Develop Reference

How to get different values with same name from xml with linq

XML - Code:
<Store>
<Products>
<Product id="PROD01">
<Title>Product 1</Title>
<Description><![CDATA[Product <b>1</b> description]]></Description>
<Image>prod01.gif</Image>
<Specs>
<Spec>Good computer</Spec>
<Spec>Good display</Spec>
<Spec>Latest version</Spec>
</Specs>
<Availability>same day</Availability>
</Product>
<Product id="PROD02">
<Title>Product 2</Title>
<Description><![CDATA[Product <b>2</b> description]]></Description>
<Image>prod01.gif</Image>
<Specs>
<Spec>Good computer</Spec>
<Spec>Soon available</Spec>
</Specs>
<Availability>next day</Availability>
</Product>
</Products>
</Store>
C# - Code:
public List<DetailList> GetDetails()
{
DetailList d = new DetailList();
List<DetailList> DetailLists =
(from product in xdocList.Descendants("Product")
join detail in xdocDetail.Descendants("Product")
on (string)product.Attribute("id") equals (string)detail.Attribute("id")
into outerProducts
from outerProduct in outerProducts
select new DetailList
{
Detail1 = (string)product.Attribute("id"),
Detail2 = (string)product.Element("Title"),
Detail3 = (string)product.Element("Description"),
Detail4 = (string)product.Element("Image"),
Detail5 = (string)outerProduct.Elements("Specs")
Detail6 = (string)outerProduct.Element("Availability"),
Detail7 = (string)product.Element("Price"),
}).ToList();
return DetailLists;
}
Output: Good computerGood displayLatest version
But wanted output is:
Good computer
Good display
Latest version
For output I used asp:repeater. I tried to add tags like < b r/> and much more, but cant'find my mistake, how to get Spec to three different strings, not only one string. How to achive that?

I am not sure why you are joing the nodes with self, but as per your XML it is not required. You can simply project the elements like this:-
public static List<DetailList> GetDetails(XDocument xdocList)
{
DetailList d = new DetailList();
List<DetailList> DetailLists = (from product in xdocList.Descendants("Product")
select new DetailList
{
Detail1 = ((string)product.Attribute("id")),
Detail2 = ((string)product.Element("Title")),
Detail3 = ((string)product.Element("Description")),
Detail4 = ((string)product.Element("Image")),
Detail5 = product.Element("Specs")
.Elements("Spec")
.Select(x => (string)x).ToList(),
Detail6 = ((string)product.Element("Availability")),
Detail7 = ((string)product.Element("Price")),
}).ToList();
return DetailLists;
}
Since you need all the Specs separately, you should have a collection of string and not just string. So the datatype of property Detail5 should be:-
List<string> or string[]

Friend got solution from Rahul
Detail5 = String.Join("<br/>", outerProduct.Element("Specs").Elements("Spec").Select(x => (string)x).ToList()),
Thanks #Rahul Singh

Linq never finding element in XDocument

I have the following XDocument called XDoc:
<?xml version="1.0" encoding="utf-8"?>
<DatabaseList>
<Database DatabaseName="c2501_data">
<Plugin PluginName="FooPlugin" LastRun="1/21/2013 3:22:08 PM" />
<Plugin PluginName="SpecialPlugin" LastRun="2013-01-21T15:22:09.3791103-05:00" />
<Plugin PluginName="BarPlugin" LastRun="2013-01-21T15:23:13.0964814-05:00" />
</Database>
</DatabaseList>
I'm writing a program that searches to see when the last time a plugin was run on a database, if at all. I use the following two pieces of code to figure out if an entry exists for a plugin on a database:
var h = (from el in XDoc.Root.Elements("Database")
where el.Element("Plugin").Attribute("PluginName").Value=="FooPlugin"
&& el.Attribute("DatabaseName").Value=="c2501_data"
select el.Element("Plugin"));
var e = (from el in XDoc.Root.Elements("Database")
where el.Element("Plugin").Attribute("PluginName").Value=="BarPlugin"
&& el.Attribute("DatabaseName").Value == "c2501_data"
select el.Element("Plugin"));
if ((from el in XDoc.Root.Elements("Database")
where el.Element("Plugin").Attribute("PluginName").Value == "BarPlugin"
&& el.Attribute("DatabaseName").Value == "c2501_data"
select el.Element("Plugin")).Count() == 0)
{
XElement SpecialPlugin = new XElement("Plugin",
new XAttribute("PluginName", "BarPlugin"),
new XAttribute("LastRun", DateTime.Now));
var CurNode = from node in XDoc.Root.Elements("Database")
where (string)node.Attribute("DatabaseName").Value == "c2501_data"
select node;
foreach (var node in CurNode)
node.Add(SpecialPlugin);
XDoc.Save(RuntimesPath);
//XDoc.Root.Elements("Database").Attribute("DatabaseName").
}
The problem that I'm having is that even though there is clearly an entry for BarPlugin, the count will always return 0 and e will always be unable to create an enumberable. Can anyone explain to me why this might be? FooPlugin always works correctly and returns the Plugin information for h.
Thanks for any help.

You're selecting a Database element where it contains a child element called Plugin with a given name. Since you have only one Database element, you're getting the same outer element each time. You then take that database element and return the first Plugin child, which will always be Foo, in this case. You need to find the appropriate Database element and then query through each of the child elements so you can return them:
public static XElement GetPlugin(XDocument XDoc, string databaseName, string pluginName)
{
var h = from database in XDoc.Root.Elements("Database")
where database.Attribute("DatabaseName").Value == databaseName
from plugin in database.Elements("Plugin")
where plugin.Attribute("PluginName").Value == pluginName
select plugin;
return h.FirstOrDefault();
}
Or, if you prefer, in method syntax:
var q = XDoc.Root.Elements("Database")
.Where(db => db.Attribute("DatabaseName").Value == databaseName)
.SelectMany(db => db.Elements("Plugin"))
.Where(plugin => plugin.Attribute("PluginName").Value == pluginName);
return q.FirstOrDefault();

Try this:
var db = XDoc.Root.Elements("Database");
var z = (from el in db.Elements("Plugin")
where el.Attribute("PluginName").Value == "BarPlugin"
&& el.Parent.Attribute("DatabaseName").Value == "c2501_data"
select el).FirstOrDefault();
if(z != null)
.....
I'm using Elements() method, to get all child elements and Parent property to look for the parent element "DatabaseName".
Problem in your code is that your el.Element() is searching only for the first element, thus it can find only "FooPlugin", which is on the first position in the xml.
From MSDN doc Element():
Gets the first (in document order) child element with the specified XName.

I'm confused by Linq XML query

Here is my XML sample. I want to select SystemSetting's value if ID = 123. But I can't figure out how. How can I select SystemSetting value if id's value equal to 123 ?
<?xml version="1.0" encoding="utf-8" ?>
<Private>
<System>
<ID>123</ID>
<NAME>Test</NAME>
<SystemSetting>128</SystemSetting>
<SystemSettingCS>127</SystemSettingCS>
</System>
<System>
<ID>124</ID>
<NAME>Test2</NAME>
<SystemSetting>128</SystemSetting>
<SystemSettingCS>127</SystemSettingCS>
</System>
<System>
<ID>0</ID>
<NAME>Test</NAME>
<SystemSetting>5</SystemSetting>
<SystemSettingCS>250</SystemSettingCS>
</System>
</Private>
Here's what I tried:
var doc = XDocument.Load(Application.StartupPath+ #"\Settings.xml");
var q = from Ana in doc.Descendants("Private")
from sistem in Ana.Elements("System")
where (int)sistem.Element("ID") == 123
from assetText in Sistem.Elements("System")
select assetText.Element("SystemSetting");
MessageBox.Show(q.ToString());
thnx for help.

I think you're making this more complicated than you need to. I think you just need:
var query = doc.Descendants("Private") // Or just doc.Root
.Elements("System")
.Where(x => (int) x.Element("ID") == 123)
.Select(x => x.Element("SystemSetting"))
.FirstOrDefault();
That will select the first matching element, admittedly. The type of query is then XElement; if you take off the FirstOrDefault() part, it will return an IEnumerable<XElement>, for all matching elements.
If you want just the value instead of the element, you can change the Select to:
.Select(x => (string) x.Element("SystemSetting"))
or
.Select(x => x.Element("SystemSetting").Value)
(The first will return null if there's no SystemSetting element; the second will throw an exception.)

Xpath (System.Xml.XPath) can really help here
var system = doc.XPathSelectElement("//System[ID[text()='123']]");
var val = system.Element("SystemSetting").Value;
or with a single line
var s = (string)doc.XPathSelectElement("//System[ID[text()='123']]/SystemSetting");

Your almost there
var xmlFile = XElement.Load(#"c:\\test.xml");
var query =
from e in xmlFile.Elements()
where e.Element("ID").Value == "123"
select e.Element("SystemSetting").Value;

var q = from s in doc.Descendants("System")
where (int)s.Element("ID") == 123
select (int)s.Element("SystemSetting");
And show result (q will have IEnumerable<int> type):
if (q.Any())
MessageBox.Show("SystemSettings = " + q.First());
else
MessageBox.Show("System not found");

Was a Linq question, but there is an alternate XPath approach, but the class defined below could work in either scenario.
Define a class to read from the parent System element:
public class XSystem
{
public XSystem(XElement xSystem) { self = xSystem; }
XElement self;
public int Id { get { return (int)self.Element("ID"); } }
public string Name { get { return self.Element("NAME").Value; } }
public int SystemSetting { get { return (int)self.Element("SystemSetting"); } }
public int SystemSettingCS { get { return (int)self.Element("SystemSettingCS"); } }
}
Then find your System element that has a child ID element of 123.
int id = 123;
string xpath = string.Format("//System[ID={0}", id);
XElement x = doc.XPathSelectElement(xpath);
Then plug it into the class:
XSystem system = new XSystem(x);
Then read the value you want:
int systemSetting = system.SystemSetting;
XPath is defined with using System.Xml.XPath;

C# Linq XML, check for specific value and parse to array

I have the following XML:
<?xml version="1.0" ?>
<NewDataSet>
<Data>
<ElementDefinition>
<ID>1</ID>
<QUANTITY>0</QUANTITY>
</ElementDefinition>
<ElementDefinition>
<ID>2</ID>
<QUANTITY>1</QUANTITY>
</ElementDefinition>
</Data>
</NewDataSet>
I need to create an array which contains all ElementDefinitions which contain a QUANTITY element with a value other then 0.
I tried:
var f = XDocument.Load(path);
var xe = f.Root.Elements("QUANTITY").Where(x => x.Value != "0").ToArray();
But that doesn't seem to work. With the above XML the array should contain 1 item, but it stays 0.
After that I need to create a string for each ElementDefinition in the array, the string must contain the value of the corresponding ID element.
For that I tried:
foreach (string x in xe)
{
string ID = //not sure what to do here
}

You want something like this:
var ids = f.Root.Descendants("ElementDefinition")
.Where(x => x.Element("QUANTITY").Value != "0")
.Select(x => x.Element("ID").Value);
As you want the ID, it is not very helpful to select all QUANTITY nodes. Instead, select exactly what you specified in your question:
All ElementDefinitions (Descendants("ElementDefinition")), that have a QUANTITY with a Value other than 0 (Where(x => x.Element("QUANTITY").Value != "0"). From the resulting nodes, select the ID (Select(x => x.Element("ID").Value)).

Yo can replace with
var xe = f.Root.Elements("Data/ElementDefinition/QUANTITY").Where(x => x.Value != "0").ToArray();

Select statement for xdoc query

I am trying to add a sub category to Messages in my xml statement Is there a way I can do this GroupMessages -> Message -> GroupMessage :
var groups = xDoc.Descendants("Group")
.Select(n => new
{
GroupName = n.Element("GroupName").Value,
GroupHeader = n.Element("GroupHeader").Value,
TimeCreated = DateTime.Parse(n.Element("TimeAdded").Value),
Tags = n.Element("Tags").Value,
Messages = n.Element("GroupMessages").Value
//line above
})
.ToList();
dataGrid2.ItemsSource = groups;
In my method GroupMessages contains both MessageID and GroupMessage and it is listing both in my datagrid within the one container. So I tried this but it lists nothing:
Messages = n.Descendants("GroupMessages").Select(nd => nd.Element("GroupMessage").Value)
My XML looks like this:
<Group>
<TimeAdded>2012-04-27T10:23:50.7153613+01:00</TimeAdded>
<GroupName>Group</GroupName>
<GroupHeader>Header</GroupHeader>
<GroupMessages>
<Message>
<MessageID>1</MessageID>
<GroupMessage>Message</GroupMessage>
<MessageGroup/>
</Message>
</GroupMessages>
</Group>
I have also tried:
Messages = n.Descendants("GroupMessages").Select(nd => nd.Descendants("Message").Select(nde => nde.Element("GroupMessage").Value))
To no avail?
Update:
private void ListGroups_Click(object sender, RoutedEventArgs e)
{
string uriGroup = "http://localhost:8000/Service/Group";
XDocument xDoc = XDocument.Load(uriGroup);
var groups = xDoc.Descendants("Group")
.Select(n => new
{
GroupName = n.Element("GroupName").Value,
GroupHeader = n.Element("GroupHeader").Value,
TimeCreated = n.Element("TimeAdded").Value,
Tags = n.Element("Tags").Value,
Messages = n.Element("GroupMessages").Descendants("Message").Select(nd => new
{
//Id = nd.Element("MessageID").Value,
Message = nd.Element("GroupMessage").Value
}).FirstOrDefault()
})
.ToList();
dataGrid2.ItemsSource = groups;
}
Unfortunatley this method shows "Collection" inside the cell in the datagrid. If I try ToArray it will show an array message inside the cell. Is there a way to actually display the GroupMessage? Not sure how you set the child elements of a datagrid?

At the most basic level, you can do this to get a single message (the first one):
var groups = from grp in xDoc.Descendants("Group")
select new {
GroupName = grp.Element("GroupName").Value,
GroupHeader = grp.Element("GroupHeader").Value,
TimeCreated = DateTime.Parse(grp.Element("TimeAdded").Value),
Message = grp.Element("GroupMessages").Element("Message").Element("GroupMessage").Value
};
However, I assume that you want Messages to be a list of messages with both ID and Message. In that case, consider this:
var groups = from grp in xDoc.Descendants("Group")
select new {
GroupName = grp.Element("GroupName").Value,
GroupHeader = grp.Element("GroupHeader").Value,
TimeCreated = DateTime.Parse(grp.Element("TimeAdded").Value),
Messages = grp.Element("GroupMessages")
.Descendants("Message")
.Select(msg => new {
Id = msg.Element("MessageID").Value,
Message = msg.Element("GroupMessage").Value
}).ToList()
};
However, I strongly stress that all this usage of anonymous classes is just going to cause confusion. If you have a class for Group and Message then use those.
Note that the problem you're having is you're ignoring the XML structure and selecting random elements. To get the value out of a single element, you're going to need to select exactly that element, and ask for .Value. Selecting it's parent, or it's parent's parent (as you did) is not enough.

Try this:
var groups = xDoc.Elements("Group")
.Select(n => new
{
GroupName = n.Get("GroupName", string.Empty),
GroupHeader = n.Get("GroupHeader", string.Empty),
TimeCreated = n.Get("TimeAdded", DateTime.MinValue),
Tags = n.Get("Tags", string.Empty),
Messages = n.GetEnumerable("GroupMessages/Message", m => new
{
Id = m.Get("MessageID", 0),
Message = m.Get("GroupMessage", string.Empty),
Group = m.Get("MessageGroup", string.Empty)
}).ToArray()
})
.ToList();
I used the extension methods from here: http://searisen.com/xmllib/extensions.wiki
Get will handle null cases like your Tags node that doesn't exist in your xml, as well as the empty tag MessageGroup. You should use Elements() if the node you want is the child of the node you are referencing and not any descendant by that name.
I copied your xml into a root node to test it. It works on this xml:
<root>
<Group>
<TimeAdded>2012-04-27T10:23:50.7153613+01:00</TimeAdded>
<GroupName>Group</GroupName>
<GroupHeader>Header</GroupHeader>
<GroupMessages>
<Message>
<MessageID>1</MessageID>
<GroupMessage>Message</GroupMessage>
<MessageGroup/>
</Message>
</GroupMessages>
</Group>
<Group>
<TimeAdded>2012-04-27T10:23:50.7153613+01:00</TimeAdded>
<GroupName>Group</GroupName>
<GroupHeader>Header</GroupHeader>
<GroupMessages>
<Message>
<MessageID>1</MessageID>
<GroupMessage>Message</GroupMessage>
<MessageGroup/>
</Message>
</GroupMessages>
</Group>
</root>