/// <summary>
/// Makes a request against RSS Weather service and add update the layer's table
/// </summary>
/// <param name="zipCode"></param>
/// <param name="Lat"></param>
/// <param name="Lon"></param>
private void AddWeatherItem(long zipCode, double Lat, double Lon)
{
try
{
string cityName;
double lat, lon;
int temp;
string condition;
string desc;
string iconPath;
string day;
string date;
int low;
int high;
int iconCode;
int iconWidth = 52; //default values
int iconHeight = 52;
Bitmap bitmap = null;
DataRow dbr = m_table.Rows.Find(zipCode);
if (dbr != null)
{
// get the date
DateTime updateDate = Convert.ToDateTime(dbr[14]);
TimeSpan ts = DateTime.Now - updateDate;
// if the item had been updated in the past 15 minutes, simply bail out.
if (ts.TotalMinutes < 15)
return;
}
//the base URL for the service
string url = "http://xml.weather.yahoo.com/forecastrss?p=";
//the RegEx used to extract the icon path from the HTML tag
string regxQry = "(http://(\\\")?(.*?\\.gif))";
XmlTextReader reader = null;
XmlDocument doc;
XmlNode node;
try
{
//make the request and get the result back into XmlReader
reader = new XmlTextReader(url + zipCode.ToString());
}
catch(Exception ex)
{
System.Diagnostics.Trace.WriteLine(ex.Message);
return;
}
//load the XmlReader to an xml doc
doc = new XmlDocument();
doc.Load(reader);
//set an XmlNamespaceManager since we have to make explicit namespace searches
XmlNamespaceManager xmlnsManager = new System.Xml.XmlNamespaceManager(doc.NameTable);
//Add the namespaces used in the xml doc to the XmlNamespaceManager.
xmlnsManager.AddNamespace("yweather", "http://xml.weather.yahoo.com/ns/rss/1.0");
xmlnsManager.AddNamespace("geo", "http://www.w3.org/2003/01/geo/wgs84_pos#");
//make sure that the node exists
node = doc.DocumentElement.SelectSingleNode("/rss/channel/yweather:location/@city", xmlnsManager);
if(null == node)
return;
//get the cityname
cityName = doc.DocumentElement.SelectSingleNode("/rss/channel/yweather:location/@city", xmlnsManager).InnerXml;
if(Lat == 0.0 && Lon == 0.0)
{
//in case that the caller did not specify a coordinate, get the default coordinate from the service
lat = Convert.ToDouble(doc.DocumentElement.SelectSingleNode("/rss/channel/item/geo:lat", xmlnsManager).InnerXml);
lon = Convert.ToDouble(doc.DocumentElement.SelectSingleNode("/rss/channel/item/geo:long", xmlnsManager).InnerXml);
}
else
{
lat = Lat;
lon = Lon;
}
//extract the rest of the information from the RSS response
condition = doc.DocumentElement.SelectSingleNode("/rss/channel/item/yweather:condition/@text", xmlnsManager).InnerXml;
iconCode = Convert.ToInt32(doc.DocumentElement.SelectSingleNode("/rss/channel/item/yweather:condition/@code", xmlnsManager).InnerXml);
temp = Convert.ToInt32(doc.DocumentElement.SelectSingleNode("/rss/channel/item/yweather:condition/@temp", xmlnsManager).InnerXml);
desc = doc.DocumentElement.SelectSingleNode("/rss/channel/item/description").InnerXml;
day = doc.DocumentElement.SelectSingleNode("/rss/channel/item/yweather:forecast/@day", xmlnsManager).InnerXml;
date = doc.DocumentElement.SelectSingleNode("/rss/channel/item/yweather:forecast/@date", xmlnsManager).InnerXml;
low = Convert.ToInt32(doc.DocumentElement.SelectSingleNode("/rss/channel/item/yweather:forecast/@low", xmlnsManager).InnerXml);
high = Convert.ToInt32(doc.DocumentElement.SelectSingleNode("/rss/channel/item/yweather:forecast/@high", xmlnsManager).InnerXml);
//use regex in order to extract the icon name from the html script
Match m = Regex.Match(desc,regxQry);
if(m.Success)
{
iconPath = m.Value;
//add the icon ID to the symbology table
DataRow tr = m_symbolTable.Rows.Find(iconCode);
if(null == tr)
{
//get the icon from the website
bitmap = DownloadIcon(iconPath, out iconWidth, out iconHeight);
//create a new record
tr = m_symbolTable.NewRow();
tr[1] = iconCode;
tr[3] = iconWidth;
tr[4] = iconHeight;
tr[6] = bitmap;
//update the symbol table. The initialization of the symbol cannot take place in here, since
//this code gets executed on a background thread.
lock(m_symbolTable)
{
m_symbolTable.Rows.Add(tr);
}
}
else //get the icon's dimensions from the table
{
//get the icon's dimensions from the table
iconWidth = Convert.ToInt32(tr[3]);
iconHeight = Convert.ToInt32(tr[4]);
}
}
else
{
iconPath = "";
}
//test whether the record already exists in the layer's table.
if(null == dbr) //in case that the record does not exist
{
//create a new record
dbr = m_table.NewRow();
if (!m_table.Columns[0].AutoIncrement)
dbr[0] = Convert.ToInt32(DateTime.Now.Millisecond);
//add the item to the table
lock (m_table)
{
dbr[1] = zipCode;
dbr[2] = cityName;
dbr[3] = lat;
dbr[4] = lon;
dbr[5] = temp;
dbr[6] = condition;
dbr[7] = iconPath;
dbr[8] = iconCode;
dbr[9] = day;
dbr[10] = date;
dbr[11] = low;
dbr[12] = high;
dbr[13] = false;
dbr[14] = DateTime.Now;
m_table.Rows.Add(dbr);
}
}
else //in case that the record exists, just update it
{
//update the record
lock (m_table)
{
dbr[5] = temp;
dbr[6] = condition;
dbr[7] = iconPath;
dbr[8] = iconCode;
dbr[9] = day;
dbr[10] = date;
dbr[11] = low;
dbr[12] = high;
dbr[14] = DateTime.Now;
dbr.AcceptChanges();
}
}
base.m_bIsCompiledDirty = true;
//fire an event to notify the user that the item has been updated
if (OnWeatherItemAdded != null)
{
WeatherItemEventArgs weatherItemEventArgs = new WeatherItemEventArgs(Convert.ToInt32(dbr[0]), zipCode, lon, lat, iconWidth, iconHeight);
OnWeatherItemAdded(this, weatherItemEventArgs);
}
}
catch(Exception ex)
{
System.Diagnostics.Trace.WriteLine("AddWeatherItem: " + ex.Message);
}
}
private void RefreshWeatherItemInvoked(WeatherItemEventArgs weatherItemInfo)
{
ITransformation transform = m_activeView.ScreenDisplay.DisplayTransformation as ITransformation;
if (transform == null)
return;
double[] iconDimensions = new double[2];
iconDimensions[0] = (double)weatherItemInfo.IconWidth;
iconDimensions[1] = (double)weatherItemInfo.IconHeight;
double[] iconDimensionsMap = new double[2];
transform.TransformMeasuresFF(esriTransformDirection.esriTransformReverse, 1, ref iconDimensionsMap[0], ref iconDimensions[0]);
m_invalidateExtent.PutCoords(0, 0, iconDimensionsMap[0], iconDimensionsMap[0]);
m_point.PutCoords(weatherItemInfo.mapX, weatherItemInfo.mapY);
m_invalidateExtent.CenterAt(m_point);
m_activeView.PartialRefresh(esriViewDrawPhase.esriViewGeography, m_weatherLayer, m_invalidateExtent);
m_activeView.ScreenDisplay.UpdateWindow();
}
/// <summary>
/// weather layer ItemAdded event handler
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
/// <remarks>gets fired when an item is added to the table</remarks>
private void OnWeatherItemAdded(object sender, WeatherItemEventArgs args)
{
// use the invoke helper since this event gets fired on a different thread
m_invokeHelper.RefreshWeatherItem(args);
}
public void RefreshWeatherItem(WeatherItemEventArgs weatherItemInfo)
{
try
{
// Invoke the RefreshInternal through its delegate
if (!this.IsDisposed && this.IsHandleCreated)
Invoke(new RefreshWeatherItemHelper(RefreshWeatherItemInvoked), new object[] { weatherItemInfo });
}
catch (Exception ex)
{
System.Diagnostics.Trace.WriteLine(ex.Message);
}
}