Parse nested XML from URL

Question

I'm currently working on a .NET 4.6 console application. I need to parse a nested XML from an URL and transform the XML into an object list.

The URL for the sample XML is the following:

https://www.w3schools.com/xml/cd_catalog.xml

The XML looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<CATALOG>
    <CD>
        <TITLE>Empire Burlesque</TITLE>
        <ARTIST>Bob Dylan</ARTIST>
        <COUNTRY>USA</COUNTRY>
        <COMPANY>Columbia</COMPANY>
        <PRICE>10.90</PRICE>
        <YEAR>1985</YEAR>
    </CD>
    <CD>
        <TITLE>Hide your heart</TITLE>
        <ARTIST>Bonnie Tyler</ARTIST>
        <COUNTRY>UK</COUNTRY>
        <COMPANY>CBS Records</COMPANY>
        <PRICE>9.90</PRICE>
        <YEAR>1988</YEAR>
    </CD>
</CATALOG>

My corresponding C# classes look like this:

[XmlRoot(ElementName = "CATALOG")]
public class Catalog
{
    [XmlElement("CD")]
    List<Cd> Cds { get; set; }
}

[XmlRoot(ElementName = "CD")]
public class Cd
{
    [XmlElement("TITLE")]
    public string Title { get; set; }
    [XmlElement("ARTIST")]
    public string Artist { get; set; }
    [XmlElement("COUNTRY")]
    public string Country { get; set; }
    [XmlElement("COMPANY")]
    public string Company { get; set; }
    [XmlElement("PRICE")]
    public double Price { get; set; }
    [XmlElement("YEAR")]
    public int Year { get; set; }
}

My program class looks like this:

class Program
{
    static void Main(string[] args)
    {
        Init();      
    }

    public static void Init() {

        var url = "https://www.w3schools.com/xml/cd_catalog.xml";

        XmlDocument myXmlDocument = new XmlDocument();
        myXmlDocument.Load(url);

        var catalog = myXmlDocument.InnerXml.ToString();

        var result = Deserialize<Catalog>(catalog);
        // result is null :(

        Console.ReadKey();
    }

    public static T Deserialize<T>(string xmlText)
    {
        try
        {
            var stringReader = new StringReader(xmlText);
            var serializer = new XmlSerializer(typeof(T));
            return (T)serializer.Deserialize(stringReader);
        }
        catch (Exception ex)
        {
            throw;
        }
    }
}

So far so good, my variable catalog consists out of an XML string, but somehow the XML doesn't get parsed correctly. I always get null as a return result. Perhaps it's because of my class definitions.

What do you think, do you have an idea on how to solve this issue? To retrieve an List<Cd> instead of null.

Answer 1

List<Cd> Cds { get; set; }

Change this line to

Public List<Cd> Cds { get; set; }

Answer 2

The error is very subtle. You have done everything right, but you missed to add the public access qualifier in your Catalog class, on the list of Cd like so:

[XmlRoot(ElementName = "CATALOG")]
public class Catalog
{
    [XmlElement("CD")]
    public List<Cd> Cds { get; set; }
}

Since the access qualifiers default to private, the deserializer is having a hard time finding the correct property to deserialize the XML into.