Reading Top Five records from XML file ......

Let say I have 100 articles in my XML file and I like to read the top most five articles, how would I do this?
I can read all the articles like this

DataSet ds = new DataSet();
ds.ReadXml(Server.MapPath("Articles.xml"));
DataView dv  = ds.Tables[0].DefaultView;

DataList1.DataSource = dv;
DataList1.DataBind();

But I don’t know how would I read top five articles from the xml file.
Thanks





XmlFile
--------------

<?xml version="1.0"?>
<articles>
    <article>
        <id>050</id>
        <title>Article 050 Title</title>
        <author>SomeGuy</author>
        <dateposted>10/22/2003</dateposted>
        <smalldescription>Small description</smalldescription>
        <longdescription>Long Description</longdescription>
        <code>Some code</code>
    </article>
</articles>


C# Code

private void Page_Load(object sender, System.EventArgs e)
{
      DataSet ds = new DataSet();
      ds.ReadXml(Server.MapPath("Articles.xml"));
      DataView dv  = ds.Tables[0].DefaultView;

      DataList1.DataSource = dv;
      DataList1.DataBind();
}




adamullahAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

ericsDevCommented:
**UNTESTESTED**

you can load the records into your DataView and then loop through the DataView and remove all but the rows you want to keep something like this.

for(int x = 0; x < dv.Rows.Count; x++)
{
if(x>=5)
{
dv.Rows[x].Delete();
}
}

I believe this will work unless there is a better way that someone else knows about :)
0
purpleblobCommented:
What about using XPath on the XML first to extract the required subset of article elements - something like

//article[position() <= 5]/*

where 5 is the first five elements


0
ericsDevCommented:
that should work as long as position() is a supported function by MS... I've found that alot of them aren't... you should be able to find that info here: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/xmlsdk/htm/xsd_ref_8nas.asp
0
Fundamentals of JavaScript

Learn the fundamentals of the popular programming language JavaScript so that you can explore the realm of web development.

purpleblobCommented:
Very good point re:support of the function position by MS

So I thought I should try this in .NET. It appears to work fine except I made a small mistake in the XPath statement it should have read

//article[position() <= 5]

Thus becomes

System.Xml.XmlNodeList nodes = xmldoc.SelectNodes("//article[position() <= 5]");

The /* will return the inner items within the top 5 elements as opposed to the elements themselves - whoops, sorry about that
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
ericsDevCommented:
purpleblob: good work, I will keep this method in mind.
0
adamullahAuthor Commented:
Thanks purpleblob, i also find a good site for XPath. http://www.w3schools.com/xpath/xpath_location.asp

Here is the modified code.


C# codebehind code
------------------------
private void Page_Load(object sender, System.EventArgs e)
{
      XmlDocument xd = new XmlDocument();
      XmlNodeList nl;

      xd.Load(Server.MapPath("Articles.xml"));

      nl = xd.SelectNodes("/articles/article[position() <=3]");
      
      lstArticles.DataSource = nl;
      lstArticles.DataBind();

}


aspx page code:
-------------------
<asp:datalist id="lstArticles" runat="server">
      <itemtemplate>
            <%# ((System.Xml.XmlNode)Container.DataItem).SelectSingleNode("id").InnerText %>
            <br>
            <%# ((System.Xml.XmlNode)Container.DataItem).SelectSingleNode("title").InnerText %>
      </itemtemplate>
</asp:datalist>



XmlFile
--------
<?xml version="1.0"?>
<articles>
    <article>
        <id>050</id>
        <title>Article 050 Title</title>
        <author>SomeGuy</author>
        <dateposted>10/22/2003</dateposted>
        <smalldescription>Small description</smalldescription>
        <longdescription>Long Description</longdescription>
        <code>Some code</code>
    </article>
</articles>
 
 
0
adamullahAuthor Commented:
purpleblob you got all the points............
0
purpleblobCommented:
Many thanks

Glad to have helped
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
C#

From novice to tech pro — start learning today.