Question

I am trying to figure out how to group XML nodes with the same name but different values.

The web service I’m using returns an XmlElement that looks like this:

<Items>
    <Item>
        <Name name="Name">Item 1</Name>
        <Description name="Description">
            Lorem ipsum dolor sit amet, consectetur adipiscing elit.
        </Description>
        <AssociatedItems name="Associated Items">Item 2</AssociatedItems>
        <AssociatedItems name="Associated Items">Item 3</AssociatedItems>
        <AssociatedItems name="Associated Items">Item 4</AssociatedItems>
        <AssociatedItems name="Associated Items">Item 5</AssociatedItems>
    </Item>
</Items>

I am transforming each node into an HTML tag

protected void lnkItem_Click(object sender, EventArgs e)
{
    LinkButton link = (LinkButton)sender;
    GridViewRow row = (GridViewRow)link.Parent.Parent;

    string id = gv.DataKeys[row.RowIndex]["id"].ToString();

    PublicApiAsmxServiceSoapClient service = new PublicApiAsmxServiceSoapClient("PublicApiAsmxServiceSoap", WEB_SERVICE_URL);
    XmlElement xml = service.ItemGetAsXml(id);
    XElement nodes = XElement.Parse(xml.InnerXml);

    foreach (var node in nodes.Elements())
    {
        InsertHTML(node);
    }
}

private void InsertHTML(XElement node)
{
    if (node.Value == string.Empty)
        return;

    pnl.ContentTemplateContainer.Controls.Add(new LiteralControl(String.Format("<h3>{0}</h3>", node.Attribute("name").Value)));
    pnl.ContentTemplateContainer.Controls.Add(new LiteralControl(String.Format("<p>{0}</p>", node.Value)));
}

With my code right now, the HTML output would be:

<h3>Name</h3>
<p>Item 1</p>
<h3>Description</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
<h3>Associated Items</h3>
<p>Item 2</p>
<h3>Associated Items</h3>
<p>Item 3</p>
<h3>Associated Items</h3>
<p>Item 4</p>
<h3>Associated Items</h3>
<p>Item 5</p>

Is there a way to group the same nodes as an unordered list? Something like this, perhaps:

<h3>Name</h3>
<p>Item 1</p>
<h3>Description</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
<h3>Associated Items</h3>
<ul>
    <li>Item 2</li>
    <li>Item 3</li>
    <li>Item 4</li>
    <li>Item 5</li>
</ul>

Thank you! (Please be nice.)

PS
The child nodes that repeat aren’t limited to AssociatedTerms only. There are possibly more child nodes of the same name that repeat.

Answer 1

It would be easiest using a generator to generate the elements based on the groupings since what gets generated depends on how many duplicates there are.

As I understand it, you’re grouping by element name and the value of the name attributes. Then generating an h3 followed by an element depending on if there are multiple elements in the group. p if there’s a single element or a ul if there are multiple elements.

IEnumerable<XElement> GroupedElements(XElement root)
{
    var groupedItems =
        from element in root.Elements()
        group element
        by new
        {
            Element = element.Name,
            Name = (string)element.Attribute("name"),
        };
    foreach (var g in groupedItems)
    {
        yield return new XElement("h3", g.Key.Name);
        var isMultiple = g.Skip(1).Any();
        if (isMultiple)
            yield return new XElement("ul",
                from item in g
                select new XElement("li", item.Value.Trim())
            );
        else
            yield return new XElement("p", g.Single().Value.Trim());
    }
}

var xmlStr = @"<Items>
    <Item>
        <Name name=""Name"">Item 1</Name>
        <Description name=""Description"">
            Lorem ipsum dolor sit amet, consectetur adipiscing elit.
        </Description>
        <AssociatedItems name=""Associated Items"">Item 2</AssociatedItems>
        <AssociatedItems name=""Associated Items"">Item 3</AssociatedItems>
        <AssociatedItems name=""Associated Items"">Item 4</AssociatedItems>
        <AssociatedItems name=""Associated Items"">Item 5</AssociatedItems>
    </Item>
</Items>";
var doc = XDocument.Parse(xmlStr);
var transformed = new XElement("div", 
    from item in doc.XPathSelectElements("/Items/Item")
    select GroupedElements(item)
);

Yields the following:

<div>
  <h3>Name</h3>
  <p>Item 1</p>
  <h3>Description</h3>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
  <h3>Associated Items</h3>
  <ul>
    <li>Item 2</li>
    <li>Item 3</li>
    <li>Item 4</li>
    <li>Item 5</li>
  </ul>
</div>