Linq to XML Can't get Query Working

EDN Admin · Jun 27, 2012

Im trying to query the xml results passed back from the NOOA Weather webservice. For this example, Im trying to get the "hourly" weather value
Call:
<pre class="prettyprint string xml = localWeather.NDFDgen(lat, lng, NOAAWeather.productType.timeseries, DateTime.Now,
DateTime.Now, NOAAWeather.unitType.e, wtp);
XElement curXML = XElement.Parse(xml);[/code]
 

Trimmed down version of whats returned:
<pre class="prettyprint dwml version="1.0" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://graphical.weather.gov/xml/DWMLgen/schema/DWML.xsd
<head>
<product srsName="WGS 1984" concise-name="time-series" operational-mode="official
<title>NOAAs National Weather Service Real Time Mesoscale Analysis And Forecast Data</title>
<field>meteorological</field>
<category>analysis and forecast</category>
<creation-date refresh-frequency="PT1H 2012-06-27T15:47:23Z</creation-date>
</product>
<source>
<more-information>http://products.weather.gov/search.php</more-information>
<production-center>Meteorological Development Laboratory<sub-center>Product Generation Branch</sub-center></production-center>
<disclaimer>http://www.nws.noaa.gov/disclaimer.html</disclaimer>
<credit>http://www.weather.gov/</credit>
<credit-logo>http://www.weather.gov/images/xml_logo.gif</credit-logo>
<feedback>http://www.weather.gov/feedback.php</feedback>
</source>
</head>
<data>
<location>
<location-key>point1</location-key>
<point latitude="43.63" longitude="-89.78" />
</location>
<moreWeatherInformation applicable-location="point1 http://forecast.weather.gov/MapClick.php?textField1=43.63&textField2=-89.78</moreWeatherInformation>
<time-layout time-coordinate="local" summarization="none
<layout-key>k-p24h-n1-8</layout-key>
<start-valid-time>2012-06-27T07:00:00-05:00</start-valid-time>
<end-valid-time>2012-06-28T07:00:00-05:00</end-valid-time>
</time-layout>
<parameters applicable-location="point1
<temperature type="maximum" units="Fahrenheit" time-layout="k-p24h-n1-1
<name>Daily Maximum Temperature</name>
<value>95</value>
</temperature>
<temperature type="hourly" units="Fahrenheit" time-layout="k-p3h-n1-3
<name>Temperature</name>
<value>90</value>
</temperature>
<cloud-amount type="total" units="percent" time-layout="k-p3h-n1-3
<name>Cloud Cover Amount</name>
<value>14</value>
</cloud-amount>
</parameters>
</data>
</dwml>[/code]
Ideally, I would like to write a query that gets the "name" and "value" child elements based on the parent elements "type" attribute. For example I want to return "Temperature" and "90" accordingly :
<temperature type="hourly" units="Fahrenheit" time-layout="k-p3h-n1-3 
<name>Temperature</name> 
<value>90</value> 
</temperature>
Ive tried getting at these values a couple of ways:
First attempt:
<pre class="prettyprint var temps =
from item in curXML.Descendants("temperature")
select item;

foreach (var temp in temps)
{
switch (temp.Attribute("type").Value)
{
case "hourly":
var curTemp = temp.Value - returns "temperature 90" which is wrong, just want the 90
var curTemp = temp.Element("Value") - doesnt work
break;
}
}[/code]
 
Next, Ive been trying to query for the specific element instead of doing a foreach, but not sure what Im doing:
<pre class="prettyprint string t = "hourly";
var v = from weather in curXML.Descendants("temperature")
where t == weather.Element("temperature").Attribute("type").Value
select weather.Elements - not sure what I should be selecting[/code]
 
Can someone give me some pointers? Thanks

<hr class="sig James

View the full article

Linq to XML Can't get Query Working

EDN Admin

Well-known member

Similar threads