I have an XmlNodeList of products whose values are put into a table. Now I want to add a new XmlNode to the list when a certain product is found so that in the same loop the new products is treated the same as the items that are originally in the file. This way the structire of the function does not need to change, just add an extra node that is processed next.
But an XmlNode is an abstract class and I cant figure out how to create the new node programatically. Is this possible?
XmlNodeList list = productsXml.SelectNodes("/portfolio/products/product");
for (int i = 0; i < list.Count; i++)
{
XmlNode node = list[i];
if (node.Attributes["name"].InnertText.StartsWith("PB_"))
{
XmlNode newNode = ????
list.InsertAfter(???, node);
}
insertIntoTable(node);
}
XmlDocument is the factory for its nodes so you have to do this:
XmlNode newNode = document.CreateNode(XmlNodeType.Element, "product", "");
Or its shortcut:
XmlNode newNode = document.CreateElement("product");
Then to add newly created node to its parent:
node.ParentNode.AppendChild(newNode);
If added node must be processed then you have to do it explicitly: node list is a snapshot of nodes that matched search condition then it won't be dynamically updated. Simply call insertIntoTable() for added node:
insertIntoTable(node.ParentNode.AppendChild(newNode));
If your code is much different you may need little bit of refactoring to make this process a two step batch (first search for nodes to add and then process them all). Of course you may even follow a completely different approach (for example copying nodes from XmlNodeList to a List and then adding them to both lists).
Assuming this is enough (and you do not need refactoring) let's put everything together:
foreach (var node in productsXml.SelectNodes("/portfolio/products/product"))
{
if (node.Attributes["name"].InnertText.StartsWith("PB_"))
{
XmlNode newNode = document.CreateElement("product");
insertIntoTable(node.ParentNode.AppendChild(newNode));
}
// Move this before previous IF in case it must be processed
// before added node
insertIntoTable(node);
}
Refactoring
Refactoring time (and if you have a 200 lines function you really need it, much more than what I present here). First approach even if not very efficient:
var list = productsXml
.SelectNodes("/portfolio/products/product")
.Cast<XmlNode>();
.Where(x.Attributes["name"].InnertText.StartsWith("PB_"));
foreach (var node in list)
node.ParentNode.AppendChild(document.CreateElement("product"));
foreach (var node in productsXml.SelectNodes("/portfolio/products/product"))
insertIntoTable(node); // Or your real code
If you do not like a two passes approach you may use ToList() like this:
var list = productsXml
.SelectNodes("/portfolio/products/product")
.Cast<XmlNode>()
.ToList();
for (int i=0; i < list.Count; ++i)
{
var node = list[i];
if (node.Attributes["name"].InnertText.StartsWith("PB_"))
list.Add(node.ParentNode.AppendChild(document.CreateElement("product"))));
insertIntoTable(node);
}
Please note that in second example the use of for instead of foreach is mandatory because you change the collection within the loop. Note that you may even keep your original XmlNodeList object in place...
You can't create an XmlNode directly, but only the subtypes (e.g. elements) by using one of the Create* methods of the parent XmlDocument. E.g. if you want to create a new element:
XmlElement el = doc.CreateElement("elementName");
node.ParentNode.InsertAfter(el, node);
Please note that this will not add the element to the XmlNodeList list so the node won't be processed. All necessary processing of the node should therefore be done right when adding the node.
Related
I was wondering how could I prevent the repetition of a root node or child nodes within that root node? As well as any child nodes of a child node etc. Keep in mind these nodes are based off inputted directories (I don't want to use Directory.GetDirectories or anything).
For example, if I inputted these three things:
cat\dog\monkey
cat\dog\tree
cat\dog\tree\monkey
Then the TreeView would look like this:
cat
dog
monkey
tree
monkey
I know this task may seem really easy, and for all I know it could be, but for some reason, I find it quite hard to do this. I also need to easily be able to associate the last node of each inputted directory with an object. So for example, "tree" would have data associated with it, etc. The process should be usable as many times as I like, in case I later decide to input more directories into the TreeView.
Thanks!
Edit: Figured it out.
split your input
get count of every args
check if there is already existing node on certain dimension
add or skip
example code looks like this. (This code may not be optimized code)
string[] input;
int count = input.Count;
getinput(input);
TreeNode CurrentNode = new TreeNode("Root");
this.treeview1.Add(CurrentNode);
foreach(string[] inputVal in input) {
foreach(string[] sp in inputVal.Split('\\')) {
CurrentNode = this.treeview.FindNode("Root");
for(int i = 0; i<sp.Count; i++) {
bool findSign = false;
foreach(TreeNode TN in CurrentNode.ChildNodes) {
//find if current node contains node named with sp[i]
if(TN.Text == sp[i]) {
findSign = true;
CurrentNode = TN;//set Current node as found node
break;
}
}
if(findSign == false) {
//if node name wasn't found, add a new node on current node
TreeNode newNode = new TreeNode(sp[i]);
CurrentNode.Add(newNode);
CurrentNode = newNode;//add node and set as current
}
}
}
}
I have a XML Example:
<Fruits>
<Red_fruits>
<Red_fruits></Red_fruits>
</Red_fruits>
<Yellow_fruits>
<banana></banana>
</Yellow_fruits>
<Red_fruits>
<Red_fruits></Red_fruits>
</Red_fruits>
</Fruits>
I have 4 Red_fruits tags, 2 of them shares the same ParentNode (Fruits), I want to get those which have the same ParentNode.
But I just want those which have the same name (Red_fruits), which means Yellow_fruits tag isn't included.
This is the way I am doing right now using C# language:
XmlDocument doc = new XmlDocument();
string selectedTag = cmbX.text;
if (File.Exists(txtFile.text))
{
try
{
//Load
doc.Load(cmbFile.text);
//Select Nodes
XmlNodeList selectedNodeList = doc.SelectNodes(".//" + selectedTag);
}
Catch
{
MessageBox.show("Some error message here");
}
}
This is returning me all red_fruits, not just the ones that belongs to Fruits.
I can't make XmlNodeList = doc.SelectNodes("/Fruits/Red_fruits") because I want to use this code to read random XML files, so I don't know the exact name that specific node will have, I just need to put all nodes with the same name and same level into a XmlNodeList using C# Language.
Is there a way of achieve this without using LINQ? How to do that?
An understanding on the usage of Single Slash / and Double slash // can help here.
Let's see how / and // work in relation to the root node. When / is used at the beginning of a path:
/a
it will define an absolute path to node a relative to the root. As such, in this case, it will only find a nodes at the root of the XML tree.
When // is used at the beginning of a path:
//a
it will define a path to node a anywhere within the XML document. As such, in this case, it will find a nodes located at any depth within the XML tree.
These XPath expressions can also be used in the middle of an XPath value to define ancestor-descendant relationships. When / is used in the middle of a path:
/a/b
it will define a path to node b that is an immediate direct descendant (ie. a child) of node a.
When // used in the middle of a path:
/a//b
it will define a path to node b that is ANY descendant of node a.
Coming back to your question:
// using GetElementsByTagName() return all the Elements having name: Red_Fruits
XmlDocument doc = new XmlDocument();
XmlNodeList nodes= doc.GetElementsByTagName("Red_Fruits");
//Using SelectNodes() method
XmlNodelist nodes = doc.SelectNodes("//Fruits/Red_Fruits");
// This will select all elements that are children of the <Fruits> element.
In case <Fruits> is the root element use the Xpath: /Fruits/Red_Fruits. [ a single slash /]
If you're simply trying to find the "next" or "previous" iteration of a single node, you can do the following and then compare it to the name
XmlNode current = doc.SelectSingleNode("Fruits").SelectSingleNode("Red_fruits");
XmlNode previous = current.NextSibling;
XmlNode next = current.NextSibling;
and you can iterate until you find the proper sibling
while(next.Name != current.Name)
{
next = next.NextSibling;
}
or you can even get your list by invoking the 'Parent' property
XmlNodeList list = current.ParentNode.SelectNodes(current.Name);
Worst case scenario, you can cycle through the XMLNode items in selectedNodeList and check the ParentNode properties. If necessary you could go recursive on the ParentNode check and count the number of times it takes to get to the root node. This would give you the depth of a node. Or you could compare the ParentNode at each level to see if it is the parent you are interested in, if that parent is not the root.
public void Test(){
XmlDocument doc = new XmlDocument();
string selectedTag = cmbX.text;
if (File.Exists(txtFile.text))
{
try
{
//Load
doc.Load(cmbFile.text);
//Select Nodes
XmlNodeList selectedNodeList = doc.SelectNodes(".//" + selectedTag);
List<XmlNode> result = new List<XmlNode>();
foreach(XmlNode node in selectedNodeList){
if(depth(node) == 2){
result.Add(node);
}
}
// result now has all the selected tags of depth 2
}
Catch
{
MessageBox.show("Some error message here");
}
}
}
private int depth(XmlNode node) {
int depth = 0;
XmlNode parent = node.ParentNode;
while(parent != null){
parent = node.ParentNode;
depth++;
}
return depth;
}
I have xml as follows:
<Reports>
<report>
<name>By Book</name>
<report_type>book</report_type>
<Object>Count Change</Object>
<Slicers detail="detail">
<Namespace>EOD</Namespace>
<BookNode>HighLevel</BookNode>
<DateFrom>T-2</DateFrom>
<DateTo>T-1</DateTo>
<System>NewSystem</System>
</Slicers>
</report>
</Reports>
I simply want to loop through the value of each element of the Xdocument (pref would be any element under Slicers) but to start with just all elements.
When I run the following:
var slicers = from c in config.Elements("Reports")
select c.Value ;
foreach (var xe in slicers)
{
Console.WriteLine(xe);
}
The output is a single line concatenating all the values together.
"By BookbookCount ChangeEODHighLevelT-2T-1NewSystem"
I want to loop through them one at a time, 'By Book' first, run some code then book etc etc.
I am sure this is simple, but cant get round it. I have tried foreach(Xelement in query) but same resulst
i would do it something like this;
XmlDocument doc = new XmlDocument();
doc.LoadXml(xml);
//load in your xml here
XmlNodeList xnList = doc.SelectNodes("nodeYou'reLookingFor");
//for getting just the splicers you could do "Reports/report/Slicers"
foreach (XmlNode node in xnList)
string namespace = node["Namespace"].InnerText;
//go through all your nodes here
you're creating a xmldoc, loading your xml into it, creating a list which holds each node in the list (at a specified Xpath), and then looping through each. in the loop you can do whatever you want by referencing
node["nodenamehere"].InnerText
string XML1 = "<Root><InsertHere></InsertHere></Root>";
string XML2 = "<Root><child1><childnodes>data</childnodes><childnodes>data1</childnodes></child1><child2><childnodes>data</childnodes><childnodes>data1</childnodes></child2></Root>";
Among below mentioned two code samples.. usage of childNodes doesn't copy all the child nodes from XML2. only <child1> is being copied.
string strXpath = "/Root/InsertHere";
XmlDocument xdxmlChildDoc = new XmlDocument();
XmlDocument ParentDoc = new XmlDocument();
ParentDoc.LoadXml(XML1);
xdxmlChildDoc.LoadXml(XML2);
XmlNode xnNewNode = ParentDoc.ImportNode(xdxmlChildDoc.DocumentElement.SelectSingleNode("/Root"), true);
if (xnNewNode != null)
{
XmlNodeList xnChildNodes = xnNewNode.SelectNodes("/*");
if (xnChildNodes != null)
{
foreach (XmlNode xnNode in xnChildNodes)
{
if (xnNode != null)
{
ParentDoc.DocumentElement.SelectSingleNode(strXpath).AppendChild(xnNode);
}
}
}
}
code2:
if (xnNewNode != null)
{
XmlNodeList xnChildNodes = xnNewNode.ChildNodes;
if (xnChildNodes != null)
{
foreach (XmlNode xnNode in xnChildNodes)
{
if (xnNode != null)
{
ParentDoc.DocumentElement.SelectSingleNode(strXpath).AppendChild(xnNode);
}
}
}
}
ParentDoc.OuterXML after executing first sample of code:
<Root>
<InsertHere>
<child1>
<childnodes>data</childnodes>
<childnodes>data1</childnodes>
</child1>
<child2>
<childnodes>data</childnodes>
<childnodes>data1</childnodes>
</child2>
</InsertHere>
</Root>
ParentDoc.OuterXML after executing second sample of Code
<Root>
<InsertHere>
<child1>
<childnodes>data</childnodes>
<childnodes>data1</childnodes>
</child1>
</InsertHere>
</Root>
I have done some debugging of the code, and it shows that xnNewNode.ChildNodes initially also returns 2 child nodes. After one iteration in the loop, the first child is however removed from ChildNodes, and therefore the loop ends prematurely.
If you want to use the ChildNodes property, one workaround is to "transfer" the child node references to an array or list, like this:
var xnChildNodes = xnNewNode.ChildNodes.Cast<XmlNode>().ToArray();
UPDATE
As Tomer W pointed out in his answer, when using XmlNode.AppendChild the inserted node is also removed from its original location. As stated in the MSDN documentation:
If the newChild is already in the tree, it is removed from
its original position and added to its target position.
With SelectNodes you have already created a new node collection, but with ChildNodes you are accessing the original collection.
this is a clearing of what Anders G posted, with more through explanation.
I am surprised the foreach does not fail (Throw Exception) in this situation, but hell.
In code1.
1. Create a NEW COLLECTION of nodes
2. Select nodes to it
3. append to other node => removing from original collection, but not the newly created one.
4 you are removing the node you are adding from the newly collection.
in Code2
1. Reference the ORIGINAL node collection
{child1, child2}
2. append 1st Node away to another collection => removing it from the original collection
{child2}
3. now when the foreach at index 1, it see that it passed the end of the collection. and exit.
this happens a lot when changing a collection that is subject to iteration.
but most the time, the IEnumerator is throwing an Exception when such happens.
hope i made it all clear
I had the same problem and observed, that whitespace nodes seem to have a value attached to the node, which is not the case with other nodes (at least in my application).This method removes the whitespace nodes from the node.ChildNodes list:
private List<XmlNode> findChildnodes(XmlNode node)
{
List<XmlNode> result = new List<XmlNode>();
foreach (XmlNode childnode in node.ChildNodes)
{
if(childnode.Value == null)
{
result.Add(childnode);
}
}
return result;
}
In answer to your question, Node.childNodes is All of the child nodes, whereas Node.SelectNodes(/*) is all of the child nodes that match /*. Only XML elements will match /*, so any attributes, CDATA nodes, text nodes, etc will be excluded.
Nevertheless, the problem occurs because you are changing the collection of nodes while while iterating over them. You cannot do that. The select nodes method returns a list of references to nodes. This is why is works.
We are interested in finding maximum number of attributes a node has in a XML document. My code is below using C#:
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(#"C:\ABC.xml");
XmlNode root = xmlDoc.DocumentElement;
int nodeAttrCount = 0;
foreach (XmlNode node in root)
if (nodeAttrCount < node.Attributes.Count)
nodeAttrCount = node.Attributes.Count;
We are interested is: do we have any thing better than this. Like any method or property which give us the same result or anyother option.
You can also use LINQ to XML:
XElement el = XElement.Load("MyXML.xml");
int maxAttr = el.DescendantNodesAndSelf().OfType<XElement>().Max(x => x.Attributes().Count());
The above code traverses all the xml nodes (it works with nested nodes too) and get the maximum number of attributes.
For .net 2.0:
XmlDocument doc = new XmlDocument();
doc.Load("MyXML.xml");
int max = 0;
foreach (XmlNode xmlNode in doc.SelectNodes("//*"))
if (max < node.Attributes.Count)
max = node.Attributes.Count;
This is basically the same as your solution;
the main difference is that it considers all nodes at every nesting level (using XPath navigation).
This is three lines of code for a fairly niche requirement. I wouldn't expect this to already exist in the .NET framework.
Your foreach loop looks fine. Are you sure you want to only look at the root elements, and not recurse inside the document?