Weather_Agent

Weather_Agent = Class.create({
	initialize: function(woeid) {
		this.woeid = woeid;
	},
	
	get: function(on_complete, on_error) {
		var resource = 'http://weather.yahooapis.com/forecastrss?u=c&w=' + this.woeid;
		
		new Ajax.Request(resource, {
			method: 'get',
			asynchronous: true,
			onSuccess: this.on_response.bind(this, on_complete),
			onFailure: this.on_error.bind(this)
		});
	},
	
	on_response: function(on_complete, transport) {
		if (transport.responseXML) {
			var response = transport.responseXML;
			on_complete(this.rss_to_object(response));
		}
	},
	
	rss_to_object: function(xml) {
		return {
			weather: this.rss_weather_to_object(xml),
			attribution: this.rss_image_to_object(xml)
		};
	},
	
	rss_weather_to_object: function(xml) {
		var d = xml.documentElement;
		
		var condition = d.querySelector('item condition');
		var forecast1 = d.querySelector('item forecast:first-of-type');
		var forecast2 = d.querySelector('item forecast:last-of-type');

		return {
			code: condition.getAttribute('code'),
			temp: condition.getAttribute('temp'),
			today: {
				code: forecast1.getAttribute('code'),
				high: forecast1.getAttribute('high'),
				low: forecast1.getAttribute('low')
			},
			tomorrow: {
				code: forecast2.getAttribute('code'),
				high: forecast2.getAttribute('high'),
				low: forecast2.getAttribute('low')
			}
		};
	},
	
	rss_image_to_object: function(xml) {
		var d = xml.documentElement;
		
		return {
			text: d.querySelector('image title').textContent,
			width: d.querySelector('image width').textContent,
			height: d.querySelector('image height').textContent,
			link: d.querySelector('image link').textContent,
			url: d.querySelector('image url').textContent
		};
	},
	
	on_error: function(error) {
		$.trace('error');
	}
});