I am trying to restrict duplicate entry to an XML file and below is the XML file.
<?xml version="1.0" standalone="yes"?>
<Info>
<Details>
<ID>Ryan</ID>
</Details>
<Details>
<ID>Danny</ID>
</Details>
</Info>
Now if I try to add Ryan or Danny again to the ID I should alert like user name already exists.
I'm using the below code and it doesn't work. strName is a string and has username value to be added. Can anyone provide suggestions?
XDocument xDoc = XDocument.Load(Server.MapPath("~/Info.xml"));
bool userExistsAlready = xDoc.Descendants("Details").Any(x => (string)x.Attribute("ID") == strName);
if (userExistsAlready)
{
//alert
}
Try this way:
bool userExistsAlready = xDoc.Descendants("Details")
.Elements("ID")
.Any(x => x.Value == "Ryan");
The problem with your code is that it tries to access attribute ID. But ID is in fact another XML element contained inside element <Details>.
You could set ID as an attribute of Details and then check if that entry exist using the XmlDocument method GetElementByID, or implement a for cycle that checks out the property InnerText of every element in the array resulting from the call to GetElementsByName method.
Related
I have the following XML sample.
<?xml version="1.0" encoding="utf-8"?>
<GlobalResponses>
<Filters>
<FilterId>11</FilterId>
<FilterId>5</FilterId>
<FilterId>10</FilterId>
</Filters>
<Responses>
<Response>
<Name>Bob</Name>
</Response>
<Response>
<Name>Jim</Name>
</Response>
<Response>
<Name>Steve</Name>
</Response>
</Responses>
</GlobalResponses>
Using XDocument, how can I get only the <Responses> parent and also child nodes, and convert them to a string variable. I looked at XDocument Elements and Descendants, but by calling oXDocument.Descendants("Responses").ToString(); didn't work.
Do I have to iterate over all of the XElements checking each one and then appending to a string variable ?
Function Descendants returns enumeration of XElement, so you need to select specific element.
If you want to get XML element with all the child nodes, you can use:
// assuming that you only have one tag Responses.
oXDocument.Descendants("Responses").First().ToString();
The result is
<Responses>
<Response>
<Name>Bob</Name>
</Response>
<Response>
<Name>Jim</Name>
</Response>
<Response>
<Name>Steve</Name>
</Response>
</Responses>
If you want to get child nodes and concatenate them to single string you can use
// Extract list of names
var names = doc.Descendants("Responses").Elements("Response").Select(x => x.Value);
// concatenate
var result = string.Join(", ", names);
The result is Bob, Jim, Steve
The Descendants() method takes input the element name and it will return you a collection of nodes and from those you then further need to get the elements you are interested in.
You can use linq with XDocument to extract the information. For example, the following code with extract the Name element value from each Response node and prints out :
var nodes = from response in Doc.Descendants("Response")
select response.Element("Name").Value;
foreach(var node in nodes)
Console.WriteLine(node);
Here above Doc.Descendants("Response") will fetch all the <Response> elements and then we are using response.Element("Name") to fetch the <Element> tag for each <Response> element and then using .Value property we get the value between the tag.
See this working DEMO fiddle.
I need to insert only unique values in my XML database based on the "userName" value. For example there can't be two players which has same name in the database. The implementation of my xml database which is named as "MyXML.xml" is like that :
<?xml version="1.0" encoding="utf-8"?>
<Players>
<player name="cag" score="5555" />
<player name="cihan" score="1222" />
<player name="can" score="333" />
</Players>
and my related code in order to detetect duplication is:
public bool insertUserDetails(string userName,float userScore){
XDocument doc = Document.Load(HttpContext.Current.Server.MapPath("MyXML.xml"));
var duplicate = doc.Element("Players").Elements("player").Where(x =>(string)x.Value == userName).SingleOrDefault();
if (duplicate != null){
return false;
}
else{
return true;
}
}
when I try to insert a duplicate value for example "can" and "333", var duplicate value turns out to be null. How can I fix this problem ?
"can" is defined as a attribute in your XML; It is not a value. Value is something which comes in between open and closing tags of xml.
For example, if you have a xml element like this
<SomeTag name="somename">Hello world</SomeTag>
Then, SomeTag is the element name, somename is the attribute value of attribute "name" and "Hello world" is the value of the xml element itself.
So, You need to find the attribute using Attribute method to access its value.
var duplicate = doc.Element("Players")
.Elements("player")
.Where(x=>x.Attribute("name").Value == userName)
.SingleOrDefault();
You're iterating over the Value of each player element, rather than the Attributes of those elements. Since there's no text inside the player element, the value is always an empty string, and thus never matched the name you're looking for. Instead, select the .GetAttribute("name") for each element
var duplicate = doc
.Element("Players")
.Elements("player")
.Select(ele => ele.GetAttribute("name"))
.Where(att =>(string)att.Value == userName)
.SingleOrDefault();
you're comparing the value of an XElement, "x", to userName.
you should compare the "name" attribute of x to it.
var duplicate = doc.Element("Players").Elements("player").Where(x => (string)x.Attribute("name").Value == userName).SingleOrDefault();
I have below a xml file with the below format:
<?xml version="1.0" encoding="utf-8" ?>
<Root>
<Countries>
<country>India</country>
<country>USA</country>
<country>UK</country>
</Countries>
</Root>
string newCountry="UAE"
I want to insert this "UAE" country to the above xml file, before that I want to check whether "UAE" is already exists in the xml. If not exists then only want to insert otherwise no operation. How can I do this?
Like this:
XDocument xml = XDocument.Load("path_to_file");
string newCountry = "UAE";
XElement countries = xml.Descendants("Countries").First();
XElement el = countries.Elements().FirstOrDefault(x => x.Value == newCountry);
if (el == null)
{
el = new XElement("country");
el.Value = newCountry;
countries.Add(el);
}
//Console.WriteLine(countries.ToString());
The easiest way would probably be to read the xml into C# objects, check for the existance of UAE, potentially add it, and write the objects back to XML.
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.
Friends,
My school project is having an xml data file:
<patients>
<patient>
<regNo>2012/Mar/003</regNo>
<name>Jhon</name>
<add>Somewhere</add>
<mobile>0000</mobile>
.
.
.
<stay>2</stay>
<costofroom>100</costofroom>
<total>200</total>
</patient>
</patients>
My Windowsform "EditPatients_Load" is able to fetch all info of patient Jhon, and now let's assume that the Admin needs to change some information in the form & resubmit.
Then how to write back all values to Jhon's account in the same xml
file????
I'm not able to makeup the logical code, even if I check the node if (patients.paptient.name = "nameComboBox.text").... how to make sure that I'm writing other values on proper place?
Rgrdz,
Try this:
//string xml =
//#"<patients><patient><regNo>2012/Mar/003</regNo><name>Jhon</name><add>Somewhere
//</add><mobile>0000</mobile><stay>2</stay><costofroom>100</costofroom><total>200</total>
//</patient></patients>";
XDocument xmlDoc = XDocument.Load(#"c:\abc.xml");
var items = (from item in xmlDoc.Descendants("patient")
where item.Element("name").Value == "Jhon"
select item);
if (items.Count() > 0)
{
var item = items.First();
item.SetElementValue("add", "New New Address");
xmlDoc.Save(#"c:\abc.xml", SaveOptions.None);
}
You can get single element using
var item = (from item in xmlDoc.Descendants("patient")
where item.Element("name").Value == "Jhon"
select item).FirstOrDefault();
then update it using SetElementValue() method.
//Updated Xml
<?xml version="1.0" encoding="utf-8"?>
<patients>
<patient>
<regNo>2012/Mar/003</regNo>
<name>Jhon</name>
<add>New Address</add>
<mobile>0000</mobile>
<stay>2</stay>
<costofroom>100</costofroom>
<total>200</total>
</patient>
</patients>
Reference:
Update XML with C# using Linq
I would take the xml serialization/deserialization route to solve this:
http://support.microsoft.com/kb/815813
How to Deserialize XML document
That way you can work with objects and not have to parse xml files manually.
If you're using .NET 3.5 onward you can use the XDocument class like the following. I'm assuming your content is in a .xml file.
XDocument xdoc = XDocument.Load(#"C:\Tmp\test.xml");
//this would ensure you get the right node and set its text content/value
xdoc.Element("patients")
.Element("patient").Element("add").Value = "some new address?";
xdoc.Save(#"C:\Tmp\test.xml");
The file test.xml would change to:
<patients>
<patient>
<regNo>2012/Mar/003</regNo>
<name>Jhon</name>
<add>some new address?</add>
<mobile>0000</mobile>
<stay>2</stay>
<costofroom>100</costofroom>
<total>200</total>
</patient>
</patients>