Can I serialize Anonymous Types as xml?

Question

I understood that anonymous types are marked private by the compiler and the properties are read-only. Is there a way to serialize them to xml (without deserialize) ? It wor

Answer 1

Thank you, excellent work @Matthew and @Martin.

I have made a couple of modification to accomodate Nullables and Enums. Also I have changed it so that array elements are named according to the name of the property + index.

Here is the code if anyone is interested

public static class ObjectExtensions {
    #region Private Fields
    private static readonly Type[] WriteTypes = new[] {
        typeof(string), typeof(DateTime), typeof(Enum), 
        typeof(decimal), typeof(Guid),
    };
    #endregion Private Fields
    #region .ToXml
    /// <summary>
    /// Converts an anonymous type to an XElement.
    /// </summary>
    /// <param name="input">The input.</param>
    /// <returns>Returns the object as it's XML representation in an XElement.</returns>
    public static XElement ToXml(this object input) {
        return input.ToXml(null);
    }

    /// <summary>
    /// Converts an anonymous type to an XElement.
    /// </summary>
    /// <param name="input">The input.</param>
    /// <param name="element">The element name.</param>
    /// <returns>Returns the object as it's XML representation in an XElement.</returns>
    public static XElement ToXml(this object input, string element) {
        return _ToXml(input, element);
    }

    private static XElement _ToXml(object input, string element, int? arrayIndex = null, string arrayName = null) {
        if (input == null)
            return null;

        if (String.IsNullOrEmpty(element)) {
            string name = input.GetType().Name;
            element = name.Contains("AnonymousType") 
                ? "Object" 
                : arrayIndex != null
                    ? arrayName + "_" + arrayIndex
                    : name;
        }

        element = XmlConvert.EncodeName(element);
        var ret = new XElement(element);

        if (input != null) {
            var type = input.GetType();
            var props = type.GetProperties();

            var elements = props.Select(p => {
                var pType = Nullable.GetUnderlyingType(p.PropertyType) ?? p.PropertyType;
                var name = XmlConvert.EncodeName(p.Name);
                var val = pType.IsArray ? "array" : p.GetValue(input, null);
                var value = pType.IsArray 
                    ? GetArrayElement(p, (Array)p.GetValue(input, null))
                    : pType.IsSimpleType() || pType.IsEnum 
                        ? new XElement(name, val) 
                        : val.ToXml(name);
                return value;
            })
            .Where(v=>v !=null);

            ret.Add(elements);
        }

        return ret;
    }

    #region helpers
    /// <summary>
    /// Gets the array element.
    /// </summary>
    /// <param name="info">The property info.</param>
    /// <param name="input">The input object.</param>
    /// <returns>Returns an XElement with the array collection as child elements.</returns>
    private static XElement GetArrayElement(PropertyInfo info, Array input) {
        var name = XmlConvert.EncodeName(info.Name);

        XElement rootElement = new XElement(name);

        var arrayCount = input == null ? 0 : input.GetLength(0);

        for (int i = 0; i < arrayCount; i++) {
            var val = input.GetValue(i);
            XElement childElement = val.GetType().IsSimpleType() ? new XElement(name + "_" + i, val) : _ToXml(val, null, i, name);

            rootElement.Add(childElement);
        }

        return rootElement;
    }

    #region .IsSimpleType
    public static bool IsSimpleType(this Type type) {
        return type.IsPrimitive || WriteTypes.Contains(type);
    }
    #endregion .IsSimpleType

    #endregion helpers
    #endregion .ToXml
}