Specify Data Source Settings (JSON)

• Jan 22, 2020
• 3 minutes to read

Select an Existing Data Connection

The “Choose a data connection” page appears if you select JSON on the start page. Select an existing connection from the list.

Tip

See the following topics for information on how to provide a predefined connection:

• ASP.NET Core: Register Default Data Connections
• ASP.NET MVC: Register Default Data Connections
• ASP.NET Web Forms: Register Default Data Connections

Click Next to proceed to the “Select Data Fields” page.

Create a New Data Connection

You can provide end users with the capability to create a new data connection for a JSON Data Source at runtime.

On the server side, implement the IDataSourceWizardConnectionStringsStorage interface to provide an end user with the capability to save the created JSON data connections. Use the created class instance as the ASPxDashboard.SetConnectionStringsProvider / DashboardConfigurator.SetConnectionStringsProvider method’s parameter.

The following code snippet shows how to save the created connection strings in the context of the ASP.NET Core dashboard application.

C#

using DevExpress.DashboardWeb;
using DevExpress.DataAccess.ConnectionParameters;
using System.Collections.Generic;
using System.Linq;

// ...

public void ConfigureServices(IServiceCollection services) {
  services
    .AddMvc()
    .AddDefaultDashboardController((configurator, serviceProvider)  => {
      // Use the ConnectionStringProvider instance as the SetConnectionStringsProvider method's parameter.
      configurator.SetConnectionStringsProvider(new ConnectionStringProvider());
      // ...
    });

  services.AddDevExpressControls();
}
public class ConnectionStringProvider: IDataSourceWizardConnectionStringsStorage {
    readonly Dictionary<string, DataConnectionParametersBase> storage = new Dictionary<string, DataConnectionParametersBase>();
    public Dictionary<string, string> GetConnectionDescriptions() {
      return storage.ToDictionary(p=>p.Key, p=>p.Key);
    }
    public DataConnectionParametersBase GetDataConnectionParameters(string name) {
      return storage[name];
    }
    public void SaveDataConnectionParameters(string name, DataConnectionParametersBase connectionParameters, bool saveCredentials) {
        storage[name] = connectionParameters;
    }
}

VB.NET

Imports DevExpress.DashboardWeb
Imports DevExpress.DataAccess.ConnectionParameters
Imports System.Collections.Generic
Imports System.Linq

' ...

Public Sub ConfigureServices(ByVal services As IServiceCollection)
      ' Use the ConnectionStringProvider instance as the SetConnectionStringsProvider method's parameter.
      ' ...
  services.AddMvc().AddDefaultDashboardController(Function(configurator, serviceProvider) AnonymousMethod1(configurator, serviceProvider))

  services.AddDevExpressControls()
End Sub

Private Function AnonymousMethod1(ByVal configurator As Object, ByVal serviceProvider As Object) As Boolean
    configurator.SetConnectionStringsProvider(New ConnectionStringProvider())
    Return True
End Function
Public Class ConnectionStringProvider
    Implements IDataSourceWizardConnectionStringsStorage
    Private ReadOnly storage As New Dictionary(Of String, DataConnectionParametersBase)()
    Public Function GetConnectionDescriptions() As Dictionary(Of String, String)

        Return storage.ToDictionary(Function(p) p.Key, Function(p) p.Key)
    End Function

    Public Function GetDataConnectionParameters(ByVal name As String) As DataConnectionParametersBase
        Return storage(name)
    End Function

    Public Sub SaveDataConnectionParameters(ByVal name As String, ByVal connectionParameters As DataConnectionParametersBase, ByVal saveCredentials As Boolean)
        storage(name) = connectionParameters
    End Sub
End Class

To enable the capability for end users, set the allowCreateNewJsonConnection property to true:

Platform	API
HTML JavaScript	DataSourceWizardExtensionOptions.allowCreateNewJsonConnection
ASP.NET Core	DataSourceWizardOptionBuilder.AllowCreateNewJsonConnection
MVC	DashboardExtensionSettings.AllowCreateNewJsonConnection
Web Forms	ASPxDashboard.AllowCreateNewJsonConnection

After that, select a new data connection on the “Choose Connection (JSON)” page:

Tip

Example: Web Dashboard - How to create new JSON data sources at runtime

Configure a New Data Connection

On the next page, configure a new data connection:

Specify the connection name and select the JSON source type.

• Web Service Endpoint (URI)

  A URL to a file in the JSON format. You can also specify the Web Service Endpoint’s request parameters (username and password, HTTP headers, or query parameters)

• JSON String

  A string that contains JSON data. You can also use the Upload JSON button to load content from the selected JSON file.

Click Next to proceed to the “Select Data Fields” page.

Select Data Fields

The “Select data fields” page allows you to include / exclude data fields used in a JSON data source.

Click Finish to create a JSON data source.

API

The database wizard pages are identified by the following API:

Page Name	Page ID	Class
Choose Connection (JSON)	JsonDataSourceWizardPageId.ChooseConnectionPage	ChooseJsonConnectionPage
Choose JSON Source	JsonDataSourceWizardPageId.ChooseJsonSourcePage	ChooseJsonSourcePage
Select Data Fields	JsonDataSourceWizardPageId.ChooseJsonSchemaPage	ChooseJsonSchemaPage