ios-samples/LazyTableImages/RssParser.cs

//
// RssParser.cs
//
// Author:
//       Alan McGovern <alan@xamarin.com>
//
// Copyright 2011, Xamarin Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using System;
using System.Linq;
using System.Xml.Linq;
using System.Collections.Generic;

namespace LazyTableImages
{

    public static class RssParser
    {

        // These are used to select the correct nodes and attributes from the Rss feed
        static readonly XName FeedElement = XName.Get("feed", "http://www.w3.org/2005/Atom");
        static readonly XName EntryElement = XName.Get("entry", "http://www.w3.org/2005/Atom");
        static readonly XName AppUrlElement = XName.Get("id", "http://www.w3.org/2005/Atom");

        static readonly XName AppNameElement = XName.Get("name", "https://rss.itunes.apple.com");
        static readonly XName ArtistElement = XName.Get("artist", "https://rss.itunes.apple.com");
        static readonly XName ImageUrlElement = XName.Get("image", "https://rss.itunes.apple.com");

        static readonly XName HeightAttribute = XName.Get("height", "");

        public static List<App> Parse(string xml)
        {
            // Open the xml
            var doc = XDocument.Parse(xml);

            // We want to convert all the raw Xml nodes called 'entry' which
            // are in that namespace into instances of the 'App' class so they
            // can be displayed easily in the table.
            return doc.Element(FeedElement) // Select the 'feed' node.
                .Elements(EntryElement)     // Select all children with the name 'entry'.
                .Select(XmlElementToApp)    // Convert the 'entry' nodes to instances of the App class.
                .ToList();                  // Return as a List<App>.
        }

        static App XmlElementToApp(XElement entry)
        {
            // Select an image node
            var imageUrlNode = entry.Elements(ImageUrlElement).FirstOrDefault();

            // Parse the rest of the apps information from the XElement and
            // return the App instance.
            return new App
            {
                Name = entry.Element(AppNameElement).Value,
                Url = new Uri(entry.Element(AppUrlElement).Value),
                Artist = entry.Element(ArtistElement).Value,
                ImageUrl = new Uri(imageUrlNode.Value)
            };
        }
    }
}