XpoDataStoreProxy.vb

Imports System.Linq
Imports DevExpress.Xpo
Imports DevExpress.Xpo.DB
Imports DevExpress.Xpo.Helpers
Imports DevExpress.Xpo.Metadata
Imports System.Collections.Generic

Namespace WinWebSolution.Module
    Public Class XpoDataStoreProxy
        Implements IDataStore, ICommandChannel

        Private legacyDataLayer As SimpleDataLayer
        Private legacyDataStore As IDataStore
        Private tempDataLayer As SimpleDataLayer
        Private tempDataStore As IDataStore
        Private tempDatabaseTables() As String = {"ModuleInfo", "XPObjectType"}

        Private Function IsTempDatabaseTable(ByVal tableName As String) As Boolean
            If Not String.IsNullOrEmpty(tableName) Then
                For Each currentTableName As String In tempDatabaseTables
                    If tableName.EndsWith(currentTableName) Then
                        Return True
                    End If
                Next currentTableName
            End If
            Return False
        End Function
        Public Sub Initialize(ByVal dictionary As XPDictionary, ByVal legacyConnectionString As String, ByVal tempConnectionString As String)
            Dim legacyDictionary As New ReflectionDictionary()
            Dim tempDictionary As New ReflectionDictionary()
            For Each ci As XPClassInfo In dictionary.Classes
                If Not IsTempDatabaseTable(ci.TableName) Then
                    legacyDictionary.QueryClassInfo(ci.ClassType)
                Else
                    tempDictionary.QueryClassInfo(ci.ClassType)
                End If
            Next ci
            legacyDataStore = XpoDefault.GetConnectionProvider(legacyConnectionString, AutoCreateOption.DatabaseAndSchema)
            legacyDataLayer = New SimpleDataLayer(legacyDictionary, legacyDataStore)

            tempDataStore = XpoDefault.GetConnectionProvider(tempConnectionString, AutoCreateOption.DatabaseAndSchema)
            tempDataLayer = New SimpleDataLayer(tempDictionary, tempDataStore)
        End Sub
        Public ReadOnly Property AutoCreateOption() As AutoCreateOption Implements IDataStore.AutoCreateOption
            Get
                Return AutoCreateOption.DatabaseAndSchema
            End Get
        End Property
        Public Function ModifyData(ByVal ParamArray dmlStatements() As ModificationStatement) As ModificationResult Implements IDataStore.ModifyData
            Dim legacyChanges As New List(Of ModificationStatement)(dmlStatements.Length)
            Dim tempChanges As New List(Of ModificationStatement)(dmlStatements.Length)
            For Each stm As ModificationStatement In dmlStatements
                If IsTempDatabaseTable(stm.Table.Name) Then
                    tempChanges.Add(stm)
                Else
                    legacyChanges.Add(stm)
                End If
            Next stm

            Dim resultSet As New List(Of ParameterValue)()
            If legacyChanges.Count > 0 Then
                resultSet.AddRange(legacyDataLayer.ModifyData(legacyChanges.ToArray()).Identities)
            End If
            If tempChanges.Count > 0 Then
                resultSet.AddRange(tempDataLayer.ModifyData(tempChanges.ToArray()).Identities)
            End If
            Return New ModificationResult(resultSet)
        End Function
        Public Function SelectData(ByVal ParamArray selects() As SelectStatement) As SelectedData Implements IDataStore.SelectData
            Dim isExternals = selects.Select(Function(stmt) IsTempDatabaseTable(stmt.Table.Name)).ToList()
            Dim mainSelects As New List(Of SelectStatement)(selects.Length)
            Dim externalSelects As New List(Of SelectStatement)(selects.Length)
            For i As Integer = 0 To isExternals.Count - 1
                Dim temp = If(isExternals(i), externalSelects, mainSelects)
                temp.Add(selects(i))
            Next i
            Dim externalResults = (If(externalSelects.Count = 0, Enumerable.Empty(Of SelectStatementResult)(), tempDataLayer.SelectData(externalSelects.ToArray()).ResultSet)).GetEnumerator()
            Dim mainResults = (If(mainSelects.Count = 0, Enumerable.Empty(Of SelectStatementResult)(), legacyDataLayer.SelectData(mainSelects.ToArray()).ResultSet)).GetEnumerator()
            Dim results(isExternals.Count - 1) As SelectStatementResult
            For i As Integer = 0 To results.Length - 1
                Dim enumerator = If(isExternals(i), externalResults, mainResults)
                enumerator.MoveNext()
                results(i) = enumerator.Current
            Next i
            Return New SelectedData(results)
        End Function
        Public Function UpdateSchema(ByVal dontCreateIfFirstTableNotExist As Boolean, ByVal ParamArray tables() As DBTable) As UpdateSchemaResult Implements IDataStore.UpdateSchema
            Dim db1Tables As New List(Of DBTable)()
            Dim db2Tables As New List(Of DBTable)()

            For Each table As DBTable In tables
                If Not IsTempDatabaseTable(table.Name) Then
                    db1Tables.Add(table)
                Else
                    db2Tables.Add(table)
                End If
            Next table
            legacyDataStore.UpdateSchema(False, db1Tables.ToArray())
            tempDataStore.UpdateSchema(False, db2Tables.ToArray())
            Return UpdateSchemaResult.SchemaExists
        End Function
        Public Function [Do](ByVal command As String, ByVal args As Object) As Object Implements ICommandChannel.Do
            Return DirectCast(legacyDataLayer, ICommandChannel).Do(command, args)
        End Function
    End Class
End Namespace