I have done the below many times using a xmlDocument approach, but I wanted to use the more powerful linq to xml approach.
However, I seem to have run into a wall.
I am getting data back from a restful API from twillio / crmText.
Here is a link to their site where their docs live:
http://crmtext.com/api/docs
Here is my XML string:
<response op="getcustomerinfo" status="200" message="ok" version="1.0">
<customer>
<totalMsg>3</totalMsg>
<custId>9008281</custId>
<custName></custName>
<timestamp>2015-04-30 16:17:19</timestamp>
<optinStatus>3</optinStatus>
<custMobile>6185551212</custMobile>
<subacct>1st Choice Courier</subacct>
</customer>
</response>
I need to find out the optinStatus. It should return 3.
I am using the below, which return the above xml
XDocument xdoc = XDocument.Parse(result1);
I have tried about 4000 different things, including:
IEnumerable<XElement> otinStatus = from el in xdoc.Elements("customer") select el;
IEnumerable<XElement> otinStatus2 = from el in xdoc.Elements("cusotmer.optinStatus") select el;
IEnumerable<XElement> otinStatus3 = from el in xdoc.Elements("optinStatus") select el;
All of which returns no results.
Please help, I know this is something simple I am missing.
Thank you in advance -- Joe
Retrieve an Element's Value
var status = xDoc
.Descendants("optinStatus") // get the optinStatus element
.Single() // we're expecting a single result
.Value; // get the XElement's value
Example
Here is a working Fiddle for you. You can see it running live here. The output is 3.
using System;
using System.Linq;
using System.Xml;
using System.Xml.Linq;
public class Program
{
public static void Main()
{
var xDoc = XDocument.Parse(xmlString);
var status = xDoc.Descendants("optinStatus").Single();
Console.WriteLine(status.Value);
}
private static string xmlString = #"
<response op=""getcustomerinfo"" status=""200"" message=""ok"" version=""1.0"">
<customer>
<totalMsg>3</totalMsg>
<custId>9008281</custId>
<custName></custName>
<timestamp>2015-04-30 16:17:19</timestamp>
<optinStatus>3</optinStatus>
<custMobile>6185312349</custMobile>
<subacct>1st Choice Courier</subacct>
</customer>
</response>
";
}
Explanation
Descendents() is an instance axes method (or just axes in shorthand). It returns an IEnumerable<XElement> of all matching descendents. On its results, we call Single(). It is a Linq method that returns the only element of a sequence. If there is more than one element, it throws an error. We're left with a single XElement. This represent an entire XML element. Since we only want its value not the entire element, we call the Value property. Bingo, we're done.
A Bit More Detail
Axes come in two kinds:
Instance axes methods, which MSDN lists here, are invokable members of the XElement, XDocument, and XNode classes.
Extension axes methods, which MSDN lists here, are invokable on collections.
With one exception, an axes method returns a collection of type IEnumerable<T>. The exception is Element(), which returns the first matching child object. That what AmatuerDev used and, as in your question, if you are only expecting a single result, it is a just as good if not better approach that is Descendants().
Retrieve an Attribute Value
Once we have an XElement, we can retrieve one of its attributes instead of its value. We do that by calling the Attributes() method. It returns the matching XAttribute. Since we only want the attribute value, we call the Value property. Voila.
// for attribute
var response = xDoc.Descendants("response").Single();
var attr = response.Attribute("status");
General Approach
Using Linq to XML is a two step process.
Call an axes method to obtain an IEnumerable<T> result.
Use Linq to query that.
See Also
Here is some relevant MSDN documentation:
How to: Retrieve the Value of an Element (LINQ to XML)
LINQ to XML Axes
Assuming xDoc being the XDocument. Have you tried..
var customer = xDoc.Root.Element("customer");
var optinStatus = customer.Element("optinStatus");
var optinStatusValue = optinStatus.Value;
Related
I have the following XML structure:
<init_deinit>
<step name="init">
<call>...</call>
<check>...</check>
<call>...</call>
<wait>...</wait>
....
</step>
<step name="deinit">
....
</step>
</init_deinit>
There is a lot of examples of how to retrieve all descendants of a single type. I.E.:
XDocument xdoc = XDocument.Load("file.xml")
var all_call_tags = xdoc.Descendants("init_deinit").Elements("step").ElementAt(0).Elements("call");
But I need to retrieve ALL the children of the 'step' element and I need to retrieve them in the exact order thay are written in the XML. So what I need is something like IEnumerable iterator that contains XElements call, check, call and wait in this order. I tried but failed so far :)
Thank you for your advice!
This will give you all Descendants of step elements:
xdoc.Descendants("step").SelectMany(x => x.Descendants());
If you want Descendants of first step element use
xdoc.Descendants("step").First().Descendants();
Please try this :
XDocument xdoc = XDocument.Load("file.xml");
//Here you will get all the descendants of the first step
xdoc.Descendants("step").First().Descendants();
//To get all Descendants of step elements:
var x = xdoc.Descendants("step").Descendants();
I have an XML document that i have deserialized according to my model class, now i want to convert it into an IEnumerable<XmlDocument> or IEnumerable<string> which is the return type of my function so i could return valid XML reply from my MVC REST API.
XmlDocument xml = new XmlDocument();
xml.LoadXml(responseStream);
XmlSerializer x = new XmlSerializer(typeof(mSchoolModel));
mSchoolModel mgp = (mSchoolModel)x.Deserialize(responseObj.GetResponseStream());
//return xml;
So can anyone help me how can i convert this into an IEnumerable?
Use the LINQ-to-XML API.
Convert your XmlDocument instance to an XDocument instance. Instructions available at: http://blogs.msdn.com/b/xmlteam/archive/2009/03/31/converting-from-xmldocument-to-xdocument.aspx
Use the Elements() or Descendants() methods on the XDocument instance to get an IEnumerable<XElement>
Transform the IEnumerable<XElement> to an IEnumerable<string> using the LINQ Enumerable.Select() operator.
Here's a simple example:
IEnumerable<string> elements
= XDocument
.Load(new XmlNodeReader(xml))
.Elements()
.Select(element => element.ToString());
*Note: since a valid XML document can only have one root node, the resulting collection from the example above won't be very interesting, but you should have enough here to get what it is that you need. If you're familiar with XPath, you may find it easier to get the elements you want using the XPath extensions to LINQ to XML. See: How To: Query LINQ to XML Using XPath
Update
Realized I may have read your question wrong. If you have an XmlDocument instance and you need to return an IEnumerable<XmlDocument> all you have to do is wrap the instance in a collection. For example,
IEnumerable<XmlDocument> xmlCollection = new XmlDocument[]{ xml };
Of course, this approach can be used for wrapping any object into a singleton collection of objects of the same type.
This is driving me a little crazy. I am pulling an XML string from a database column and successfully creating an XDocument using XDocument.Parse. I've used linq to xml before to query xml trees but for some reason on this everything I am doing is returning null. Is it something to do with the namespace?
Here is a sampling of the text visualizer for my XDocument object:
// removed XML for privacy reasons
An example of the query I am trying:
XElement algorithmId = (from algoId in reportLogXml.Descendants(ALGORITHM_ID)
select algoId).FirstOrDefault();
I am using a constant for the string value and I have quadruple checked that the spelling matches as well as trying several different elements that are clearly in the document but they all return null. What am I doing wrong here?
Yes, it probably has to do with the namespace but also the <AlgorithmId> element has no descendants.
You can fix the ns problem like this:
//untested
XNameSpace ns0 = "http://schemas.datacontract.org/2004/07/Adapters.Adapter";
var ns1 = reportLogXml.Root.GetDefaultNamespace();
// check: ns0 and ns1 should be equal here
... in reportLogXml.Descendants(ns1 + ALGORITHM_ID)
Note that this is a special + operator, follow the format exactly.
I have XElement object which is my XML tree read from XML file. Now I want to check all the nodes in this tree to get first attribute name and value. Is there any simple way to go through all of the nodes (from root till leaves)? My XML file has got very many different and strange nodes - that's why it's harder to solve this issue. I thought about writing some recursion, but hope it's another way to solve that easier.
Maybe take a look to Xpath. an XPath like this //*[#id=42] could do the job.
It means get all nodes which have an attribute "id" of value 42.
You can do just //* which gonna returns all nodes in a tree.
Xpath :
http://msdn.microsoft.com/en-gb/library/ms950786.aspx
Syntax :
http://msdn.microsoft.com/en-us/library/ms256471.aspx
You can get all children elements using XElement.Elements().
Here's some code using recursion to get all elements of each level:
void GetElements(XElement element){
var elements = element.Elements();
foreach(Element e in elements){
//some stuff here
if(e.Elements() != null)
GetElements(e);
}
}
I have a function that returns the value from a specific tag in an XML document:
XElement elem = XElement.Parse(xml_string);
string ret = elem.Element(key).Value.ToString();
return ret;
I'm trying to figure out how to create another method that returns the full string contents contained within a tag, including child tags and child values.
i.e. if I have:
<foo>
Hello
<child1>val1</child1>
<child2>val2</child2>
</foo>
The method above properly returns 'Hello', but what I want is another method that returns:
Hello<child1>val1</child1><child2>val2</child2>
The easiest option is to spin through the collection returned by XElement.Nodes() and concatenate the XNode.ToString() values for all of those nodes. If you don't want it formatted (and it sounds like you don't), call XNode.ToString(SaveOptions.DisableFormatting)