Passing XML to the Web Service

This article has been excerpted from book "A Programmer's Guide to ADO.NET in C#".

One more interesting and practical approach to passing an order entry is to pass it using an XML node. SOAP enables you to pass an XML of data. This way the data will have more useful node names such as OrderName rather than a constant representing the order name. You won't have to worry so much about tracking integer constants. Listing 8-7 shows InsertOrderFormNode method for taking an XmlNode with your customer order information. You populate the new DataRow by extracting InnerText from each ChildNode of XmlNode. 

Note: You'll need to include the using System.Xml namespace to utilize XmlNode.

Listing 8-7 web service method populating an order from XML

        [WebMethod(Description = " Insert order from XML")]

        public int InsertOrderFromNode(XmlNode aNode)

        {

            DataSet1 ds = new DataSet1();

            oleDbDataAdapter1.SelectCommand.CommandText =

            "Select * From Orders ORDER BY OredrID";

            oledbDataAdapter1.Fill(ds, "Orders");

            DataRow drLast = ds.Orders.Rows[ds.Orders.Rows.Count - 1];

            int LastOrderID = Convert.ToInt32(drLast["OrderID"]);

            DataSet1.OrdersRow dr = ds.Orders.NewOrdersRow();

            dr.OrderID = LastOrderID + 1;

            dr.OrderDate = Convert.ToDateTime(aNode["OrderDate"].InnerText);

            dr.ShipName = aNode["ShipName"].InnerText;

            dr.ShipAddress = aNode["ShipAddress"].InnerText;

            dr.ShipCity = aNode["ShipCity"].InnerText;

            dr.ShipCountry = aNode["ShipCountry"].InnerText;

            dr.ShipPostalCode = aNode["ShipPostalCode"].InnerText;

            ds.Orders.AddOrdersRow(dr);

            oleDbDataAdapter1.Update(ds, "Orders");

            return dr.OrderID;

        }

Now you add the InsertOrderFromNode method to your existing Web service and test the method as you've been doing in the previous two samples.

Then, on the client side, you use the same client as in the previous sample. You add one more button to the page, so now it looks like figure 8-26.

Figure 8-26. Calling the InsertOrderFromNode Web method

This time, instead of passing an array to your Web service, you can simply pass an XML node with the named nodes of the customer order. You use the XmlDocument class to create the initial node and then populate it with the LoadXml method. The node passes to your new web method, which takes an XmlNode instead of a string array. Listing 8-8 shows how to pass XmlDocument as an input for the InsertorderFromNode method.

Listing 8-8. Client event handler for executing the Web service

        private void Button2_Click(object sender, System.EventArgs e)

        {

            XmlDocument node = new XmlDocument();

            node.LoadXml(

            "<Order>" +

            "<OrderDate>" + TextBox1.Text + "</OrderDate>" +

            "<ShipName >" + TextBox2.Text + "</ShipName>" +

            "<ShipAddress>" + TextBox3.Text + "</ShipAddress >" +

            "<ShipCity>" + TextBox4.Text + "</ShipCity>" +

            "<ShipCountry>" + TextBox5.Text + "</ShipCountry >" +

            "<ShipPostalCode>" + TextBox6.Text + "</ShipPostalCode>" +

            "</Order>");

            mcb.Service1 myWebService = new mcb.Service1();

            myWebService.InsertOrderFromNode(node);

        }

Note: The Web service automatically strips out the root node <#document> when it receives the node, so the root element node on the Web service side is <order>.

Now compile and run application. Insert data to the text boxes and click the InsertOrderFromNode button. To see if program worked, see the orders table of the database.

Conclusion

Hope this article would have helped you in understanding passing XML to the Web Service. See other articles on the website also for further reference.

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