RssDocument.cs

using System;
using System.Collections.Generic;
using System.Xml;
using Waher.Content.Xml;
using Waher.Runtime.Inventory;
 
namespace Waher.Content.Rss
{
    public class RssDocument
    {
        private readonly XmlDocument xml;
 
        public RssDocument(XmlDocument Xml, Uri BaseUri)
        {
            if (Xml is null)
                throw new ArgumentNullException(nameof(Xml));
 
            if (Xml.DocumentElement is null)
                throw new ArgumentException("Missing XML.", nameof(Xml));
 
            if (Xml.DocumentElement.LocalName != "rss")
                throw new ArgumentException("Not an RSS document.", nameof(Xml));
 
            this.xml = Xml;
            this.Version = XML.Attribute(Xml.DocumentElement, "version", 0.0);
 
            List<RssChannel> Channels = new List<RssChannel>();
            List<RssWarning> Warnings = new List<RssWarning>();
            List<IRssExtension> Extensions = new List<IRssExtension>();
 
            foreach (XmlNode N in Xml.DocumentElement.ChildNodes)
            {
                if (!(N is XmlElement E))
                    continue;
 
                if (E.NamespaceURI == Xml.NamespaceURI)
                {
                    switch (E.LocalName)
                    {
                        case "channel":
                            RssChannel Channel = new RssChannel(E, BaseUri);
                            Channels.Add(Channel);
                            Warnings.AddRange(Channel.Warnings);
                            break;
 
                        default:
                            Warnings.Add(new RssWarning(E));
                            break;
                    }
                }
                else
                {
                    IRssExtension Extension = Types.FindBest<IRssExtension, XmlElement>(E);
                    if (Extension is null)
                        Warnings.Add(new RssWarning(E));
                    else
                        Extensions.Add(Extension.Create(E, BaseUri));
                }
            }
 
            this.Channels = Channels.ToArray();
            this.Warnings = Warnings.ToArray();
            this.Extensions = Extensions.ToArray();
        }
 
        public XmlDocument Xml => this.xml;
 
        public double Version { get; }
 
        public RssChannel[] Channels { get; }
 
        public RssWarning[] Warnings { get; }
 
        public IRssExtension[] Extensions { get; } = null;
    }
}