LINQ to XML specific question on extracting data

Hello,

I have an XML defined as follow

<showschedule>
        <fall name="FAL" text="Y" index="1"/>
        <spring name="SPR" text="Y" index="2"/>
        <winter name="WIN" text="Y" index="3"/>
        <summer name="SUM" text="Y" index="4"/>
    </showschedule>

I want to sort it using LINQ to XML and then put the sorted value of name into 4 hidden field according to thier index
However I am not sure how to do it and I currently just extract data by LINQ with out using sort.

Anyone could help on this?

The below is the code I used now..I think there should be a smarter way to do it with LINQ?

Protected Sub LoadSchedule()
        Dim xele As XElement = XElement.Load(MapPath("~\xml\course_desc.xml"))
        Dim tarlist As New ArrayList
        tarlist.Add("fall")
        tarlist.Add("spring")
        tarlist.Add("winter")
        tarlist.Add("summer")
        For Each taritem In tarlist
            Dim xitems = From x In xele.Descendants("showschedule").Descendants(taritem.ToString)

            For Each x In xitems
                If x.@index = "1" Then
                    Sch_1.Value = x.@name
                ElseIf x.@index = "2" Then
                    Sch_2.Value = x.@name
                ElseIf x.@index = "3" Then
                    Sch_3.Value = x.@name
                ElseIf x.@index = "4" Then
                    Sch_4.Value = x.@name
                End If
            Next

        Next

    End Sub

Great THanks!

Re: LINQ to XML specific question on extracting data

I'm not opposed to the way you're doing it. I wrote up the below in LINQPad, but its not much more concise, but I think its easier to read (its in C#):

string xml = "<showschedule><fall name=\"FAL\" text=\"Y\" index=\"1\"/><spring name=\"SPR\" text=\"Y\" index=\"2\"/><winter name=\"WIN\" text=\"Y\" index=\"3\"/><summer name=\"SUM\" text=\"Y\" index=\"4\"/></showschedule>";

XElement ele = XElement.Parse(xml);

var query = (from x in ele.Descendants()
	  select new
	  {
	      Name = x.Attribute("name").Value,
	      Text = x.Attribute("text").Value,
	      Index = x.Attribute("index").Value
	  }).OrderBy(x => x.Index).ToList();
			
Sch_1.Value = query[0].Name;
Sch_2.Value = query[1].Name;
Sch_3.Value = query[2].Name;
Sch_4.Value = query[3].Name;

Re: LINQ to XML specific question on extracting data

@ Bee

//I assume you want to sort on the Index, hence i have changed the index sequence in you
        //present XML.
        string mySchedules = "<showschedule>" +
                                "<fall name=\"FAL\" text=\"Y\" index=\"3\"/>" +
                                "<spring name=\"SPR\" text=\"Y\" index=\"2\"/>" +
                                "<winter name=\"WIN\" text=\"Y\" index=\"1\"/>" +
                                "<summer name=\"SUM\" text=\"Y\" index=\"4\"/>" +
                            "</showschedule>";
        
        XElement xShows = XElement.Parse(mySchedules);

        //This is how you sort
        IEnumerable<XElement> sortShows = from s in xShows.Descendants()
                        orderby (int)s.Attribute("index")
                        select s;

        //This will give you output in the object  sortShows as below.

        /*
                            "<showschedule>" +
                                "<winter name=\"WIN\" text=\"Y\" index=\"1\"/>" +
                                "<spring name=\"SPR\" text=\"Y\" index=\"2\"/>" +
                                 "<fall name=\"FAL\" text=\"Y\" index=\"3\"/>" +
                                "<summer name=\"SUM\" text=\"Y\" index=\"4\"/>" +
                            "</showschedule>";
         
         */

        //Now instead of writing nested if else, all you have to do is as below.
        
        string commaSeperatedSortedMsg = "";
        foreach (XElement xE in sortShows)
        {
            commaSeperatedSortedMsg += " | " + xE.Attribute("index").Value + xE.Attribute("name").Value;
            
        }

Re: LINQ to XML specific question on extracting data

Cool! Both works!

But i want to have a follow up question,

If I want to modify one of the item, say, Winter only,

How could I access this specified item?

The below is what i use after converting to VB

Dim xele As XElement = XElement.Load(MapPath("~\xml\course_desc.xml"))

        Dim xitems = (From x In xele.Descendants("showschedule").Descendants() _
                     Select New With { _
                            .Sqlname = x.Attribute("sqlname").Value, _
                            .Sqlshow = x.Attribute("show").Value, _
                            .Index = x.Attribute("index").Value, _
                            .Name = x.Attribute("name").Value _
                      }).OrderBy(Function(x) x.Index).ToList()

Re: LINQ to XML specific question on extracting data

//To update the text of Winter you might want to do this.

        string mySchedules = "<showschedule>" +
                              "<fall name=\"FAL\" text=\"Y\" index=\"3\"/>" +
                              "<spring name=\"SPR\" text=\"Y\" index=\"2\"/>" +
                              "<winter name=\"WIN\" text=\"Y\" index=\"1\"/>" +
                              "<summer name=\"SUM\" text=\"Y\" index=\"4\"/>" +
                          "</showschedule>";

        XElement xShows = XElement.Parse(mySchedules);

        IEnumerable<XElement> singleSchedule = from s in xShows.Descendants()
                                          where ((string)s.Attribute("name").Value.ToLower()).Equals("win")
                                          select s;



        foreach (XElement xWin in singleSchedule)
        {
            xWin.SetAttributeValue("text", "N");
        }

        string myOutput = xShows.ToString();

        /*
         It will give you output as ::see the text of Winter.::
         *
         *                  <showschedule>
                              <fall name="FAL" text="Y" index="3"/>
                              <spring name="SPR" text="Y" index="2"/>
                              <winter name="WIN" text="N" index="1"/>
                              <summer name="SUM" text="Y" index="4"/>
                          </showschedule>
         *
         
         */

Re: LINQ to XML specific question on extracting data

Hello Kavita,

After I have select this node

How can I delete this? THere is no method call to remove the node..?

Dim xitem = (From x In xele.Descendants(name).Descendants("desc").Descendants() _
                     Select New With { _
                            .desc = x.Attribute("text").Value
                     }).Where(Function(x) x.desc = ctl.Text).FirstOrDefault

Re: LINQ to XML specific question on extracting data

//I dont seem to find the DESC element mentioned in you recent post, hence am caryying forward it
        // with below XML only. Lets say you want to delete the element having name="WIN"
        string mySchedules = "<showschedule>" +
                              "<fall name=\"FAL\" text=\"Y\" index=\"3\"/>" +
                              "<spring name=\"SPR\" text=\"Y\" index=\"2\"/>" +
                              "<winter name=\"WIN\" text=\"Y\" index=\"1\"/>" +
                              "<summer name=\"SUM\" text=\"Y\" index=\"4\"/>" +
                          "</showschedule>";

        XElement xShows = XElement.Parse(mySchedules);

        IEnumerable<XElement> singleSchedule = from s in xShows.Descendants()
                                               where ((string)s.Attribute("name").Value.ToLower()).Equals("win")
                                               select s;

        singleSchedule.Remove();

        string myOutput = xShows.ToString();

        ///*
        // It will give you output as ::see the text of Winter.::
        // *
        // *                  <showschedule>
        //                      <fall name="FAL" text="Y" index="3"/>
        //                      <spring name="SPR" text="Y" index="2"/>
        //                      <summer name="SUM" text="Y" index="4"/>
        //                  </showschedule>
        // *

        // */

Re: LINQ to XML specific question on extracting data

Hi Kavita,

No problem to use the previous XML file.

is it if I dont use IEnumerable, I cant use that way to remove?

I tryed something like this in VB, but seems not working..

Dim xele As XElement = XElement.Load(MapPath("~\xml\course_desc.xml"))

        Dim xitems As IEnumerable(Of XElement) = From x In xele.Descendants("core").Descendants("desc").Descendants() _
                    Where x.Attribute("name").Value.Equals("Students with CISSP, CISM or GCIH professional certification may apply for substitution for ISOM 5280.")