Loop through sub XmlNodeList with C# RSS

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  ska_mna

  Member

  10 Points

  39 Posts

  Loop through sub XmlNodeList with C#

  Apr 11, 2007 02:49 PM|LINK

  HI all,

  I've searched for an answer to this, as I'm sure it will have been asked before, but can't find anything. It's quite a simple query..

  I'm reading from a XML feed from a URL and can successfully loop through a node list for a top level node. However, within the Article node is a node called Categories, as an article can be associated with multiple categories. I then need to loop through this node list within each Article. In VB, I can do this as below, but I need to convert this to C# and can't find the equivalent

  VB.NET:

  Dim xtr As XmlTextReader = New XmlTextReader("http://feed.url.com")
          xtr.WhitespaceHandling = WhitespaceHandling.None
          Dim X As New XmlDocument
          X.Load(xtr)
  
  
        
  
          If Not X Is Nothing Then
              
  
              Try
                  Dim ArticleList As XmlNodeList = X.SelectNodes("InfoStreamResults/Article")
                  Dim Article As XmlNode
  
  
                
  
                  For Each Article In ArticleList
                    
  
  
  
                      Dim CatNodesList As XmlNodeList = Article.SelectNodes("Categories/Category")
                      Dim category As XmlNode
                      For Each category In CatNodesList
  
  
                          ' do stuff, i.e.
  
  			If Not Article.SelectSingleNode("nodename") Is Nothing Then
                          	nodename= safeEncode(Article.SelectSingleNode("nodename").Value)
                      	End If
  
  
  
  
                      Next
  
  
                  Next
  
  
              Catch ex As Exception
  
  
                ' exception
  
              End Try
          End If

   

  II can do the outer loop in C# fine, but when it comes to the equivalent of lines 17 to 28 as above, this DOESN'T work;

  C#:

  1    foreach (XmlNode category in Article.SelectNodes("Categories/Category"))
  2    {
  3       categoryID = category.SelectSingleNode("@ID").Value;
  4       categoryName = EncodeIt(category.SelectSingleNode("category").InnerText);
  5    }
  

  So how do I loop through a set of sub nodes within a node using foreach as I do in VB.NET, but in C#?

  Thanks, hope that makes sense.

• • Reply
  

  Haissam

  All-Star

  37421 Points

  5632 Posts

  Re: Loop through sub XmlNodeList with C#

  Apr 11, 2007 09:51 PM|LINK

  Try the below code

  if(X != null)

  {

  try

  {

  XmlNodeList ArticleList = X.SelectNodes("InfoStreamResults/Article");

  foreach(XmlNode Article in ArticleList)

  {

  XmlNodeList CatNodesList = Article.SelectNodes("Categories/Category");

  foreach( XmlNode category in CatNodesList)

  {

  //do stuff

  if(Article.SelectSingleNode("nodename") != null)

  {

  nodename = safeEncode(Article.SelectSingleNode("nodename").Value);

  }

  }

  }

  }

  catch

  {

  }

  }

  HC

  Haissam Abdul Malak
  MCAD.NET
  | Blog |
  • Marked as answer by Young Fang - MSFT on Apr 16, 2007 01:13 AM
• • Reply
  

  ska_mna

  Member

  10 Points

  39 Posts

  Re: Loop through sub XmlNodeList with C#

  Apr 12, 2007 08:17 PM|LINK

  Thanks very much for the reply. I've tried your suggested code and it does seem to loop though now, so that's great. However, it doesn't write out the value for categoryName. My code now is: 

  XmlTextReader xtr = new XmlTextReader("http://url.feed.com"); 
      xtr.WhitespaceHandling = WhitespaceHandling.None;
  
  
      XmlDocument X = new XmlDocument();
      X.Load(xtr);
  
  
      if (!(X == null))
      {
          try
          {
              XmlNodeList ArticleList = X.SelectNodes("InfoStreamResults/Article");
              foreach(XmlNode Article in ArticleList)
              {
                  
  
                  try
                  {
                      XmlNodeList CatNodesList = Article.SelectNodes("Categories/Category");
                      foreach( XmlNode category in CatNodesList)
                      {
                        
  
                          if (Article.SelectSingleNode("Category") != null)
                          {
                              categoryName = EncodeIt(Article.SelectSingleNode("Category").Value);
                              Response.Write(categoryName);
                              Response.Write("<br />");
                          }
  
  
                      }
  
  
                  }
                  catch (Exception ex)
                  {
                      Response.Write(ex);
                      Response.Write("<br />");
  
  
                  }
    
  
  
  
              }
          }
          catch (Exception ex)
          {
              Response.Write(ex);
          }
      }

  In the above, we don't enter the if statement on line 22. Is this the right way of referencing the node? I would have thought that now we are in another foreach loop, it would become  category.SelectSingleNode("category"). But I tried that and that didn't work either.

   Incidentally, a sample of my XML looks like this;

    

   
  <InfoStreamResults Copyright="(c) 2006 xxxx." ArticleCount="1">
  <Article Created="12:05:00" ID="1111">
    <Heading>heading title</Heading> 
    <Date>11/11/1111</Date> 
  <Contents>
  ![CDATA[ blah blah ]]> 
    </Contents>
  
  <Categories>
    <Category ID="11111">cat 1</Category>
  <Category ID="11112">cat 2</Category>
    </Categories>
    </Article>
  
  </InfoStreamResults>

   

  You can see the Categories node as above and the two values inside it. How do you loop through each article, then loop through each set of Categories inside each Article, and get the value of each Category? Getting there - any more pointers much appreciated.

• • Reply
  

  ska_mna

  Member

  10 Points

  39 Posts

  Re: Loop through sub XmlNodeList with C#

  Apr 12, 2007 08:17 PM|LINK

  Thanks very much for the reply. I've tried your suggested code and it does seem to loop though now, so that's great. However, it doesn't write out the value for categoryName. My code now is: 

  XmlTextReader xtr = new XmlTextReader("http://url.feed.com"); 
      xtr.WhitespaceHandling = WhitespaceHandling.None;
  
  
      XmlDocument X = new XmlDocument();
      X.Load(xtr);
  
  
      if (!(X == null))
      {
          try
          {
              XmlNodeList ArticleList = X.SelectNodes("InfoStreamResults/Article");
              foreach(XmlNode Article in ArticleList)
              {
                  
  
                  try
                  {
                      XmlNodeList CatNodesList = Article.SelectNodes("Categories/Category");
                      foreach( XmlNode category in CatNodesList)
                      {
                        
  
                          if (Article.SelectSingleNode("Category") != null)
                          {
                              categoryName = EncodeIt(Article.SelectSingleNode("Category").Value);
                              Response.Write(categoryName);
                              Response.Write("<br />");
                          }
  
  
                      }
  
  
                  }
                  catch (Exception ex)
                  {
                      Response.Write(ex);
                      Response.Write("<br />");
  
  
                  }
    
  
  
  
              }
          }
          catch (Exception ex)
          {
              Response.Write(ex);
          }
      }

  In the above, we don't enter the if statement on line 22. Is this the right way of referencing the node? I would have thought that now we are in another foreach loop, it would become  category.SelectSingleNode("category"). But I tried that and that didn't work either.

   Incidentally, a sample of my XML looks like this;

    

   
  <InfoStreamResults Copyright="(c) 2006 xxxx." ArticleCount="1">
  <Article Created="12:05:00" ID="1111">
    <Heading>heading title</Heading> 
    <Date>11/11/1111</Date> 
  <Contents>
  ![CDATA[ blah blah ]]> 
    </Contents>
  
  <Categories>
    <Category ID="11111">cat 1</Category>
  <Category ID="11112">cat 2</Category>
    </Categories>
    </Article>
  
  </InfoStreamResults>

   

  You can see the Categories node as above and the two values inside it. How do you loop through each article, then loop through each set of Categories inside each Article, and get the value of each Category? Getting there - any more pointers much appreciated.

• • Reply
  

  ska_mna

  Member

  10 Points

  39 Posts

  Re: Loop through sub XmlNodeList with C#

  Apr 12, 2007 08:19 PM|LINK

  Oops, double post, sorry.
• • Reply
  

  Haissam

  All-Star

  37421 Points

  5632 Posts

  Re: Loop through sub XmlNodeList with C#

  Apr 12, 2007 08:32 PM|LINK

  Below is your code

          if (!(X == null))
          {
              try
             {
                 XmlNodeList ArticleList = X.SelectNodes("InfoStreamResults/Article");
                 foreach(XmlNode Article in ArticleList)
                 {
                    
                     try
                     {
                         XmlNodeList CatNodesList = Article.SelectNodes("Categories/Category");
                         foreach( XmlNode category in CatNodesList)
                         {
                          
                             if (category != null)
                             {
                                string categoryName = category.InnerText;
                                 Response.Write(categoryName);
                                 Response.Write("<br />");
                             }
    
                         }
    
       }
                     catch (Exception ex)
                     {
                         Response.Write(ex);
                         Response.Write("<br />");
    
                     }
      
    
                 }
             }
             catch (Exception ex)
             {
                 Response.Write(ex);
             }
         }

  HC

  -----

  Mark it as answered if it helped you

  Haissam Abdul Malak
  MCAD.NET
  | Blog |
  • Marked as answer by Young Fang - MSFT on Apr 16, 2007 01:08 AM
• • Reply
  

  ska_mna

  Member

  10 Points

  39 Posts

  Re: Loop through sub XmlNodeList with C#

  Apr 16, 2007 10:21 AM|LINK

  Brilliant, thanks  - that's worked.
• • Reply
  

  NathanC

  Member

  21 Points

  18 Posts

  Re: Loop through sub XmlNodeList with C#

  Jul 09, 2008 10:50 AM|LINK

  Hi,

   I am having a very similar problem, except it's slightly more complicated. I need to check the attribute value before deciding what to do with the inner text. I am converting a large xml file (100,000 lines) to a csv file, except i'm struggling with the custom attributes section - see below:

   

  <product product-id="048002347">
      <display-name>Cotton crew-neck printed T-shirt</display-name>
      <long-description>Superdry cotton short-sleeved T-shirt with Osaka 6 print emblazoned across chest.</long-description>
      <online-flag>false</online-flag>
      <available-flag>true</available-flag>
      <searchable-flag>true</searchable-flag>
      <tax-class-id>default</tax-class-id>
      <brand>Superdry</brand>
      <manufacturer-name>Superdry</manufacturer-name>
      <custom-attributes>
        <custom-attribute attribute-id="Calendar Event">N/A</custom-attribute>
        <custom-attribute attribute-id="Care Instructions">Machine Wash 30°C</custom-attribute>
        <custom-attribute attribute-id="Colour">Black</custom-attribute>
        <custom-attribute attribute-id="Cuff Type">N/A</custom-attribute>
        <custom-attribute attribute-id="Exclusive">N/A</custom-attribute>
        <custom-attribute attribute-id="Fabric">Cotton</custom-attribute>
        <custom-attribute attribute-id="Fair Trade">N/A</custom-attribute>
        <custom-attribute attribute-id="Gender">Men</custom-attribute>
        <custom-attribute attribute-id="Guarantee">N/A</custom-attribute>
        <custom-attribute attribute-id="House of Fraser Magazine">No</custom-attribute>
        <custom-attribute attribute-id="Organic">No</custom-attribute>
        <custom-attribute attribute-id="Parent Colour">Black</custom-attribute>
        <custom-attribute attribute-id="Parent Style">TOPS</custom-attribute>
        <custom-attribute attribute-id="Range">PRE-SEASON/TRANSITIONAL</custom-attribute>
        <custom-attribute attribute-id="Recycled">N/A</custom-attribute>
        <custom-attribute attribute-id="Size">XL</custom-attribute>
        <custom-attribute attribute-id="Style">TOP- T-SHIRT</custom-attribute>
        <custom-attribute attribute-id="Television Line">No</custom-attribute>
        <custom-attribute attribute-id="Web Supply Lane">iForce Deliveries</custom-attribute>
        <custom-attribute attribute-id="qosListID">QOS1</custom-attribute>
        <custom-attribute attribute-id="sellByUnit">false</custom-attribute>
        <custom-attribute attribute-id="COMPOSITION">100% Cotton</custom-attribute>
      </custom-attributes>
    </product>

  What I need to do is first check for the attribute-id value, i.e.

   
  XmlNodeList attributeList = n.SelectNodes("custom-attributes/custom-attribute");
  string calendar = "null";
  foreach (XmlNode a in attributeList)
  {
     if (a.Attributes["attribute-id"].Value == "Calendar Event") 
     { 
         calendar = a.InnerText; 
     }              
  }
   

  And then assign it the inner value if it exists, else leave the string as null. Now all that's happening is the string is returned as nul every single time.

  I am using a textwriter to write the data to a textfile, so a shortened version of the code (with everything required for this purpose is below)

   
  int id = 0;
  
              string CSVFile = "HOFProds.txt";
              TextWriter tw = new StreamWriter(CSVFile);
              tw.WriteLine("id|product-id|ean|display-name|long-description|online-flag|available-flag|" +
                  "searchable-flag|tax-class-id|brand|manufacturer-name|Calendar Event|Care Instructions|Colour|" +
                  "Cuff Type|Exclusive|Fabric|Fair Trade|Gender|Guarantee|House of Fraser Magazine|Organic|Parent Colour|" +
                  "Parent Style|Range|Recycled|Size|Style|Television Line|Web Supply Lane|qosListID|sellByUnit|COMPOSITION|" +
                  "PrimaryImage|SecondaryImage1|SecondaryImage2|Sizing|Finish|Material|Skin Type|Animal Tested|" +
                  "WEIGHT|UnitMeasure|UnitQty|UnitQtyPrd|SecondaryImage3|SecondaryImage4|SecondaryImage5");
  
              XmlDocument hofProds = new XmlDocument();
              hofProds.Load("StagingHofCatalog.xml");
  
              XmlNodeList productList = null;
              productList = hofProds.GetElementsByTagName("product");
  
              foreach (XmlNode n in productList)
              {
                  id = id + 1;
                  string ean = "null";
                  string displayName = "null";
                  string longDescription = "null";
                  string onlineFlag = "null";
                  string availableFlag = "null";
                  string searchableFlag = "null";
                  string taxClass = "null";
                  string brand = "null";
                  string manufacturerName = "null";
  
                  if (n["ean"] != null) { ean = n["ean"].InnerText; }
  
                  if (n["display-name"] != null) { displayName = n["display-name"].InnerText; }
  
                  if (n["long-description"] != null) { longDescription = n["long-description"].InnerText; }
  
                  if (n["online-flag"] != null) { onlineFlag = n["online-flag"].InnerText; }
  
                  if (n["available-flag"] != null) { availableFlag = n["available-flag"].InnerText; }
  
                  if (n["searchable-flag"] != null) { searchableFlag = n["searchable-flag"].InnerText; }
  
                  if (n["tax-class-id"] != null) { taxClass = n["tax-class-id"].InnerText; }
  
                  if (n["brand"] != null) { brand = n["brand"].InnerText; }
  
                  if (n["manufacturer-name"] != null) { manufacturerName = n["manufacturer-name"].InnerText; }
  
                  string calendar = "null"; string care = "null"; string colour = "null"; string cuff = "null"; string exclusive = "null";
                  string fabric = "null"; string fairtrade = "null"; string gender = "null"; string guarantee = "null";
                  string hofmagazine = "null"; string organic = "null";
                  string parentColour = "null"; string parentStyle = "null"; string range = "null"; string recycled = "null";
                  string size = "null"; string style = "null"; string tvLine = "null"; string webSupplyLane = "null"; string qosListID = "null";
                  string sellByUnit = "null";
                  string composition = "null"; string primaryImage = "null"; string SecondaryImage1 = "null"; string SecondaryImage2 = "null"; string Sizing = "null";
                  string Finish = "null"; string Material = "null"; string SkinType = "null"; string AnimalTested = "null";
                  string WEIGHT = "null"; string UnitMeasure = "null"; string UnitQty = "null"; string UnitQtyPrd = "null";
                  string SecondaryImage3 = "null"; string SecondaryImage4 = "null"; string SecondaryImage5 = "null";
  
                  XmlNodeList attributeList = n.SelectNodes("custom-attributes/custom-attribute");
                  foreach (XmlNode a in attributeList)
                  {
                      if (a.Attributes["attribute-id"].Value == "Calendar Event") { calendar = a.InnerText; }
                  }
  
                  tw.WriteLine(id + "|" + n.Attributes["product-id"].Value + "|" + ean + "|" + displayName + "|" +
                      longDescription + "|" + onlineFlag + "|" +
                      availableFlag + "|" + searchableFlag + "|" +
                      taxClass + "|" + brand + "|" +
                      manufacturerName + "|" + calendar + "|" + care + "|" + colour + "|" + cuff + "|" + exclusive + "|" + fabric + "|" +
                      fairtrade + "|" + gender + "|" + guarantee + "|" + hofmagazine + "|" + organic + "|" + parentColour + "|" +
                      parentStyle + "|" + range + "|" + recycled + "|" + size + "|" + style + "|" + tvLine + "|" +
                      webSupplyLane + "|" + qosListID + "|" + sellByUnit + "|" + composition + "|" +
                      primaryImage + "|" + SecondaryImage1 + "|" + SecondaryImage2 + "|" + Sizing + "|" +
                      Finish + "|" + Material + "|" + SkinType + "|" + AnimalTested + "|" + WEIGHT + "|" + UnitMeasure + "|" +
                      UnitQty + "|" + UnitQtyPrd + "|" + SecondaryImage3 + "|" + SecondaryImage4 + "|" + SecondaryImage5);
              }
              tw.Close();
   

   Just to clarify that before we get to the custom-attributes section, the program works fine because the data is output correctly. It's only when I get to analyzing the custom-attributes section that does the data become construed.

  I have tried to use a separate node list and insert the attributes that way except this doesn't have no binding or sequence then as sometimes the attributes may not exist, this is why i have to allow for them all and check them, if they are there then insert them, if not then insert null.

   Hopefully I have been clear,

  Many thanks for any help in advance,

  ChanandCo

  Please mark as the answer if your problem has been resolved as a result of my posting - Ta
  
  Price is what you pay; value is what get;
• • Reply
  

  Anargeek77

  Member

  2 Points

  1 Post

  Re: Loop through sub XmlNodeList with C#

  Sep 17, 2008 03:26 AM|LINK

  Haissam over a year ago you made this one.

       if (!(X == null))
          {
              try
             {
                 XmlNodeList ArticleList = X.SelectNodes("InfoStreamResults/Article");
                 foreach(XmlNode Article in ArticleList)
                 {
                    
                     try
                     {
                         XmlNodeList CatNodesList = Article.SelectNodes("Categories/Category");
                         foreach( XmlNode category in CatNodesList)
                         {
                          
                             if (category != null)
                             {
                                string categoryName = category.InnerText;
                                 Response.Write(categoryName);
                                 Response.Write("<br />");
                             }
    
                         }
    
       }
                     catch (Exception ex)
                     {
                         Response.Write(ex);
                         Response.Write("<br />");
    
                     }
      
    
                 }
             }
             catch (Exception ex)
             {
                 Response.Write(ex);
             }
  

   

  I'm curious to know how would you accomplish same results using LINQ to XML?

   

  -Anargeek77

• • Reply
  

  NathanC

  Member

  21 Points

  18 Posts

  Re: Loop through sub XmlNodeList with C#

  Sep 17, 2008 07:07 AM|LINK

  Hey, you would need to convert your XMLDocument to an XDocument/Xelement to be able to use it with LINQ.

  XElement elements = XElement.Load(pathToFile);
  
  
  var ranges = from r in elements.DescendantsAndSelf("range")
              select r;
  
  
  foreach (var x in ranges)
  {
  //do your work here.
  }

   HTH's :)

   

  Please mark as the answer if your problem has been resolved as a result of my posting - Ta
  
  Price is what you pay; value is what get;