s access rights. Use the DashboardConfigurator.SetConnectionStringsProvider method to specify a data connection provider.

This example shows how to implement a custom provider of connection strings by implementing the IDataSourceWizardConnectionStringsProvider interface.

C#

using DevExpress.DataAccess.ConnectionParameters;
using DevExpress.DataAccess.Web;

// ...

public class MyDataSourceWizardConnectionStringsProvider : IDataSourceWizardConnectionStringsProvider {
    public Dictionary<string, string> GetConnectionDescriptions() {
        Dictionary<string, string> connections = new Dictionary<string, string>();

        // Customize the loaded connections list.  
        connections.Add("jsonUrlConnection", "JSON URL Connection");
        connections.Add("msSqlConnection", "MS SQL Connection");
        return connections;
    }

    public DataConnectionParametersBase GetDataConnectionParameters(string name) {
        // Return custom connection parameters for the custom connection.
        if (name == "jsonUrlConnection") {
            return new JsonSourceConnectionParameters() { 
                JsonSource = new UriJsonSource(
                    new Uri("https://raw.githubusercontent.com/DevExpress-Examples/DataSources/master/JSON/customers.json")) 
                };
        } else if (name == "msSqlConnection") { 
            return new MsSqlConnectionParameters("localhost", "Northwind", "", "", MsSqlAuthorizationType.Windows);
        } 
        throw new System.Exception("The connection string is undefined.");
    }
}

VB.NET

Imports DevExpress.DataAccess.ConnectionParameters
Imports DevExpress.DataAccess.Web

' ...

Public Class MyDataSourceWizardConnectionStringsProvider
    Implements IDataSourceWizardConnectionStringsProvider
    Public Function GetConnectionDescriptions() As Dictionary(Of String, String)
        Dim connections As New Dictionary(Of String, String)()

        ' Customize the loaded connections list.  
        connections.Add("jsonUrlConnection", "JSON URL Connection")
        connections.Add("msSqlConnection", "MS SQL Connection")
        Return connections
    End Function

    Public Function GetDataConnectionParameters(ByVal name As String) As DataConnectionParametersBase
        ' Return custom connection parameters for the custom connection.
        If name = "jsonUrlConnection" Then
            Return New JsonSourceConnectionParameters() With {.JsonSource = New UriJsonSource(New Uri("https://raw.githubusercontent.com/DevExpress-Examples/DataSources/master/JSON/customers.json"))}
        ElseIf name = "msSqlConnection" Then
            Return New MsSqlConnectionParameters("localhost", "Northwind", "", "", MsSqlAuthorizationType.Windows)
        End If
        Throw New System.Exception("The connection string is undefined.")
    End Function
End Class

After you implement a custom connection strings provider, pass this class’s instance to the DashboardConfigurator.SetConnectionStringsProvider method:

ASP.NET Core:

using DevExpress.DashboardWeb;
// ...
public void ConfigureServices(IServiceCollection services) {
    services
        // ...
        .AddDefaultDashboardController(configurator => {
            configurator.SetConnectionStringsProvider(new MyDataSourceWizardConnectionStringsProvider());
        });
    // ...
}

ASP.NET MVC:

C#

using DevExpress.DashboardWeb;
// ...
    public class Global : System.Web.HttpApplication
    {
        protected void Application_Start(object sender, EventArgs e)
        {
            // ...
            DashboardConfigurator.Default.SetConnectionStringsProvider(new MyDataSourceWizardConnectionStringsProvider());
        }
        // ...
    }
}

VB.NET

Imports DevExpress.DashboardWeb
' ...
    Public Class [Global]
        Inherits System.Web.HttpApplication
        Protected Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
            ' ...
            DashboardConfigurator.Default.SetConnectionStringsProvider(New MyDataSourceWizardConnectionStringsProvider())
        End Sub
        ' ...
    End Class
}

Get more information: Manage Multi-Tenancy.