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Serialize XmlaDataProvider

In this article we will show you how to serialize and deserialize XmlaDataProvider and all of its settings. You can use this feature to save the current state of the provider and load it next time the application is started.

Serialize XmlaDataProvider with DataContractSerializer

We've added the DataContract attribute to all classes used by XmlaDataProvider. So you can easily serialize it by using DataContractSerializer. Below you will find out how to create a serializer and use it with RadPivotGrid.

So lets create a simple class that we'll use to save (when serializing) and load (when deserializing) DataProviderSettings. You have to add the DataContract attribute to the new class and DataMember attribute for its properties.

[DataContract]
public class DataProviderSettings
{
    [DataMember]
    public object[] Aggregates { get; set; }

    [DataMember]
    public object[] Filters { get; set; }

    [DataMember]
    public object[] Rows { get; set; }

    [DataMember]
    public object[] Columns { get; set; }

    [DataMember]
    public int AggregatesLevel { get; set; }

    [DataMember]
    public PivotAxis AggregatesPosition { get; set; }
}
<DataContract> _
Public Class DataProviderSettings
    <DataMember> _
    Public Property Aggregates() As Object()

    <DataMember> _
    Public Property Filters() As Object()

    <DataMember> _
    Public Property Rows() As Object()

    <DataMember> _
    Public Property Columns() As Object()

    <DataMember> _
    Public Property AggregatesLevel() As Integer

    <DataMember> _
    Public Property AggregatesPosition() As PivotAxis
End Class

The next step is to implement the serializer. When serializing the provider, you have to create an instance of DataProviderSettings class and set all of the properties. After that you can serialize the instance to a file or a stream. When using DataContractSerializer you have to give a collection of KnownTypes to the serializer. That's why we've created a new XmlaPivotSerializationHelper class which has a static member - KnownTypes. It consits of all types you'll need in order to serialize XmlaDataProvider. Here's an example how to implement your own serializer:

public abstract class DataProviderSerializer
{
    public abstract IEnumerable<Type> KnownTypes { get; }

    public string Serialize(object context)
    {
        string serialized = string.Empty;

        IDataProvider dataProvider = context as IDataProvider;
        if (dataProvider != null)
        {
            MemoryStream stream = new MemoryStream();

            DataProviderSettings settings = new DataProviderSettings()
            {
                Aggregates = dataProvider.Settings.AggregateDescriptions.OfType<object>().ToArray(),
                Filters = dataProvider.Settings.FilterDescriptions.OfType<object>().ToArray(),
                Rows = dataProvider.Settings.RowGroupDescriptions.OfType<object>().ToArray(),
                Columns = dataProvider.Settings.ColumnGroupDescriptions.OfType<object>().ToArray(),
                AggregatesLevel = dataProvider.Settings.AggregatesLevel,
                AggregatesPosition = dataProvider.Settings.AggregatesPosition
            };

            DataContractSerializer serializer = new DataContractSerializer(typeof(DataProviderSettings), KnownTypes);
            serializer.WriteObject(stream, settings);

            stream.Position = 0;
            var streamReader = new StreamReader(stream);
            serialized += streamReader.ReadToEnd();
        }

        return serialized;
    }

    public void Deserialize(object context, string savedValue)
    {
        IDataProvider dataProvider = context as IDataProvider;
        if (dataProvider != null)
        {
            var stream = new MemoryStream();
            var tw = new StreamWriter(stream);
            tw.Write(savedValue);
            tw.Flush();
            stream.Position = 0;

            DataContractSerializer serializer = new DataContractSerializer(typeof(DataProviderSettings), KnownTypes);
            var result = serializer.ReadObject(stream);

            dataProvider.Settings.AggregateDescriptions.Clear();
            foreach (var aggregateDescription in (result as DataProviderSettings).Aggregates)
            {
                dataProvider.Settings.AggregateDescriptions.Add(aggregateDescription);
            }

            dataProvider.Settings.FilterDescriptions.Clear();
            foreach (var filterDescription in (result as DataProviderSettings).Filters)
            {
                dataProvider.Settings.FilterDescriptions.Add(filterDescription);
            }

            dataProvider.Settings.RowGroupDescriptions.Clear();
            foreach (var rowDescription in (result as DataProviderSettings).Rows)
            {
                dataProvider.Settings.RowGroupDescriptions.Add(rowDescription);
            }

            dataProvider.Settings.ColumnGroupDescriptions.Clear();
            foreach (var columnDescription in (result as DataProviderSettings).Columns)
            {
                dataProvider.Settings.ColumnGroupDescriptions.Add(columnDescription);
            }

            dataProvider.Settings.AggregatesPosition = (result as DataProviderSettings).AggregatesPosition;
            dataProvider.Settings.AggregatesLevel = (result as DataProviderSettings).AggregatesLevel;
        }
    }
}   

public class XmlaProviderSerializer : DataProviderSerializer
{
    public override IEnumerable<Type> KnownTypes
    {
        get
        {
            return XmlaPivotSerializationHelper.KnownTypes;
        }
    }
}
Public MustInherit Class DataProviderSerializer
    Public MustOverride ReadOnly Property KnownTypes() As IEnumerable(Of Type)

    Public Function Serialize(ByVal context As Object) As String
        Dim serialized As String = String.Empty

        Dim dataProvider As IDataProvider = TryCast(context, IDataProvider)
        If dataProvider IsNot Nothing Then
            Dim stream As New MemoryStream()

            Dim settings As New DataProviderSettings() With {.Aggregates = dataProvider.Settings.AggregateDescriptions.OfType(Of Object)().ToArray(), .Filters = dataProvider.Settings.FilterDescriptions.OfType(Of Object)().ToArray(), .Rows = dataProvider.Settings.RowGroupDescriptions.OfType(Of Object)().ToArray(), .Columns = dataProvider.Settings.ColumnGroupDescriptions.OfType(Of Object)().ToArray(), .AggregatesLevel = dataProvider.Settings.AggregatesLevel, .AggregatesPosition = dataProvider.Settings.AggregatesPosition}

            Dim serializer As New DataContractSerializer(GetType(DataProviderSettings), KnownTypes)
            serializer.WriteObject(stream, settings)

            stream.Position = 0
            Dim streamReader = New StreamReader(stream)
            serialized &= streamReader.ReadToEnd()
        End If

        Return serialized
    End Function

    Public Sub Deserialize(ByVal context As Object, ByVal savedValue As String)
        Dim dataProvider As IDataProvider = TryCast(context, IDataProvider)
        If dataProvider IsNot Nothing Then
            Dim stream = New MemoryStream()
            Dim tw = New StreamWriter(stream)
            tw.Write(savedValue)
            tw.Flush()
            stream.Position = 0

            Dim serializer As New DataContractSerializer(GetType(DataProviderSettings), KnownTypes)
            Dim result = serializer.ReadObject(stream)

            dataProvider.Settings.AggregateDescriptions.Clear()
            For Each aggregateDescription In (TryCast(result, DataProviderSettings)).Aggregates
                dataProvider.Settings.AggregateDescriptions.Add(aggregateDescription)
            Next aggregateDescription

            dataProvider.Settings.FilterDescriptions.Clear()
            For Each filterDescription In (TryCast(result, DataProviderSettings)).Filters
                dataProvider.Settings.FilterDescriptions.Add(filterDescription)
            Next filterDescription

            dataProvider.Settings.RowGroupDescriptions.Clear()
            For Each rowDescription In (TryCast(result, DataProviderSettings)).Rows
                dataProvider.Settings.RowGroupDescriptions.Add(rowDescription)
            Next rowDescription

            dataProvider.Settings.ColumnGroupDescriptions.Clear()
            For Each columnDescription In (TryCast(result, DataProviderSettings)).Columns
                dataProvider.Settings.ColumnGroupDescriptions.Add(columnDescription)
            Next columnDescription

            dataProvider.Settings.AggregatesPosition = (TryCast(result, DataProviderSettings)).AggregatesPosition
            dataProvider.Settings.AggregatesLevel = (TryCast(result, DataProviderSettings)).AggregatesLevel
        End If
    End Sub
End Class   

Public Class XmlaProviderSerializer
    Inherits DataProviderSerializer

    Public Overrides ReadOnly Property KnownTypes() As IEnumerable(Of Type)
        Get
            Return XmlaPivotSerializationHelper.KnownTypes
        End Get
    End Property
End Class

So the last step is to serialize the provider and deserialize it:

string lastSerializadProvider;

//serializiation
XmlaProviderSerializer provider = new XmlaProviderSerializer();
this.lastSerializedProvider = provider.Serialize(this.pivot.DataProvider);

//deserialization
XmlaProviderSerializer provider = new XmlaProviderSerializer();
provider.Deserialize(this.pivot.DataProvider, this.lastSerializedProvider);
Dim lastSerializadProvider As String

'serializiation'
Dim provider As New XmlaProviderSerializer()
Me.lastSerializedProvider = provider.Serialize(Me.pivot.DataProvider)

'deserialization'
Dim provider As New XmlaProviderSerializer()
provider.Deserialize(Me.pivot.DataProvider, Me.lastSerializedProvider)

See Also