/*
    Adobe Systems Incorporated(r) Source Code License Agreement
    Copyright(c) 2005 Adobe Systems Incorporated. All rights reserved.
    
    Please read this Source Code License Agreement carefully before using
    the source code.
    
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package com.adobe.xml.syndication.generic
{

    import com.adobe.xml.syndication.atom.Atom10;
    import com.adobe.xml.syndication.atom.Atom03;
    import com.adobe.xml.syndication.rss.RSS10;
    import com.adobe.xml.syndication.rss.RSS20;

    /**
     * The FeedFactory allows you to create generic IFeed objects from any
     * version of RSS or Atom. You can then access data within the feed
     * without knowing what type of feed or which version it is. For most
     * people, this will be the starting point for the XML syndication
     * project.
     * 
     * @langversion ActionScript 3.0
     * @playerversion Flash 8.5
     * @tiptext
     */
    public class FeedFactory
    {
        /**
         * Allows you to get a generic IFeed object from a string of XML. The
         * string can be any version of RSS or Atom.
         *
         * @param xmlStr A string of XML that is any type of RSS or Atom.
         * @return A generic IFeed object that lets you access data in the
         *         feed without having to know what kind of feed it is.
         * @throws UnknownFeedError If it can't determine what kind of feed
         *         you passed in.
         *
         * @langversion ActionScript 3.0
         * @playerversion Flash 8.5
         * @tiptext
         */
        public static function getFeedByString(xmlStr:String):IFeed
        {
            return FeedFactory.getFeedByXML(new XML(xmlStr));
        }

        /**
         * Allows you to get a generic IFeed object from an XML object. The
         * XML can represent any version of RSS or Atom.
         *
         * @param x An XML object that represents any type of RSS or Atom.
         * @return A generic IFeed object that lets you access data in the
         *         feed without having to know what kind of feed it is.
         * @throws UnknownFeedError If it can't determine what kind of feed
         *         you passed in.
         *
         * @langversion ActionScript 3.0
         * @playerversion Flash 8.5
         * @tiptext
         */
        public static function getFeedByXML(x:XML):IFeed
        {
            // Atom 0.3
            if (x.namespace().uri.toLowerCase() == "http://purl.org/atom/ns#")
            {
                var atom03:Atom03 = new Atom03();
                atom03.populate(x);
                return new Atom03Feed(atom03);
            }

            // Atom 1.0
            if (x.namespace().uri.toLowerCase() == "http://www.w3.org/2005/atom")
            {
                var atom10:Atom10 = new Atom10();
                atom10.populate(x);
                return new Atom10Feed(atom10);
            }

            // RSS 1.0
            var namespaces:Array = x.namespaceDeclarations();
            for (var i:uint = 0; i < namespaces.length; ++i)
            {
                if (namespaces[i].uri.toLowerCase() == "http://purl.org/rss/1.0/")
                {
                    var rss10:RSS10 = new RSS10();
                    rss10.populate(x);
                    return new RSS10Feed(rss10);
                }
            }

            // RSS .91, .92, 2.0
            if (x.name() == "rss" && Number(x.@version) <= 2)
            {
                var rss20:RSS20 = new RSS20();
                rss20.populate(x);
                return new RSS20Feed(rss20);
            }
            
            // Don't recognize this feed.  Throw an exception.
            throw new UnknownFeedError("Unable to determine feed type.");
        }
    }
}