FileDataLink.cs :  » Persistence-Frameworks » FileHelpers-Library » FileHelpers » DataLink » C# / CSharp Open Source

#region "   Copyright 2005-07 to Marcos Meli - http://www.marcosmeli.com.ar" 

// Errors, suggestions, contributions, send a mail to: marcos@filehelpers.com.

#endregion

using System;
using System.IO;

namespace FileHelpers.DataLink{
  /// <summary>
  /// This class has the responsability to enable the two directional
  /// transformation.
  /// <list type="bullet">
  /// <item> File &lt;-> DataStorage </item>
  /// </list>
  /// </summary>
  /// <remarks>
  /// <para>Uses an <see cref="DataStorage"/> to accomplish this task.</para>
  /// <para>See in the <a href="class_diagram.html">Class Diagram</a> and in the <a href="example_datalink.html">DataLink Sample</a> for more Info.</para>
  /// </remarks>
  /// <seealso href="quick_start.html">Quick Start Guide</seealso>
  /// <seealso href="class_diagram.html">Class Diagram</seealso>
  /// <seealso href="examples.html">Examples of Use</seealso>
  /// <seealso href="example_datalink.html">Example of the DataLink</seealso>
  /// <seealso href="attributes.html">Attributes List</seealso>
  public sealed class FileDataLink
  {
    #region "  Constructor  "

    /// <summary>Create a new instance of the class.</summary>
    /// <param name="provider">The <see cref="DataLink.DataStorage"/> used to performs the transformation.</param>
    public FileDataLink(DataStorage provider)
    {
      mProvider = provider;
      if (mProvider != null)
        mHelperEngine = new FileHelperEngine(mProvider.RecordType);
      else
        throw new ArgumentException("provider cant be null", "provider");
    }

    #endregion

    #region "  HelperEngine  "

    private FileHelperEngine mHelperEngine;

    /// <summary> The internal <see cref="T:FileHelpers.FileHelperEngine"/> used to the file or stream ops. </summary>
    public FileHelperEngine FileHelperEngine
    {
      get { return mHelperEngine; }
    }

    #endregion

    #region "  DataLinkProvider  "

    DataStorage mProvider;

    /// <summary> The internal <see cref="T:FileHelpers.DataLink.IDataLinkProvider"/> used to the link ops. </summary>
    public DataStorage DataStorage
    {
      get { return mProvider; }
    }

    #endregion

    #region "  Last Records "

    private object[] mLastExtractedRecords;

    /// <summary>
    /// An array of the last records extracted from the data source to a file.
    /// </summary>
    public object[] LastExtractedRecords
    {
      get { return mLastExtractedRecords; }
    }

    private object[] mLastInsertedRecords;

    /// <summary>
    /// An array of the last records inserted in the data source that comes from a file.
    /// </summary>
    public object[] LastInsertedRecords
    {
      get { return mLastInsertedRecords; }
    }

    #endregion

    #region "  ExtractTo File/Stream   "

    /// <summary>
    /// Extract records from the data source and insert them to the specified file using the DataLinkProvider <see cref="DataLink.DataStorage.ExtractRecords"/> method.
    /// </summary>
    /// <param name="fileName">The files where the records be written.</param>
    /// <returns>True if the operation is successful. False otherwise.</returns>
    public object[] ExtractToFile(string fileName)
    {
      mLastExtractedRecords = mProvider.ExtractRecords();
      FileHelperEngine.WriteFile(fileName, mLastExtractedRecords);

      return mLastExtractedRecords;
    }

    /// <summary>
    /// Extract records from the data source and insert them to the specified stream using the DataLinkProvider <see cref="DataLink.DataStorage.ExtractRecords"/> method.
    /// </summary>
    /// <param name="writer">The stream where the records be written.</param>
    /// <returns>The extracted records</returns>
    public object[] ExtractToStream(StreamWriter writer)
    {
      mLastExtractedRecords = mProvider.ExtractRecords();
      FileHelperEngine.WriteStream(writer, mLastExtractedRecords);

      return mLastExtractedRecords;
    }

    #endregion

    #region "  InsertFromFile  "

    /// <summary>Extract records from a file and insert them to the data source using the DataLinkProvider <see cref="DataLink.DataStorage.InsertRecords"/> method.</summary>
    /// <param name="fileName">The file with the source records.</param>
    /// <returns>True if the operation is successful. False otherwise.</returns>
    public object[] InsertFromFile(string fileName)
    {
      mLastInsertedRecords = FileHelperEngine.ReadFile(fileName);
      mProvider.InsertRecords(mLastInsertedRecords);

      return mLastInsertedRecords;
    }

    /// <summary>Extract records from a stream and insert them to the data source using the DataLinkProvider <see cref="DataLink.DataStorage.InsertRecords"/> method.</summary>
    /// <param name="reader">The stream with the source records.</param>
    /// <returns>True if the operation is successful. False otherwise.</returns>
    public object[] InsertFromStream(StreamReader reader)
    {
      mLastInsertedRecords = FileHelperEngine.ReadStream(reader);
      mProvider.InsertRecords(mLastInsertedRecords);
      
      return mLastInsertedRecords ;
    }

    #endregion


    /// <summary>The short way to Extract the records from a DataStorage to a file</summary>
    /// <param name="storage">The DataStorage from where get the records</param>
    /// <param name="filename">The file where to write the records to.</param>
    /// <returns>The Extracted records.</returns>
    public static object[] EasyExtractToFile(DataStorage storage, string filename)
    {
      FileDataLink link = new FileDataLink(storage);
      return link.ExtractToFile(filename);
    }

    /// <summary>The short way to Insert Records from a file to a DataStorage</summary>
    /// <param name="storage">The DataStorage where store the records.</param>
    /// <param name="filename">The file with the SourceRecords</param>
    /// <returns>The Inserted records</returns>
    public static object[] EasyInsertFromFile(DataStorage storage, string filename)
    {
      FileDataLink link = new FileDataLink(storage);
      return link.InsertFromFile(filename);
    }

  }
}