I have an xml document where i need to iterate over all nodes that are direct descendants of the parent.
For example i have the following xml document
<root>
<node1>val1</node1>
<node2>val2</node2>
<nodes>
<nestedNode>nestedvalue</nestedNode>
</nodes>
</root>
I have the following code which gets me all the elements:
XmlNodeList nodes = doc.SelectNodes("//*");
This returns node1, node2, and nestedNode. What i want is only node1 and node2 and to ignore any nested values.
Thanks in advance for any help.
To select elements that are children of the root element you would use the xpath:
/root/*
or in general:
/*/*
You should not traverse the all descendants here (//...) as that will go through all elements in the document. You would have to add additional filtering which would make the query unnecessarily complicated:
//*[parent::*[not(parent::*)]]
However, you want to filter out elements that do not have other child elements so you need to add the condition not(*):
/*/*[not(*)]
Related
I have the following XML and I want to be able to query the XML based on the depth of it. I am aware of the depth before hand.
UPDATED QUESTION:
I have the following XML and I want to be able to query the XML based on if the nodes are repetitive.
So, this is my XML
<Books>
<BookID>12345</BookID>
<BookName>BookName</BookName>
<Authors>
<Author>
<Name>AuthorNameOne</Name>
<City>New York</City>
</Author>
<Author>
<Name>AuthorNameTwo</Name>
<City>New York</City>
</Author>
</Authors>
</Books>
Via XDocument I want to be able to query this XML and get node names for the elements where there is repetitive data such as Authors. Or I want to be able to query it based on the Depth of the Node.
UPDATED QUESTION:
Via XDocument I want to be able to query this XML and get node names for the elements where there is repetitive data such as Authors.
Any help will be much appreciated.
Your XML still doesn't really make sense, but I'm putting together this answer hoping that it will at least point you in the right direction. I'm going to completely ignore the portion of your question that references node depth because I'm not really sure how it applies to the following question that you posted:
Via XDocument I want to be able to query this XML and get node names for the elements where there is repetitive data such as Authors.
Here's how to do just that simple type query assuming that your XDocument is named xml:
List<XElement> repeatedNodes = new List<XElement>();
for(XElement node in xml.Descendants())
{
if(node.Parent.Elements(node.Name).Count() > 1))
{
repeatedNodes.Add(node);
}
}
Here's the same code compressed into a lambda that will provide you with an IEnumerable<XElement> containing all of the elements that would go into the List in my first example:
var dupes = xml.Descandants().Where(n => n.Parent.Elements(n.Name).Count() > 1);
This algorithm will look at every node in the xml tree and then from the parent of the current node it will count how many nodes with that same name exist. If that number is greater than one it will add it to our list of repeated nodes. This does not care what depth the current node is and it will only count duplicate named nodes at the same depth. Additionally this algorithm will put dupes in the List structure, but you can add in your own logic to prevent it from doing that or use a different structure that doesn't allow duplicates.
I have xml document like this:
<level1>
<level2>
<level3>
<attribute1>...</attribute1>
<attribute2>false</attribute2>
<attribute3>...</attribute3>
</level3>
<level3>
<attribute1>...</attribute1>
<attribute2>true</attribute2>
<attribute3>...</attribute3>
</level3>
</level2>
<level2>
<level3>
<attribute1>...</attribute1>
<attribute2>false</attribute2>
...
...
...
I'm using c#, and I want to go thru all "level3", and for every "level3", i want to read attribute2, and if it says "true", i want to print the corresponding attribute3 (can be "level3" without these attributes).
I keep the xml in XmlDocument.
Then I keep all the "level3" nodes like this:
XmlNodeList xnList = document.SelectNodes(String.Format("/level1/level2/level3"));
(document is the XmlDocument).
But from now on, I don't know exactly how to continue. I tried going thru xnList with for..each, but nothing works fine for me..
How can I do it?
Thanks a lot
Well I'd use LINQ to XML:
var results = from level3 in doc.Descendants("level3")
where (bool) level3.Element("attribute2")
select level3.Element("attribute3").Value;
foreach (string result in results)
{
Console.WriteLine(result);
}
LINQ to XML makes all kinds of things much simpler than the XmlDocument API. Of course, the downside is that it requires .NET 3.5...
(By the way, naming elements attributeN is a bit confusing... one would expect attribute to refer to an actual XML attribute...)
You can use LINQ to XML and reading this is a good start.
You can use an XPath query. This will give you a XmlNodeList that contains all <attribute3> elements that match your requirement:
var list = document.SelectNodes("//level3[attribute2 = 'true']/attribute3");
foreach(XmlNode node in list)
{
Console.WriteLine(node.InnerText);
}
You can split the above xpath query in three parts:
"//level3" queries for all descendant elements named <level3>.
"[attribute2 = 'true']" filters the result from (1) and only keeps the elements where the child element <attribute2> contains the text true.
"/attribute3" takes the <attribute3> childnode of each element in the result of (2).
I would like to find all <Field /> nodes (that may be arbitrarily nested) inside a given XmlNode.
If do something like this:
foreach(XmlNode n in node.SelectNodes('//Field'))...
This returns all nodes in the entire document, not all nodes under node.
Is this how XPath is supposed to work? I looked at some documents and it seems like the //Node query should be scoped to whatever node it's invoked at.
Is there any other technique to select all nodes with a given name that are under a specific node?
If you use '//Field' it's absolut from the root of the document. To search relative to the current node, just use './/Field'.
Use ./Field.
.// Means descendants, which includes children of children (and so forth).
./ Means direct children.
If a XPath starts with a / it becomes relative to the root of the document; to make it relative to your own node start it with ./.
try to use SelecteSingleNode()
Remove // because otherwise it search among all the document irrelatively to the root node.
node.SelectNodes("Field")
You can use simple linq query like this:
var techLeads = (from value in element.Descendants ("Manager")
where value.Attribute ("Name").Value == "Mgr1"
select value).Descendants("TechLead");
Sample Xml:
<Employees>
<Manager Name="Mgr1">
<TechLead Name="TL1" />
<TechLead Name="TL2" />
</Manager>
</Employees>
Say i have the following xml file:
<a>
<b>
<c></c>
</b>
<b>
<c></c>
</b>
</a>
var nodes = doc.SelectNodes("/a/b");
will select the two b nodes.
I then loop these two nodes suchas:
foreach (XmlNode node in nodes) { }
However, when i call node.SelectNodes("/a/b/c"); It still returns both values and not just the descendants.
Is it possible to select nodes only descening from the current node?
In the foreach loop, you already know that node is a /a/b in the original document - so to get just its c children simply use a relative xpath:
node.SelectNodes("c")
You can use node.SelectSingleNode("C");
/a/b[1]/c
For intance gets the nodelist of all the children of the first b that have the tagname c.
To get the first c as a singleton nodelist use /a/b[1]/c[1]. /a/b/c[1] again returns a nodelist of multiple nodes.
SelectSingleNode is probably misleading, as far as I know, XPath always returns a nodelist, which can contain optionally one node (or even be empty).
//c[1] just selects the first c in the document.
Sample XML
<A>
<B>
<B1/>
<B2/>
<B3/>
<B4/>
<B5/>
</B>
<C>
<C1/>
<C2/>
<C3/>
<C4/>
<C5/>
</C>
</A>
Query:
C#
When I read the the child nodes of A it retuns nodes B & C with their child nodes.
Is there any possibility so that I can get only B & C without their respective child nodes
I need to populate the tree with this type of xml & the xml file is quite big. so I need to load the childs at the time of expanding any node
Requirement is
Suppose I try to expand A node the I want only B & C,
If I expand B then I want B1 to B5
Use a XmlReader. XmlDocument by design has to load the whole Xml document into memory.
if you use java, you can implement a SAX Handler building your DOM and ignoring the children.
It's a badly worded question so I'm not entirely sure what you are trying to do but if you just want all the child nodes of the root (A) then use an XmlDocument with XPath like this:
XmlDocument doc = new XmlDocument();
doc.Load(xmlFile);
XmlNodeList nodes = doc.SelectNodes("/A/*");
foreach(XmlNode node in nodes){
//DO STUFF
}
if i understand the question right, u need to get children of the node without getting their children. this can be done by xquery
(child::*)
so if u apply it in A node it will give B and C. if u apply it in B then it will give B1-B5.