XmlClient Managed Provider

Shawn Wildermuth

3.50/5 (5 votes)

Apr 17, 2002

73227

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A Class Library that holds a Managed Provider to retreive Load DataSets from Xml sources.

Introduction

This is my first attempt at writing a Managed Provider. The idea behind it was to allow users of the Managed Provider to be able to fill DataSets from XML in a homogeneous way. This way you could mix XML and database data together without having to know exactly which is from which.

Usage Notes

The Connection string for the XmlConnection class takes a URL or File path to an XML file.
The XmlCommand class takes an optional XPath expression to decide which subset of the XML file to include in the DataSet.

Example

    // call using: TestXml(@"c:\test.xml", "descendant::server[name='Kay']", 
    //                      "  ", "File Path with XPath Expression");

    static void TestXml(string URL, string XPath, string indent, string Title)
    {
      Console.WriteLine("Testing {0} \nwith XML Source: {1}", Title, URL);
      XmlDataAdapter da = new XmlDataAdapter(XPath, new XmlConnection(URL));

      da.SelectCommand.Connection.Open();
      DataSet ds = new DataSet();
      
      // Test Filling in with all data
      int rowsAffected = da.Fill(ds);
      Console.WriteLine(indent + "Filled DataSet with {0} rows", rowsAffected);
      string xml = ds.GetXml();

      // Test Filling with Schema only
      DataTable[] aTables = da.FillSchema(ds, SchemaType.Source);
      Console.WriteLine(indent + "Filled DataSet with {0} tables of Schema only", 
                        aTables.GetLength(0));

      // Show XML if XPath is used
      if (XPath != "/") Console.WriteLine(indent + "XPath Results: \n{0}", xml);
    }

Caveats

The DataReader was never implemented.
This Managed Provider is read-only. If you need to write with it, please contact me as I might be able to get something working.
When using an XPath expression in the XmlCommand class, only the first Match is loaded into the DataSet.