Yahoo Weather

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Yahoo Weather

I recently received an email from a reader who asked how to read the weather from a Yahoo feed. I’ve posted the code here in case it’s of any use to anyone else.

protected void Page_Load(object sender, EventArgs e)
{
    //GS - Clear all headers written already
    Response.Clear();

    //GS - Fetch the weather information
    string uri = 
        @"http://xml.weather.yahoo.com/forecastrss?p=UKXX0025&u=c";
    XPathDocument xpd = null;
    try
    {
        xpd = new XPathDocument(uri);
    }
    catch (XmlException xe)
    {
        Response.Write("The following xml error occurred: " +
            xe.Message);
        Response.End();
        return;
    }

    //GS - Create a navigator
    XPathNavigator xpn = xpd.CreateNavigator();

    //GS - Pull out the weather information from the xml
    string weather = "";
    try
    {
        XPathNavigator node =
            xpn.SelectSingleNode(@"/rss/channel/item/description");
        weather = HttpUtility.HtmlDecode(node.InnerXml);
    }
    catch (XPathException xpe)
    {
        Response.Write("The following XPath exception occurred: "
            + xpe.Message);
        Response.End();
        return;
    }

    //GS - Write out the weather information
    Response.Write("<html>");
    Response.Write("<body>");
    Response.Write(weather);
    Response.Write("</body>");
    Response.Write("</html>");
}

Tags: Yahoo, Weather, Asp.Net, C#

Print | posted on Wednesday, August 02, 2006 9:08 AM

Comments on this post

This is fantastic. It answers a lot of questions I had about pulling out single node information.

I've been playing with this and I'm stuck on getting node information that has more than one value. For example, "City" information is held in "yweather:location", but I can't seem to get that to work. I'm doing it this way:

[snip]
try
{
XPathNavigator node_city = xpn.SelectSingleNode(@"/rss/channel/yweather:location").GetAttribute(city.ToString());

city = HttpUtility.HtmlDecode(node_city.InnerXml);
}
[/snip]
Any suggestions?

Thanks for your help,

Ray

Left by Ray Morris on Aug 30, 2006 2:08 PM

#

Hello Ray,

The location tag is defined within the yweather namespace so you need to add a namespace manager and add it as the second parameter to the SelectSingleNode function call. Something like the following should work.


//GS - Create a navigator
XPathNavigator xpn = xpd.CreateNavigator();

//GS - Add the yweather namespace
XmlNamespaceManager nsm = new XmlNamespaceManager(xpn.NameTable);
nsm.AddNamespace("yweather", "http://xml.weather.yahoo.com/ns/rss/1.0");

//GS - Pull out the weather information from the xml
string weather = "";
try
{
    XPathNavigator node =
        xpn.SelectSingleNode(@"/rss/channel/yweather:location",nsm);
    weather = node.GetAttribute("city", String.Empty);
}
catch (XPathException xpe)
{
    Response.Write("The following XPath exception occurred: "
        + xpe.Message);
    Response.End();
    return;
}