Question

I have written:

        public string GetOutline(int indentLevel, XElement element)
        {
        StringBuilder result = new StringBuilder();


        result = result.AppendLine(new string('-', indentLevel * 2) + element.Name);

        foreach (var childElement in element.Elements())
        {
            result.Append(GetOutline(indentLevel + 3, childElement));
        }

        return result.ToString();
    }

The result of this recursive methond run on xml file shows:

    Videos
    ------Video
    ------------Title
    ------------Director
    ------------Actors
    ------------------Actor
    ------------------Actor
    ------------------Actor
    ------------------Actor
    ------------Length
    ------------Format
    ------------Rating
    ------Video
    ------------Title
    ------------Director
    ------------Length
    ------------Format
    ------------Rating
enter code here

But I would want the output to be like below:

    Videos
    ------Video
    ------------Title
    ------------Director
    ------------Actors
    ------------------Actor
    ------------Length
    ------------Format
    ------------Rating

How to edit the code ? Really struggling with this from yesterday …

Answer 1

Use linq grouping by name:

foreach (var childElement in element.Elements().GroupBy(childElement => childElement.Name))
{
    result.Append(GetOutline(indentLevel + 3, childElement.First()));
}

instead of:

foreach (var childElement in element.Elements())
{
    result.Append(GetOutline(indentLevel + 3, childElement.First()));
}

---

The only problem of this method is the use of First.
If you have, for example in your XML file:

<actors>
    <actor>
        <property/>
    </actor>
    <actor>
        <differentProperty/>
        <differentProperty2/>
    </actor>
</actors>

With grouping and First the result will be:

actors
----actor
--------property

How do you want the result to appear in this case?

actors
----actor
--------property
--------differentProperty
--------differentProperty2

or

actors
----actor
--------property
----actor
--------differentProperty
--------differentProperty2

or this case will not appear?

UPDATE:

Given your comment the solution would be:

public static string GetOutline(int indentLevel, XElement element)
{
    return GetGroupOutline(indentLevel, new[] {element});
}

/// <summary>
/// Returns the outline of the elements that constitute a group.
/// </summary>
/// <param name="indentLevel">Indent level.</param>
/// <param name="elements">Elements of a group (all the element of the collection must have the same <c>Name</c>)</param>
/// <returns>Outline of the group.</returns>
private static string GetGroupOutline(int indentLevel, IEnumerable<XElement> elements)
{
    StringBuilder result = new StringBuilder();

    // Adds the group name in the outline
    result = result.AppendLine(new string('-', indentLevel * 6) + elements.First().Name);

    foreach (var childGroup in from element in elements  // Gets each element in the group "elements"
                               from childElement in element.Elements()  // Gets their children
                               group childElement by childElement.Name into childGroup  // Groups the children of all elements by their name to a new group called "childGroup"
                               select childGroup)
        result.Append(GetGroupOutline(indentLevel + 1, childGroup));  // Shows the outline of the group called "groupChild"

    return result.ToString();
}