I'm trying to find the inner text value of an element using LINQ-to-XML (an XElement object). I make my service call and get an XML response back that I've successfully loaded into an XElement object. I want to extract the inner text of one of the elements - however, every time I try to do this, I get a null result.
I feel like I'm missing something super-simple, but I'm fairly new to LINQ-to-XML. Any help is appreciated.
I'm trying to get the inner text value of the StatusInfo/Status element. Here's my XML document that's returned:
<feed xml:lang="en-us" xmlns="http://www.w3.org/2005/Atom">
<title type="text">My Response</title>
<id>tag:foo.com,2012:/bar/06468dfc-32f7-4650-b765-608f2b852f22</id>
<author>
<name>My Web Services</name>
</author>
<link rel="self" type="application/atom+xml" href="http://myServer/service.svc/myPath" />
<generator uri="http://myServer" version="1">My Web Services</generator>
<entry>
<id>tag:foo.com,2012:/my-web-services</id>
<title type="text" />
<updated>2012-06-27T14:22:42Z</updated>
<category term="tag:foo.com,2008/my/schemas#system" scheme="tag:foo.com,2008/my/schemas#type" />
<content type="application/vnd.my.webservices+xml">
<StatusInfo xmlns="tag:foo.com,2008:/my/data">
<Status>Available</Status> <!-- I want the inner text -->
</StatusInfo>
</content>
</entry>
</feed>
Here's a snippet of code that I'm using to extract the value (which doesn't work):
XElement root = XElement.Load(responseReader);
XNamespace tag = "tag:foo.com,2008:/my/data";
var status = (from s in root.Elements(tag + "Status")
select s).FirstOrDefault();
My status variable is always null. I've tried several variations on this, but to no avail. The part that's confusing me is the namespace -- tag and 2008 are defined. I don't know if I'm handling this correctly or if there's a better way to deal with this.
Also, I don't have control over the XML schema or the structure of the XML. The service I'm using is out of my control.
Thanks for any help!
Try Descendants() instead of Elements():
XElement x = XElement.Load(responseReader);
XNamespace ns = "tag:foo.com,2008:/my/data";
var status = x.Descendants(ns + "Status").FirstOrDefault().Value;
There are 2 Namespaces in the feed:
the Atom namespace
the tag namespace
The outer xml needs to use the Atom namespace, while a portion of the inner xml needs to use the tag namespace. i.e.,
var doc = XDocument.Load(responseReader);
XNamespace nsAtom = "http://www.w3.org/2005/Atom";
XNamespace nsTag = "tag:foo.com,2008:/my/data";
// get all entry nodes / use the atom namespace
var entry = doc.Root.Elements(nsAtom + "entry");
// get all StatusInfo elements / use the atom namespace
var statusInfo = entry.Descendants(nsTag + "StatusInfo");
// get all Status / use the tag namespace
var status = statusInfo.Elements(nsTag + "Status");
// get value of all Status
var values = status.Select(x => x.Value.ToString()).ToList();
Related
I am trying to read the values of the elements present in XML. It is working properly if input doesn't contains any namespaces related attributes in that XML as below -
string testInputXML = #"
<FIXML>
<Header>
<RequestHeader>
<MessageKey>
<RequestUUID>Req_1499940064961</RequestUUID>
<ServiceRequestId>getLastNTransactionsWithPagination</ServiceRequestId>
<ServiceRequestVersion>10.2</ServiceRequestVersion>
<ChannelId>COR</ChannelId>
<LanguageId></LanguageId>
</MessageKey>
</RequestHeader>
</Header>
<isLogging>true</isLogging>
</FIXML>
";
XElement myElement = XElement.Parse(testInputXML);
Console.WriteLine(myElement.Element("isLogging").Value);
If input XML contains any namespaces related attributes then it is throwing exception.
Object reference not set to an instance of an object.
string testInputXML = #"
<FIXML xsi:schemaLocation=""http://www.w3.org/2001/XMLSchema-instance"" xmlns=""http://www.w3.org/fixml"" xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"">
<Header>
<RequestHeader>
<MessageKey>
<RequestUUID>Req_1499940064961</RequestUUID>
<ServiceRequestId>getLastNTransactionsWithPagination</ServiceRequestId>
<ServiceRequestVersion>10.2</ServiceRequestVersion>
<ChannelId>COR</ChannelId>
<LanguageId></LanguageId>
</MessageKey>
</RequestHeader>
</Header>
<isLogging>true</isLogging>
</FIXML>
";
XElement myElement = XElement.Parse(testInputXML);
Console.WriteLine(myElement.Element("isLogging").Value);
Is there any way to exclude the namespaces present in the XML while fetching element values?
Try this:
Console.WriteLine(myElement.DescendantsAndSelf().Elements().FirstOrDefault(d => d.Name.LocalName == "isLogging")?.Value);
Try using XPath like this:
XDocument xmlDoc = XDocument.Parse(xml);
XElement element = xmlDoc.XPathSelectElement("/*[name()='FIXML']/*[name()='isLogging']");
I have the following XML
<ABC xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://ns.hr-xml.org/2007-04-15">
<ReceiptId>
<IdValue>123</IdValue>
</ReceiptId>
<ClientOrderId>
<IdValue>345</IdValue>
</ClientOrderId>
<AccessPoint>
<Description>My Description</Description>
</AccessPoint>
<ABCStatus>
<Status>Error</Status>
<Details>ERRORS:
Talent is already in an active process for this opening.
</Details>
<StatusDate>2015-08-05</StatusDate>
</ABCStatus>
</ABC>
I am trying to retrieve the element value 345 nested in IdValue and ClientOrderId
I have used the Linq to xml code in C# to retrieve the value with no luck
XDocument XMLResults = XDocument.Parse(sResult);
var sClientOrderID =
from nodeAElem in XMLResults.Root.Elements("ABC")
from nodeA1Elem in nodeAElem.Elements("ClientOrderId")
from nodeA11Elem in nodeA1Elem.Elements("IdValue")
select nodeA11Elem.Value;
also need to retrieve the Status Elements value which is Error for the above xml.
Any help is greatly appreciated
Your XML document is using a namespace, you have to use it in your query to make it work.
Root already brings you to ABC element, so you don't have to call Elements("ABC")
You're looking for single value, so you probably want to use Element instead of Elements.
var ns = (XNamespace)"http://ns.hr-xml.org/2007-04-15";
var sClientOrderID = (int)XMLResults.Root
.Element(ns + "ClientOrderId")
.Element(ns + "IdValue");
I use C#. Please consider following XML:
<item>
<title>lorem</title>
<description>ipsum</description>
<media:category>Sports</media:category>
<media:title>Combo</media:title>
<media:thumbnail url='http://dolor/0.jpg' height='100' width='200'/>
<media:thumbnail url='http://sit/0.jpg' height='300' width='400'/>
</item>
I would like to be able to retrieve a List of all elements that have namespace eg. media.
The XML is loaded into XElement. I am able to find elements using Linq by name, eg. thumbnail, but not by namespace.
This is not always a valid XML, because xmlns namespace is not always declared. It is loaded to XElement this way:
XElement _root = XDocument.Parse(xmlString).Root;
You can try using this XPath expression to select all element in specific namespace :
//*[namespace-uri()='http://uri-address-here']
For example in C# :
var xml = #"<item xmlns:media='http://www.foo.org/'>
<title>lorem</title>
<description>ipsum</description>
<media:category>Sports</media:category>
<media:title>Combo</media:title>
<media:thumbnail url='http://dolor/0.jpg' height='100' width='200'/>
<media:thumbnail url='http://sit/0.jpg' height='300' width='400'/>
</item>";
var element = XElement.Parse(xml);
var elements = element.XPathSelectElements("//*[namespace-uri()='http://www.foo.org/']");
This is the sample xml of a feed item
<item>
<pubDate>2013-12-11 10:28:55</pubDate>
<title>
SAG Awards Nominations: 12 Years a Slave, Breaking Bad lead the race
</title>
<link>
http://www.rottentomatoes.com/m/1929182/news/1929182/
</link>
<description>
<![CDATA[ ]]>
</description>
<atom:link rel="thumbnail" type="image/*" href="http://content6.flixster.com/movie/11/17/36/11173600_tmb.jpg"/>
</item>
c# code for parsing xml elements
List<XElement> elementsList = xmlItems.Descendants("item").ToList();
foreach (XElement rssItem in elementsList)
{
RSSItem rss = new RSSItem();
rss.Description1 = rssItem.Element("description").Value;
rss.Link1 = rssItem.Element("link").Value;
rss.Title1 = rssItem.Element("title").Value;
rss.ImageUrl= ;
}
I successfully parsed the xml elements except the atom:link tag url.
How we can parse the href property from the atom:link tag ?
Link has a namespace, you need to indicate it when parsing the XML. I don't remember exactly what namespace atom is, but it should be indicated somewhere in the XML file (usually on the root node). For instance, if it is:
<feed xmlns:atom="http://www.w3.org/2005/Atom">
Then you need to parse it like this:
rss.Link1 = (string)rssItem.Element(XName.Get("link", "http://www.w3.org/2005/Atom")).Attribute("href");
You need to specify the namespace when you look for the element:
XNamespace atom = "http://www.w3.org/2005/Atom";
...
rss.Link1 = rssItem.Element(atom + "link").Attribute("href").Value;
LINQ to XML makes namespace handling much simpler than any other XML API I've seen, but you still need to be aware of it. (I'm surprised the other elements aren't in a namespace, to be honest.)
I'd also transform your foreach loop into a LINQ query:
var items = xmlItems.Descendants("item")
.Select(x => new RSSItem {
Description1 = x.Element("description").Value,
Link1 = x.Element(atom + "link").Attribute("href").Value,
Title1 = x.Element("title").Value,
...
})
.ToList();
Also consider using a cast to string instead of the Value property, if some of the elements may be missing - that will set the relevant property to null, instead of throwing a NullReferenceException.
EDIT: If the link element is missing, you can fix that with:
Link1 = (string) x.Elements(atom + "link").Attributes("href").FirstOrDefault()
That will find the first href attribute within an atom link element, or use null - and then the cast to string will just return null if there's no attribute. (That's part of the user-defined conversion from XAttribute to string.)
I have an xml file loaded into an XDocument that I need to extract a value from, and I'm not sure of the best way to do it. Most of the things I'm coming up with seem to be overkill or don't make good use of xml rules. I have the following snippet of xml:
<entry>
<observation classCode="OBS" moodCode="EVN">
<templateId root="2.16.840.1.113883.10.20.6.2.12" />
<code code="121070" codeSystem="1.2.840.10008.2.16.4" codeSystemName="DCM" displayName="Findings">
</code>
<value xsi:type="ED">
<reference value="#121071">
</reference>
</value>
</observation>
</entry>
There can be any number of <entry> nodes, and they will all follow a similar pattern. The value under the root attribute on the templateId element contains a known UID that identifies this entry as the one I want. I need to get the reference value.
My thought is to find the correct templateID node, back out to the observation node, find <valuexsi:type="ED"> and then get the reference value. This seems overly complex, and I am wondering if there is another way to do this?
EDIT
The xml I receive can sometimes have xml nested under the same node name. In other words, <observation> may be located under another node named <observation>.
You have problems, because your document uses Namespaces, and your query is missing them.
First of all, you have to find xsi namespace declaration somewhere in your XML (probably in the most top element).
It will look like that:
xmlns:xsi="http://test.namespace"
The, take the namespace Uri and create XNamespace instance according to it's value:
var xsi = XNamespace.Get("http://test.namespace");
And use that xsi variable within your query:
var query = from o in xdoc.Root.Element("entries").Elements("entry").Elements("observation")
let tId = o.Element("templateId")
where tId != null && (string)tId.Attribute("root") == "2.16.840.1.113883.10.20.6.2.12"
let v = o.Element("value")
where v != null && (string)v.Attribute(xsi + "type") != null
let r = v.Element("reference")
where r != null
select (string)r.Attribute("value");
var result = query.FirstOrDefault();
I have tested it for following XML structure:
<root xmlns:xsi="http://test.namespace">
<entries>
<entry>
<observation classCode="OBS" moodCode="EVN">
<templateId root="2.16.840.1.113883.10.20.6.2.12" />
<code code="121070" codeSystem="1.2.840.10008.2.16.4" codeSystemName="DCM" displayName="Findings">
</code>
<value xsi:type="ED">
<reference value="#121071">
</reference>
</value>
</observation>
</entry>
</entries>
</root>
The query returns #121071 for it.
For your input XML you will probably have to change first line of query:
from o in xdoc.Root.Element("entries").Elements("entry").Elements("observation")
to match <observation> elements from your XML structure.
Would something along the lines of the following help?
XDocument xdoc = GetYourDocumentHere();
var obsvlookfor =
xdoc.Root.Descendants("observation")
.SingleOrDefault(el =>
el.Element("templateId")
.Attribute("root").Value == "root value to look for");
if (obsvlookfor != null)
{
var reference = obsvlookfor
.Element("value")
.Element("reference").Attribute("value").Value;
}
My thought is as follows:
Pull out all the observation elements in the document
Find the only one (or null) where the observation's templateId element has a root attribute you're looking for
If you find that observation element, pull out the value attribute against the reference element which is under the value element.
You might have to include the Namespace in your LINQ. To retrieve that you would do something like this:
XNamespace ns = xdoc.Root.GetDefaultNamespace();
Then in your linq:
var obsvlookfor = xdoc.Root.Descendants(ns + "observation")
I know I had some issues retrieving data once without this. Not saying its the issue just something to keep in mind particularly if your XML file is very in depth.