define_type(
	'rss2',
	-description='Extends [xml_tree] specifically for the RSS2 format.'
);
	local('data' = xml_tree);

	define_tag(
		'onCreate',
		-req='title',
		-req='link',
		-req='description',
		-opt='language',
		-opt='copyright',
		-opt='managingEditor',
		-opt='webMaster',
		-opt='pubDate', -type='date',
		-opt='lastBuildDate', -type='date',
		-opt='category',
		-opt='generator',
		-opt='docs',
		-opt='cloud', -type='map',
		-opt='ttl', -type='integer',
		-opt='image', -type='map', -copy,
		-opt='rating',
		-opt='textInput', -type='map',
		-opt='skipHours', -type='array',
		-opt='skipDays', -type='array',		
		-opt='items'
	);
		self->'data'->setname('rss');
		self->'data'->addattribute('version'='2.0');
		self->'data'->addnamespace('atom'='http://www.w3.org/2005/Atom');
		self->'data'->newchild('channel');
		
		self->'data'->channel->newchild('atom:link');
		self->'data'->channel->getnode('atom:link')->addattribute('rel'='self');
		self->'data'->channel->getnode('atom:link')->addattribute('type'='application/rss+xml');
		self->'data'->channel->getnode('atom:link')->addattribute('href'=#link);
		
		// validation & defaults
		fail_if(
			!valid_url(#link),
			-1, 'The "link" element must be a valid URL.'
		);
		
		fail_if(
			local_defined('docs') && !valid_url(#docs),
			-1, 'The "docs" element must be a valid URL.'
		);
		
		if(local_defined('image'));
			local('reqd') = (: 'url', 'title', 'link');
			local('missing') = array;
			
			iterate(#reqd, local('i'));
				!#image->find(#i) || #image->find(#i) == '' ? #missing->insert(#i);
			/iterate;
			
			fail_if(
				#missing->size,
				-1, 'The "image" element is missing the following required values: ' + #missing->join(',') + '.'
			);
		
			fail_if(
				!valid_url(#image->find('url')),
				-1, 'The image URL provided is not valid.'
			);
			
			fail_if(
				(: 'gif', 'jpeg', 'jpg', 'png') !>> #image->find('url')->trim&split('.')->last,
				-1, 'The image URL does not point to a GIF, JPEG, or PNG image.'
			);
			
			if(integer(#image->find('width')));
				integer(#image->find('width')) > 144 ? #image->find('width') = 144;
			else;
				#image->insert('width' = 88);
			/if;

			if(integer(#image->find('height')));
				integer(#image->find('height')) > 400 ? #image->find('height') = 400;
			else;
				#image->insert('height' = 31);
			/if;
		/if;
		
		if(local_defined('textInput'));
			local('reqd') = (: 'title', 'description', 'name', 'link');

			local('missing') = array;
			
			iterate(#reqd, local('i'));
				!#textInput->find(#i) || #textInput->find(#i) == '' ? #missing->insert(#i);
			/iterate;
			
			fail_if(
				#missing->size,
				-1, 'The "textInput" element is missing the following required values: ' + #missing->join(',') + '.'
			);
			
			fail_if(
				!valid_url(#textInput->find('link')),
				-1, 'The URL value of the "textInput" element is not valid.'
			);
		/if;
		
		if(local_defined('skipHours'));
			fail_if(
				#skipHours->size > 24,
				-1, 'The "skipHours" element may not contain more than 24 items.'
			);
		
			iterate(#skipHours, local('i'));
				!#i->isa('integer') || #i < 0 || #i > 23 ? fail( -1, 'The "skipHours" element contains invalid values.');
			/iterate;
		/if;

		if(local_defined('skipDays'));
			fail_if(
				#skipDays->size > 7,
				-1, 'The "skipDays" element may not contain more than 7 items.'
			);
		
			local('days') = array(
				'Monday',
				'Tuesday',
				'Wednesday',
				'Thursday',
				'Friday',
				'Saturday',
				'Sunday'
			);
		
			iterate(#skipDays, local('i'));
				#days !>> #i ? fail( -1, 'The "skipDays" element contains invalid values.');
			/iterate;
		/if;
		
		// handle simple nodes for the channel
		local('simpleNodes') = array(
			'title',
			'link',
			'description',
			'language',
			'copyright',
			'managingEditor',
			'webMaster',
			'generator',
			'docs',
			'rating',
			'ttl'
		);
		
		iterate(#simpleNodes, local('i'));
			if(local_defined(#i));
				self->'data'->channel->newchild(#i);
				self->'data'->channel->getnode(#i)->addcontent(local(#i));
			/if;
		/iterate;

		// all other nodes require special handling

		// date nodes (convert to GMT)
		iterate((: 'pubDate', 'lastBuildDate'), local('i'));
			if(local_defined(#i));
				self->'data'->channel->newchild(#i);
				// Wed, 15 Jun 2005 19:00:00 GMT
				self->'data'->channel->getnode(#i)->addcontent(date_localtogmt(local(#i))->format('%a, %d %b %Y %H:%M:%S GMT'));
			/if;
		/iterate;

		// category
		if(local_defined('category'));
			self->'data'->channel->newchild('category');
			if(#category->isa('pair'));
				self->'data'->channel->category->addattribute('domain' = #category->first);
				self->'data'->channel->category->addcontent(#category->second);
			else;
				self->'data'->channel->category->addcontent(#category);
			/if;
		/if;
		
		// cloud
		if(local_defined('cloud'));
			self->'data'->channel->newchild('cloud');
			
			iterate(#cloud->keys, local('i'));
				self->'data'->channel->cloud->addattribute(#i = #cloud->find(#i));
			/iterate;
		/if;

		// image
		if(local_defined('image'));
			self->'data'->channel->newchild('image');
			
			iterate(#image->keys, local('i'));
				self->'data'->channel->image->newchild(#i);
				self->'data'->channel->image->getnode(#i, -count=1)->addcontent(#image->find(#i));
			/iterate;
		/if;

		// textInput
		if(local_defined('textInput'));
			self->'data'->channel->newchild('textInput');
			
			iterate(#textInput->keys, local('i'));
				self->'data'->channel->textInput->newchild(#i);
				self->'data'->channel->textInput->getnode(#i, -count=1)->addcontent(#textInput->find(#i));
			/iterate;
		/if;

		// skipHours
		if(local_defined('skipHours'));
			self->'data'->channel->newchild('skipHours');
			
			iterate(#skipHours, local('i'));
				self->'data'->channel->skipHours->newchild('hour');
				self->'data'->channel->skipHours->hour(loop_count)->addcontent(#i);
			/iterate;
		/if;

		// skipDays
		if(local_defined('skipDays'));
			self->'data'->channel->newchild('skipDays');
			
			iterate(#skipDays, local('i'));
				self->'data'->channel->skipDays->newchild('day');
				self->'data'->channel->skipDays->day(loop_count)->addcontent(#i);
			/iterate;
		/if;

		// items			
		if(local_defined('items'));
			iterate(#items, local('i'));
				self->'data'->channel->addchild(xml(#i));
			/iterate;
		/if;
	/define_tag;
	
	define_tag('_unknownTag');
		return(self->'data'->tag_name);
	/define_tag;
	
	define_tag('onConvert');
		return(string(self->'data'));
	/define_tag;
/define_type;



define_type(
	'item',
	-namespace='rss2_',
	-description='Generates XML for an RSS2 item node.'
);
	local('data' = xml_tree);
	
	define_tag(
		'onCreate',
		-opt='title',
		-opt='link',
		-opt='description',
		-opt='author',
		-opt='category',
		-opt='comments',
		-opt='enclosure', -type='map',
		-opt='guid',
		-opt='pubDate', -type='date',
		-opt='source'
	);
		fail_if(
			!local_defined('title') && !local_defined('description'), -1,
			'Either "title" or "description" must be specified.'
		);
	
		local('urls') = (: 'link', 'comments', 'guid');
	
		iterate(#urls, local('i'));
			fail_if(
				local_defined(#i) && !valid_url(local(#i)),
				-1, 'The "' + #i + '" element is not a valid URL.'
			);
		/iterate;
		
		if(local_defined('enclosure'));
			local('reqd') = (: 'url', 'length', 'type');
			local('missing') = array;
			
			iterate(#reqd, local('i'));
				#enclosure->find(#i) == '' ? #missing->insert(#i);
			/iterate;
			
			fail_if(
				#missing->size,
				-1, 'The "enclosure" element is missing required values: ' + #missing->join(',') + '.'
			);
			
			fail_if(
				!valid_url(#enclosure->find('url')),
				-1, 'The enclosure URL is not valid.'
			);
		/if;
	
		self->'data'->setname('item');
		
		iterate((:'title', 'link', 'description', 'author', 'comments', 'guid'), local('i'));
			if(local_defined(#i));
				self->'data'->newchild(#i);
				self->'data'->getnode(#i)->addcontent(local(#i));
			/if;
		/iterate;

		// category
		if(local_defined('category'));
			self->'data'->newchild('category');
			
			if(#category->isa('pair')); 
				self->'data'->category->addattribute('domain' = #category->first);
				self->'data'->category->addcontent(#category->second);
			else;
				self->'data'->category->addcontent(#category);
			/if;
		/if;
		
		if(local_defined('pubDate'));
			self->'data'->newchild('pubDate');
			// Wed, 15 Jun 2005 19:00:00 GMT
			self->'data'->pubDate->addcontent(date_localtogmt(#pubDate)->format('%a, %d %b %Y %H:%M:%S GMT'));
		/if;
		
		if(local_defined('enclosure'));
			self->'data'->newchild('enclosure');
			self->'data'->enclosure->addattribute('url'=#enclosure->find('url'));
			self->'data'->enclosure->addattribute('length'=#enclosure->find('length'));
			self->'data'->enclosure->addattribute('type'=#enclosure->find('type'));
		/if;
		
		if(local_defined('source'));
			self->'data'->newchild('source');
			self->'data'->source->addattribute('url' = #source->first);
			self->'data'->source->addcontent(#source->second);
		/if;
		
		// convert to xml type when finished to work around inheritance bugs
		self->'data' = xml(self->'data');
	/define_tag;

	define_tag('_unknownTag');
		return(self->'data'->tag_name);
	/define_tag;
	
	define_tag('onConvert');
		return(string(self->'data'));
	/define_tag;
/define_type;