Custom Storage Provider

RadPersistenceManager provides the ability for using different providers to store the save state of the controls.

Implementing a Custom Storage Provider

By default RadPersistenceManager store the save state of the controls in an XML file to physical directory within the web application. You may need an alternative mechanism in some scenarios (e.g. saving the state of the control in a Cookie, Database etc.). To create a custom storage provider you need to create a decedent of IStateStorageProvider and implement its methods.

To implement a custom storage provider, you need to:

• Create a class that implements IStateStorageProvider

• Implement SaveStateToStorage and LoadStateFromStorage methods.

using Telerik.Web.UI.PersistenceFramework;

public class CustomStorageProvider : IStateStorageProvider
{
    public void SaveStateToStorage(string key, string serializedState)
    {
        // Save the serialized state somewhere
    }
    public string LoadStateFromStorage(string key)
    {
        return "The saved state";
    }
}

Imports Telerik.Web.UI.PersistenceFramework

Public Class CustomStorageProvider
    Implements Telerik.Web.UI.PersistenceFramework.IStateStorageProvider
    Public Sub SaveStateToStorage(key As String, serializedState As String) Implements IStateStorageProvider.SaveStateToStorage
        ' Save the serialized state somewhere
    End Sub
    Public Function LoadStateFromStorage(key As String) As String Implements IStateStorageProvider.LoadStateFromStorage
        Return "The saved state"
    End Function
End Class

• Set the storage provider used by RadPersistenceManager for storing the serialized control state.

protected void Page_Init(object sender, EventArgs e)
{
    RadPersisterManager1.StorageProvider = new CustomStorageProvider();
}

Protected Sub Page_Init(sender As Object, e As EventArgs) Handles Me.Init
    RadPersisterManager1.StorageProvider = New CustomStorageProvider()
End Sub

The example below demonstrates how to store the state of the RadGrid directly to the database.

<telerik:RadPersistenceManager ID="RadPersistenceManager1" runat="server">
    <PersistenceSettings>
        <telerik:PersistenceSetting ControlID="RadGrid1" />
    </PersistenceSettings>
</telerik:RadPersistenceManager>
<telerik:RadComboBox RenderMode="Lightweight" runat="server" ID="UserSelection" AutoPostBack="true" Width="200px">
    <Items>
        <telerik:RadComboBoxItem Text="User1" Value="1" Selected="true"></telerik:RadComboBoxItem>
        <telerik:RadComboBoxItem Text="User2" Value="2"></telerik:RadComboBoxItem>
        <telerik:RadComboBoxItem Text="User3" Value="3"></telerik:RadComboBoxItem>
    </Items>
</telerik:RadComboBox>
<asp:Button Text="Save settings" ID="SaveSetting" OnClick="SaveSetting_Click" runat="server" />
<asp:Button Text="Load settings" ID="LoadSetting" OnClick="LoadSetting_Click" runat="server" />
<telerik:RadGrid RenderMode="Lightweight" runat="server" ID="RadGrid1" GridLines="None" ShowFooter="True"
    DataSourceID="SqlDataSource1" AllowFilteringByColumn="True" AllowSorting="True"
    ShowGroupPanel="True" AllowPaging="true" PageSize="10">
    <MasterTableView AutoGenerateColumns="False" DataKeyNames="CustomerID" DataSourceID="SqlDataSource1"
        EnableHeaderContextMenu="true">
        <Columns>
            <telerik:GridBoundColumn DataField="CustomerID" DefaultInsertValue="" HeaderText="CustomerID"
                ReadOnly="True" SortExpression="CustomerID" UniqueName="CustomerID">
            </telerik:GridBoundColumn>
            <telerik:GridBoundColumn DataField="CompanyName" DefaultInsertValue="" HeaderText="CompanyName"
                SortExpression="CompanyName" UniqueName="CompanyName">
            </telerik:GridBoundColumn>
            <telerik:GridBoundColumn DataField="ContactName" DefaultInsertValue="" HeaderText="ContactName"
                SortExpression="ContactName" UniqueName="ContactName">
            </telerik:GridBoundColumn>
            <telerik:GridBoundColumn DataField="ContactTitle" DefaultInsertValue="" HeaderText="ContactTitle"
                SortExpression="ContactTitle" UniqueName="ContactTitle">
            </telerik:GridBoundColumn>
            <telerik:GridBoundColumn DataField="City" DefaultInsertValue="" HeaderText="City"
                SortExpression="City" UniqueName="City">
            </telerik:GridBoundColumn>
        </Columns>
    </MasterTableView>
    <ClientSettings AllowDragToGroup="True" AllowColumnsReorder="True">
        <Resizing AllowColumnResize="true"></Resizing>
    </ClientSettings>
</telerik:RadGrid>
<asp:SqlDataSource ID="SqlDataSource1" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
    ProviderName="System.Data.SqlClient" SelectCommand="SELECT [CustomerID], [CompanyName], [ContactName], [ContactTitle], [Address], [City] FROM [Customers]"
    runat="server"></asp:SqlDataSource>

protected void Page_Init(object sender, EventArgs e)
{
    RadPersistenceManager1.StorageProvider = new DBStorageProvider();
}

protected void SaveSetting_Click(object sender, EventArgs e)
{
    string user = UserSelection.SelectedValue;
    RadPersistenceManager1.StorageProviderKey = user;
    RadPersistenceManager1.SaveState();
}
protected void LoadSetting_Click(object sender, EventArgs e)
{
    string user = UserSelection.SelectedValue;
    RadPersistenceManager1.StorageProviderKey = user;
    RadPersistenceManager1.LoadState();
    RadGrid1.Rebind();
}

Protected Sub Page_Init(sender As Object, e As EventArgs) Handles Me.Init
    RadPersistenceManager1.StorageProvider = New DBStorageProvider()
End Sub

Protected Sub SaveSetting_Click(sender As Object, e As EventArgs)
    Dim user As String = UserSelection.SelectedValue
    RadPersistenceManager1.StorageProviderKey = user
    RadPersistenceManager1.SaveState()
End Sub
Protected Sub LoadSetting_Click(sender As Object, e As EventArgs)
    Dim user As String = UserSelection.SelectedValue
    RadPersistenceManager1.StorageProviderKey = user
    RadPersistenceManager1.LoadState()
    RadGrid1.Rebind()
End Sub

using Telerik.Web.UI.PersistenceFramework;

public class DBStorageProvider : IStateStorageProvider
{
    //Declare a global SqlConnection SqlConnection
    SqlConnection SqlConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["UserSettingsConnectionString"].ConnectionString);
    //Declare a global SqlDataAdapter SqlDataAdapter
    public SqlDataAdapter SqlDataAdapter = new SqlDataAdapter();
    //Declare a global SqlCommand SqlCommand
    public SqlCommand SqlCommand = new SqlCommand();

    public void SaveStateToStorage(string key, string serializedState)
    {
        int userID = int.Parse(key);
        string userSettings = serializedState;

        //Open the SqlConnection
        SqlConnection.Open();
        //Update Query to update the Datatable  
        string updateQuery = "UPDATE UserSetting set UserID='" + userID + "',UserSaveSettings='" + userSettings + "'";
        SqlCommand.CommandText = updateQuery;
        SqlCommand.Connection = SqlConnection;
        SqlCommand.ExecuteNonQuery();
        //Close the SqlConnectio
        SqlConnection.Close();
    }
    public string LoadStateFromStorage(string key)
    {

        string selectQuery = "SELECT UserID, UserSaveSettings FROM UserSetting WHERE UserID = '" + key + "'";
        SqlDataAdapter adapter = new SqlDataAdapter();
        adapter.SelectCommand = new SqlCommand(selectQuery, SqlConnection);
        DataTable myDataTable = new DataTable();
        SqlConnection.Open();

        try
        {
            adapter.Fill(myDataTable);
        }
        finally
        {
            SqlConnection.Close();
        }

        return myDataTable.Rows[0]["UserSaveSettings"].ToString();
    }
}

Imports Telerik.Web.UI.PersistenceFramework

Public Class DBStorageProvider
    Implements IStateStorageProvider
    'Declare a global SqlConnection SqlConnection
    Private SqlConnection As New SqlConnection(ConfigurationManager.ConnectionStrings("UserSettingsConnectionString").ConnectionString)
    'Declare a global SqlDataAdapter SqlDataAdapter
    Public SqlDataAdapter As New SqlDataAdapter()
    'Declare a global SqlCommand SqlCommand
    Public SqlCommand As New SqlCommand()

    Public Sub SaveStateToStorage(key As String, serializedState As String) Implements IStateStorageProvider.SaveStateToStorage
        Dim userID As Integer = Integer.Parse(key)
        Dim userSettings As String = serializedState

        'Open the SqlConnection
        SqlConnection.Open()
        'Update Query to update the Datatable  
        Dim updateQuery As String = (Convert.ToString("UPDATE UserSetting set UserID='" + userID + "',UserSaveSettings='") & userSettings) + "'"
        SqlCommand.CommandText = updateQuery
        SqlCommand.Connection = SqlConnection
        SqlCommand.ExecuteNonQuery()
        'Close the SqlConnectio
        SqlConnection.Close()
    End Sub
    Public Function LoadStateFromStorage(key As String) As String Implements IStateStorageProvider.LoadStateFromStorage

        Dim selectQuery As String = (Convert.ToString("SELECT UserID, UserSaveSettings FROM UserSetting WHERE UserID = '") & key) + "'"
        Dim adapter As New SqlDataAdapter()
        adapter.SelectCommand = New SqlCommand(selectQuery, SqlConnection)
        Dim myDataTable As New DataTable()
        SqlConnection.Open()

        Try
            adapter.Fill(myDataTable)
        Finally
            SqlConnection.Close()
        End Try

        Return myDataTable.Rows(0)("UserSaveSettings").ToString()
    End Function
End Class