IObjectDataSourceValidationService Interface

Allows custom validation of the ObjectDataSource data sources before using them in the document.

Namespace: DevExpress.Snap.Services

Assembly: DevExpress.Snap.v19.2.Core.dll

Declaration

C#

public interface IObjectDataSourceValidationService

VB.NET

Public Interface IObjectDataSourceValidationService

Remarks

The ObjectDataSource can cause an undesired behavior when retrieving its data. This may be unacceptable in certain situations. You can use the SnapControlOptions.DataSourceOptions option to specify whether to prohibit the ObjectDataSource data retrieval, prompt the user or silently load the data. To prompt the user, the default IObjectDataSourceValidationService implementation is called. However, you can implement your own service with a custom IObjectDataSourceValidationService.Validate method to replace the default service.

Example

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-validate-the-objectdatasource-contained-in-the-snap-document-t514281

Form1.cs

            snapControl1.ReplaceService<IObjectDataSourceValidationService>(new MyObjectDataSourceValidationService());
public class MyObjectDataSourceValidationService : IObjectDataSourceValidationService {
    public void Validate(IEnumerable<ObjectDataSource> dataSources) {
        // Do nothing to allow loading.
        // Clear the DataSource and DataMember properties to prohibit loading.
        foreach (ObjectDataSource ds in dataSources) {
            ds.DataSource = null;
            ds.DataMember = null;
        };
    }
}

Form1.vb

            snapControl1.ReplaceService(Of IObjectDataSourceValidationService)(New MyObjectDataSourceValidationService())
Public Class MyObjectDataSourceValidationService
    Implements IObjectDataSourceValidationService

    Public Sub Validate(ByVal dataSources As IEnumerable(Of ObjectDataSource)) Implements IObjectDataSourceValidationService.Validate
        ' Do nothing to allow loading.
        ' Clear the DataSource and DataMember properties to prohibit loading.
        For Each ds As ObjectDataSource In dataSources
            ds.DataSource = Nothing
            ds.DataMember = Nothing
        Next ds
    End Sub
End Class