Development form page 388

kiwibrit · September 22nd, 2009, 04:11 PM

Hope it's OK to ask this here. I want to develop a web page similar to page Genres.aspx - but using a web service to get an xml file from another server, instead of SQL tables from a local one. For testing, I have the web service on line at another web site (call it website2) - in practice it will be on a server at work.

Rather than coming from SQL tables, the data will come from an xml file on website2. I have found that I can create a the web service - and access it and hence the xml file via a dataset - but my coding is getting messy - moreover, so far I have been able only to read and edit the data - but not update the file itself. I had thought what I am trying to do would be a fairly simple extension of what I had done in the book - but that's not been so. Nevertheless, I have gone back to the book example to try and re-start.

Two questions:

1. Up until now, I have bound the grid view to the dataset in the code-behind - but have not seen away to show that as the data source in the GridView smart tag - may be because the datasource does not lead to full Gridview functionality. Could you suggest a better way of declaring the data set - and also comment on how the dataset and web method could allow writing as well as reading?

Web method

Code:

Imports System.Web
Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports System.Xml
<System.Web.Script.Services.ScriptService()> _
<WebService(Namespace:="http://example.com/")> _
<WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Public Class transxml
    Inherits System.Web.Services.WebService

    <WebMethod()> Public Function GetXmlFile() As XmlNode
        Dim doc As New XmlDocument()
        doc.Load(Server.MapPath("Tester/test.xml"))
        Return doc.DocumentElement
    End Function
End Class

Datasorce declaration

Code:

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim ws As New BooksInfo.transxml()
        Dim element As XmlElement = DirectCast(ws.GetXmlFile(), XmlElement)
        Dim ds As New DataSet()
        Dim xnr As New XmlNodeReader(element)
        ds.ReadXml(xnr)

        GridView1.DataSource = ds
        GridView1.DataBind()

    End Sub

[code]

Question 2.

When I do get the dataset sorted out - looking at the Genres.aspx example for reference - would it be sensible to replace

Code:

            <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:PlanetWroxConnectionString1 %>" DeleteCommand="DELETE FROM [Genre] WHERE [Id] = @Id" InsertCommand="INSERT INTO [Genre] ([Name], [SortOrder]) VALUES (@Name, @SortOrder)" ProviderName="<%$ ConnectionStrings:PlanetWroxConnectionString1.ProviderName %>" SelectCommand="SELECT [Id], [Name], [SortOrder] FROM [Genre]" UpdateCommand="UPDATE [Genre] SET [Name] = @Name, [SortOrder] = @SortOrder WHERE [Id] = @Id">

with an XMLDataSource expression?

Imar · September 23rd, 2009, 07:35 AM

Quote:

on how the dataset and web method could allow writing as well as reading?

For this to work, you need to create a web service method that allows updates.

The SqlDataSource (and many other DataSource controls) are designed to be read/write. In your case, you need to recreate this behavior if you want to do this through web services. Selecting data from an XML file is easy as you found out, but you need more work to update the file again. You may find this useful: http://aspnet.4guysfromrolla.com/articles/112603-1.aspx

It's a bit dated article, but it shows the general principle.

To learn more about editing XML with the XmlDataSource, take a look here: http://msdn.microsoft.com/en-us/libr...atasource.aspx

Hope this helps,

Imar

kiwibrit · September 23rd, 2009, 09:58 AM

Thanks Imar - very helpful.