Develop Reference

Reading xml file on some condition

I want to use a xml file which is as below
<?xml version="1.0" encoding="utf-8" ?>
<pages>
<page name="Default.aspx">
<method name="Login_click">
<message code="0" description="this is a test description">
<client code="0000000000" description="this is a description for clent 0000000000" />
</message>
</method>
</page>
</pages>
Now I want to create a function like below
public static string GetAppMessage(string pageName, string methodName, string clientCode, string code)
{
var xmlFile = HttpContext.Current.Server.MapPath("~/App_Data/Theme.xml");
var doc = new XmlDocument();
doc.Load(xmlFile);
if (string.IsNullOrEmpty(clientCode))
{
//go to node who page name to pageName
//and read the vlue
}
else
{
//read for a particular client code
}
}
How can I do this.
Edit 1
Do I need to loop through each node or can I reach to a particular node directly and find the decedent nodes.
like below
foreach (XmlNode chldNode in doc.ChildNodes)
{
....

Instead of XmlDocument you can use XDocument and LINQ to xml:
var xmlFile = HttpContext.Current.Server.MapPath("~/App_Data/Theme.xml");
XDocument xmlDoc = XDocument.Load(xmlFile);
var xmlPage = (from page in xmlDoc.Descendants()
where page.Name.LocalName == "page"
&& page.Attribute("name").Value == pageName
select page).FirstOrDefault();
if (xmlPage != null)
{
//do what you need
}

When you use XmlDocument and you know how the XML-file will look like (I mean you know the names of the nodes where the information is inside) then you could do something like this:
XmlDocument doc = new XmlDocument();
doc.Load(path);
XmlElement root = doc["NameOfRootNode"];
if (root != null)
{
//For nodes you just need to bypass to get to another subnode:
XmlNode node = root.SelectSingleNode("nameOfAnotherNode");
//For nodes you actually want to do something with, like read text, attribute etc.
if (node != null && node.SelectSingleNode("nameOfOneMoreNode") != null)
{
var xmlElement = node["nameOfOneMoreNode"];
if (xmlElement != null)
{
//Read from the xmlElement you selected and do something with it...
}
}
//...
}
With SelectSingleNode or SelectNodes you can maneuver to a specific known node and can read the InnerText or an Attribute.

You can use XPath to get <page> element by it's name attribute, for example :
string xpath = "//page[#name='{0}']";
XmlNode page = doc.SelectSingleNode(string.Format(xpath, pageName));
//and read the vlue
Basically, above XPath look for <page> element having name attribute equals pageName parameter.

3 Attempts to delete XML node using C#

I've tried deleting a node from my XML file 3 different ways; and each way I've come up empty. I am querying a SQL database and grabbing a filename, I want to delete the entire node were the file name in the XML document is = to the SQL database result.
I'm not sure what's wrong in my code:
Background Information
fn44 is the Filename grabbed from a SQL database (all my info is in a
SQL table, I need an XML file for use with JavaScript)
XML:
<?xml version="1.0" encoding="utf-8"?>
<xml>
<bannerMain>
<department>main</department>
<filename>resdrop.png</filename>
<title>This is a Title</title>
<text><![CDATA[caption text]]></text>
</bannerMain>
</xml>
Attempt 1 (I know that I'm not getting to the child correctly, can't seem to figure out how to fix it):
XDocument doc = XDocument.Load(Server.MapPath("~/uploads/banners.xml"));
var q = from node in doc.Descendants("bannerMain")
let fina = node.Descendants("filename")/*PROBLEM LINE*/
where fina != null && fina == myReader[0]/*Gets filename from SQL database*/
select node;
q.ToList().ForEach(x => x.Remove());
doc.Save(Server.MapPath("~/uploads/banners.xml"));
Attempt 2 (should work in my mind but doesn't)
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(Server.MapPath("~/uploads/banners.xml"));
XmlNode nodeToDelete = xmlDoc.SelectSingleNode("/xml/bannerMain[#filename="
+ fn44 + "]");
if (nodeToDelete != null)
{
nodeToDelete.ParentNode.RemoveChild(nodeToDelete);
}
xmlDoc.Save(Server.MapPath("~/uploads/banners.xml"));
Attempt 3 (similar to attempt 2)
string nodeToDelete = fn44;
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(Server.MapPath("~/uploads/banners.xml"));
XmlNode node = xmlDoc.SelectSingleNode(string.Format("//*[filename=\"{0}\"]"
, nodeToDelete));
if (node != null)
xmlDoc.SelectSingleNode("xml/bannersMain").RemoveChild(node);
xmlDoc.Save(Server.MapPath("~/uploads/banners.xml"));
I want to delete the whole node where the filename is = to the filename that is grabbed from the SQL database. Any help/resources is much appreciated.
SOLVED:
There's a few different options in the below answers that work out well.
Solution 1:
var xDoc = XDocument.Load(Server.MapPath("~/uploads/banners.xml"));
string fileName = fn44; //Use whatever value you found in SQL DB...
xDoc.Descendants("filename").Where(c => c.Value == fileName).Select(x => x.Parent).Remove();
xDoc.Save(Server.MapPath("~/uploads/banners.xml"));
Solution 2:
XDocument doc = XDocument.Load(Server.MapPath("~/uploads/banners.xml"));
var q = from node in doc.Descendants("bannerMain")
let fina = node.Element("filename")
where fina != null && fina.Value == fn44
select node;
q.Remove();
doc.Save(Server.MapPath("~/uploads/banners.xml"));

That seems to work for me:
string xmlfile = Server.MapPath("~/uploads/banners.xml");
var xDoc = XDocument.Load(xmlfile);
string fileName = "resdrop.png"; // Value from SQL DB
xDoc.Descendants("filename")
.Where(c => c.Value == fileName)
.Select(x => x.Parent)
.Remove();
xDoc.Save(xmlfile);

Your problem with attempt #1 is that you are trying to compare an IEnumerable<XElement> to your reader value, this should work (assuming each bannerMain only has a single filename element):
var q = from node in doc.Descendants("bannerMain")
let fina = node.Element("filename")//only single filename, so get just that XElement
where fina != null && fina.Value == reader[0]//assumes reader[0] is a string value
select node;
To remove them just do this:
q.Remove();
doc.Save(Server.MapPath("~/uploads/banners.xml"));
I ran this through LINQPad and after doing q.Remove();, here were the contents of doc: <xml />.

It's a little verbose but here is a non-linq snippet:
void DeleteNode(string fileName)
{
XmlDocument doc = new XmlDocument();
doc.Load(Server.MapPath("~/uploads/banners.xml"));
//Get all the bannerMain nodes.
XmlNodeList nodelist = doc.SelectNodes("/xml//bannerMain");
if (nodelist != null)
{
foreach (XmlNode node in nodelist)
{
//Look for then filename child. If it contains desired value
//delete the entire bannerMain node. Assumes order of child nodes
//may not be a constant.
foreach (XmlNode child in node.ChildNodes)
{
if (child.Name == "filename" && child.InnerText == name)
{
node.ParentNode.RemoveChild(node);
}
}
}
doc.Save(Server.MapPath("~/uploads/banners.xml"));
}
}

For Attempt #2, remove the # sign for the filename. The # symbol represents an Attribute, but the filename is a child-node.
If your phrase doesn't work, I'd rephrase it a little from:
"/xml/bannerMain[filename=
to
"//bannerMain[filename=

XML element removal, just need to delete one element not the parent

Basically what I am trying to do is remove a VSLOC from the list. I don't want to remove everything that belongs to it.
<?xml version="1.0"?>
<GarageNumbers>
<G554>
<id>G554</id>
<VSLOC>V002</VSLOC>
<VSLOC>V003</VSLOC>
<VSLOC>V002</VSLOC>
</G554>
<G566>
<id>G566</id>
<VSLOC>V002</VSLOC>
<VSLOC>V003</VSLOC>
<VSLOC>V002</VSLOC>
</G566>
<G572>
<id>G572</id>
<VSLOC>V001</VSLOC>
<VSLOC>V002</VSLOC>
</G572>
</GarageNumbers>
So, what I have setup is a combobox that I select a G# from which brings up all the VSLOC associated with it in a Listbox. What I need to do is to select a item from the list box and remove the line from the listbox and from the xml document using a button. I have all this setup but when I hit the button it deletes G554 and all the elements with in.
So if I want to select V002 from the list in G554 I want it to just remove that VSLOC with that innertext.
XmlDocument xDoc = new XmlDocument();
xDoc.Load(Application.StartupPath + "/xmlData.xml");
foreach (XmlNode xNode in xDoc.SelectNodes("GarageNumbers/G554"))
if (xNode.SelectSingleNode("VSLOC").InnerText == "V002")
xNode.ParentNode.RemoveChild(xNode);
xDoc.Save(Application.StartupPath + "/xmlData.xml");

You should be able to drill down to the desired elements then remove them. For example, assuming your XML is in an XElement, this approach would work:
string targetCategory = "G554";
string vsloc = "V002";
xml.Element(targetCategory)
.Elements("VSLOC")
.Where(e => e.Value == vsloc)
.Remove();
If you're using an XDocument then add the Root property: xml.Root

var xDoc = XDocument.Load(fname);
var node = xDoc.Descendants("VSLOC")
.Where(e => (string)e.Parent.Element("id") == "G554")
.FirstOrDefault();
if (node != null) node.Remove();
xDoc.Save(fname);

Find element with specific attribute in xml?

I have the following xml:
<?xml version="1.0" encoding="utf-8" ?>
<layout>
<menu name="Employees" url="Employees.aspx" admin="0">
</menu>
<menu name="Projects" url="Projects.aspx" admin="1">
</menu>
<menu name="Cases" url="Cases.aspx" admin="1">
</menu>
<menu name="CaseView" url="CaseView.aspx" admin="1" hidden="1" parent="Projects">
</menu>
<menu name="Management" url="" admin="1">
<item name="Groups" url="Groups.aspx" admin="1" parent="Management"/>
<item name="Statuses" url="Statuses.aspx" admin="1"/>
</menu>
</layout>
Here I have CaseView and Groups that both have a 'parent' attribute.
Currently I iterate like this:
IEnumerable<XElement> menus =
doc.Element("layout").Elements();
foreach (var menu in menus)
{
string name = menu.Attribute("name").Value;
string active = "";
string url = menu.Attribute("url").Value;
if(activePage == url)
{
active = "class=\"active\"";
}
...
What I want is:
if(activePage == url || ActiveIsChildOf(name, activePage))
{
active = "class=\"active\"";
}
Essentially this method needs to find if an element with activePage as its url attribute exists. If it does, see if it has a parent attribute; if it does, check if the parent == name.
Is there some way to find an element by attribute or something?
ex:
XElement e = doc.GetByAttribute("url",activePage)
Thanks

Since you are using Linq to XML, you can use Descendants method - it returns all child elements, not just the direct children. After that, you can use LINQ to filter the results.
XDocument doc;
string activePage;
var activeMenu = doc.Descendants("menu")
.FirstOrDefault(o => o.Attribute("url").Value == activePage);
You might need to check if o.Attribute("url") does not return null (it does when the attribute does not exist) if you cannot guarantee that the source XML does not have such attribute for all menu elements.
You can also skip the argument to Descendants() to check all elements - in your sample data that would allow you to check both menu and item elements. For example:
var activeMenu = doc.Descendants()
.Where(o => o.Name == "menu" || o.Name == "item")
.FirstOrDefault(o => o.Attribute("url").Value == activePage);

If xpath is too cryptic, you can use LINQ:
IEnumerable<XElement> hits =
(from el in XMLDoc.root.Elements("item")
where (string)el.Attribute("url") == activePage
select el);
or like this:
XElement xml = XElement.Load(file);
XElement xele = xml.Elements("item").FirstOrDefault(e => ((string)e.Attribute("url")) == activePage);
if(null != xele )
{
// do something with it
}
And you probably want it case-insensitive:
XElement xml = XElement.Load(file);
XElement xele = xml.Elements("item").FirstOrDefault(e => StringComparer.OrdinalIgnoreCase.Equals((string)e.Attribute("url") , activePage));
if(null != xele )
{
// do something with it
}
If you want both menu and item, use this:
XElement xml = XElement.Load(file);
XElement xele = xml.Elements().FirstOrDefault(e => StringComparer.OrdinalIgnoreCase.Equals((string)e.Attribute("url") , activePage));
if(null != xele )
{
// do something with it
}

You can simply use xPath. It's a query language for XML.
You can formulate something like this :
var xDoc = new XmlDocument();
xDoc.Load("XmlFile.xml");
//Fetch your node here
XmlNode = xDoc.SelectSingleNode(/layout/menu[#url='activepage'][1]);
It returns a set of node and the index 1 is to get the first node of the given set.
You can always use xDoc.SelectNodes if you want all the matching nodes.
Since you are using LINQ you can simply include System.Xml.XPath and select nodes with XPathSelectElement or XPathSelectElements.

You can do that with XPath:
doc.SelectNodes("//*[#url='" + activePage + "']")
It will return all document items that have activePage as url attribute.

A case insensitive search example, converting xml to a dictionary:
Dim expandos = XDocument.Parse(Request("Xml")).Root.Elements.Select(
Function(e)
Dim expando As Object = New ExpandoObject,
dic = e.Attributes.ToDictionary(Function(a) a.Name.LocalName, Function(a) a.Value,
StringComparer.InvariantCultureIgnoreCase)
expando.PedidoId = dic("PedidoId")
expando.FichaTecnicaModeloId = dic("FichaTecnicaModeloId")
expando.Comodo = dic("Comodo")
expando.Cliente = dic("Cliente")
Return expando
End Function)

Modify Node Value C# with ID

Here is my XML :
<?xml version="1.0" encoding="utf-8" ?>
<Selection>
<ID>1</ID>
<Nom>Name 1</Nom>
<DateReference>0</DateReference>
<PrefixeMedia>Department</PrefixeMedia>
<FormatExport>1630</FormatExport>
<TraceAuto>Oui</TraceAuto>
<SubID></SubID>
</Selection>
<Selection>
<ID>2</ID>
<Nom>Name 1</Nom>
<DateReference>0</DateReference>
<PrefixeMedia>Department</PrefixeMedia>
<FormatExport>1630</FormatExport>
<TraceAuto>1</TraceAuto>
<SubID>1</SubID>
</Selection>
My problem is I would like to modify for example the node content of <Nom>Name 1</Nom> which is located in <Selection></Selection> which have <ID>1</ID> (Search by ID)
I'm using XElement and XDocument to do simple search but I need some help to solve this problem above. (Developpment on SilverLight
Best Regards.

Another way to do this is using XmlDocument:
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(#"\path\to\file.xml");
// Select the <nom> node under the <Selection> node which has <ID> of '1'
XmlNode name = xmlDoc.SelectSingleNode("/Selection[ID='1']/Nom");
// Modify the value of the node
name.InnerText = "New Name 1";
// Save the XML document
xmlDoc.Save(#"\path\to\file.xml");

If you don't know how to get at the correct <Nom> node to update, the trick is to first select a <Selection> node that contains the correct <ID> node, then you can get that <Nom> node.
Something like:
XElement tree = <your XML>;
XElement selection = tree.Descendants("Selection")
.Where(n => n.Descendants("ID").First().Value == "1") // search for <ID>1</ID>
.FirstOrDefault();
if (selection != null)
{
XElement nom = selection.Descendants("Nom").First();
nom.Value = "Name one";
}
Note 1: By using Descendants("ID").First() I expect every Selection node to contain an ID node.
Note 2: And every Selection node contains a Nom node
Note 3: Now you still have to store the whole XML, if that's what you need.