Question

I’m parsing an xml document, that is like this:

<?xml version="1.0" encoding="UTF-8" ?>
....
    <maj>true</maj>
    <data>
        <c>2</c>
        <t>0</t>
        <r>168</r>
        <r>La rentrée Auchan</r>
        <r>0</r>
        <r>2012-08-21 00:00:00</r>
        <r>2012-08-28 00:00:00</r>
        <r>56</r>
        <r>VL</r>

        <c>2</c>
        <t>1</t>
        ...
    </data>

I want to get what there is inside the array “r”, but only the first position 1 the position 5 and 6, and only where t=0
I’ve tried to work like this, I have a listbox that bind the data :

XDocument XMLtxt = JsonConvert.DeserializeXNode(e.Result);

listClients.ItemsSource =
    from c in XMLtxt.Descendants()
    select new JsonB()
    {
        t=c.Element("t").Value.Where(x=>(int) x==0), 
        r1=c.Element("r").Select(..
    }

the jsonB :

 public class JsonB
 {
     public int c { get; set; }
     public int t { get; set; }
     public string r1 { get; set; }
     public int r5 { get; set; }
     public string r6 { get; set; }
     public object[] r { get; set; }
 } 

I really need help, thank you

Answer 1

The XML is a bit ill-structured, so you will have to fix this first with your code.. For starters, in a simple way you can sequentially read/parse the contents so that the structure of the record is clear, and then filter them:

• prepare a list of JsonB objects – name it i.e. ‘allRecords’
• prepare a variable of type JsonB – name it i.e. ‘lastRecord’
• prepare a variable of type int – name it i.e. ‘numberOfRs’
• get the <data> tag
• loop over all of its direct children, and for each child:
  • check the name of the child
  • if it is <c>:
    • create new JsobB and put it into lastRecord
    • reset the numberOfRs to zero
    • add the lastRecord to the allRecords list
    • read the c value and put it into lastRecord.c
  • if it is <t>:
    • read the value and put it into lastRecord.t
  • if it is <r>:
    • add 1 to the numberOfRs
    • if numberOfRs is 1, 5 or 6:
    • read the value and put it into lastRecord.r1 or r5 or r6

this way, you will have a list allRecords with pretty objects, and you can simply .Where(item => item.t ==0) on it.

However, you may notice it to be very ‘wasteful’ if many of such objects are to be ignored. Then, you could adjust the sequential parser to filter then on-the-fly and thus behave like this

• prepare a list of JsonB objects – name it i.e. ‘allRecords’
• prepare a variable of type JsonB – name it i.e. ‘lastRecord’
• prepare a variable of type int – name it i.e. ‘numberOfRs’
• prepare a variable of type bool – name it i.e. ‘isInteresting’, preset it to false
• get the <data> tag
• loop over all of its direct children, and for each child:
  • check the name of the child
  • if it is <c>:
    • if isInteresting is true
      • add the lastRecord to the allRecords list
    • create new JsobB and put it into lastRecord
    • reset the numberOfRs to zero
    • add the lastRecord to the allRecords list reset the isInteresting to false
    • read the c value and put it into lastRecord.c
  • if it is <t>:
    • read the value and put it into lastRecord.t
    • if it was zero, set the isInteresting to true
  • if it is <r>:
    • add 1 to the numberOfRs
    • if numberOfRs is 1, 5 or 6:
    • read the value and put it into lastRecord.r1 or r5 or r6
• if isInteresting is true
  • add the lastRecord to the allRecords list

This way, you will end up with a list that is already filtered and all not interesting items will be GC’ed in the meantime. Please note that the ‘isinteresting – add to list’ is done twice: once before creatig new JsonB, and then also in the final step when all children has been read. If you forget about the check-add after the loop – you may sometimes accidentially skip/ignore the last record.