using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
namespace LinqToXML
{
public class NewWay
{
/// <summary>
/// Create a sample document
/// </summary>
public static void CreateEmployees()
{
XDocument doc = new XDocument(
// To use a XElement the XDeclaration and XCooment can't be used
//XElement doc = new XElement(
new XDeclaration("1.0", "utf-8", "yes"),
new XComment("A sample xml file"),
new XElement("employees",
new XElement("employee",
new XAttribute("id", 1),
new XAttribute("salaried", "false"),
new XElement("name", "Gustavo Achong"),
new XElement("hire_date", "7/31/1996")),
new XElement("employee",
new XAttribute("id", 3),
new XAttribute("salaried", "true"),
new XElement("name", "Kim Abercrombie"),
new XElement("hire_date", "12/12/1997")),
new XElement("employee",
new XAttribute("id", 8),
new XAttribute("salaried", "false"),
new XElement("name", "Carla Adams"),
new XElement("hire_date", "2/6/1998")),
new XElement("employee",
new XAttribute("id", 9),
new XAttribute("salaried", "false"),
new XElement("name", "Jay Adams"),
new XElement("hire_date", "2/6/1998"))
)
);
Console.WriteLine(doc.ToString());
// The XDeclaration doesn't show up in the console
// window, so save the file for review to prove it
// is there
doc.Save(@"f:\test.xml");
}
/// <summary>
/// Demonstrate the creation of an XElement
/// as an independent element, not tied to
/// a document
/// </summary>
public static void SingleEmployee()
{
XElement employee = new XElement("employee",
new XAttribute("id", 1),
new XAttribute("salaried", "false"),
new XElement("name", "Gustavo Achong"),
new XElement("hire_date", "7/31/1996"));
Console.WriteLine(employee.ToString());
}
/// <summary>
/// Demonstrate loading xml from a file
/// </summary>
public static void LoadEmployees()
{
XElement employees = XElement.Load("../../sample.xml");
Console.WriteLine(employees.ToString());
}
/// <summary>
/// Demonstrate using a namespace with a
/// XML document
/// </summary>
public static void WithNamespace()
{
XNamespace ns = "http://mycompany.com";
XElement doc = new XElement(
new XElement(ns + "employees",
new XElement("employee",
new XAttribute("id", 1),
new XAttribute("salaried", "false"),
// Note here that a namespace is not supplied on these
// elements. This will cause an emoty namespace to be
// included
new XElement("name", "Gustavo Achong"),
new XElement("hire_date", "7/31/1996")),
new XElement(ns + "employee",
new XAttribute("id", 3),
new XAttribute("salaried", "true"),
new XElement("name", "Kim Abercrombie"),
new XElement("hire_date", "12/12/1997")),
new XElement(ns + "employee",
new XAttribute("id", 8),
new XAttribute("salaried", "false"),
new XElement("name", "Carla Adams"),
new XElement("hire_date", "2/6/1998")),
new XElement(ns + "employee",
new XAttribute("id", 9),
new XAttribute("salaried", "false"),
new XElement("name", "Jay Adams"),
new XElement("hire_date", "2/6/1998"))
)
);
Console.WriteLine(doc.ToString());
}
/// <summary>
/// Demonstrate using two namespaces
/// </summary>
public static void WithNamespaceWithPrefix()
{
XNamespace ns1 = "http://mycompany.com";
XNamespace ns2 = "http://somecompany.com";
XElement doc = new XElement(
new XElement(ns1 + "employees",
new XAttribute(XNamespace.Xmlns + "ns1", ns1),
new XElement(ns2 + "employee",
new XAttribute("id", 1),
new XAttribute("salaried", "false"),
new XAttribute(XNamespace.Xmlns + "ns2", ns2),
new XElement(ns2 + "name", "Gustavo Achong"),
new XElement(ns2 + "hire_date", "7/31/1996")),
new XElement(ns2 + "employee",
new XAttribute("id", 3),
new XAttribute("salaried", "true"),
new XAttribute(XNamespace.Xmlns + "ns2", ns2),
new XElement(ns2 + "name", "Kim Abercrombie"),
new XElement(ns2 + "hire_date", "12/12/1997")),
new XElement(ns2 + "employee",
new XAttribute("id", 8),
new XAttribute("salaried", "false"),
new XAttribute(XNamespace.Xmlns + "ns2", ns2),
new XElement(ns2 + "name", "Carla Adams"),
new XElement(ns2 + "hire_date", "2/6/1998")),
new XElement(ns2 + "employee",
new XAttribute("id", 9),
new XAttribute("salaried", "false"),
new XAttribute(XNamespace.Xmlns + "ns2", ns2),
new XElement(ns2 + "name", "Jay Adams"),
new XElement(ns2 + "hire_date", "2/6/1998"))
)
);
Console.WriteLine(doc.ToString());
}
/// <summary>
/// Demonstrate explict conversion of datatypes
/// </summary>
public static void Casting()
{
XElement element1 = new XElement("number", 42);
// It doesn't matter it the value is a string or int
XElement element2 = new XElement("number", "42");
int num1 = (int)element1;
int num2 = (int)element2;
}
/// <summary>
/// Demonstrate iteration of an XML document
/// </summary>
public static void TraverseTree()
{
XDocument doc = CreateEmployeesPrivate();
Console.WriteLine("-- All nodes --");
// Iterate over all nodes
foreach(var node in doc.Nodes())
{
Console.WriteLine(node);
}
Console.WriteLine(Environment.NewLine);
Console.WriteLine("-- XElement nodes --");
// Iterate over the XElement nodes
foreach(var node in doc.Nodes().OfType<XElement>())
{
Console.WriteLine(node);
}
Console.WriteLine(Environment.NewLine);
Console.WriteLine("-- XComment nodes --");
// Iterate over only the XComment nodes
foreach(var node in doc.Nodes().OfType<XComment>())
{
Console.WriteLine(node);
}
Console.WriteLine(Environment.NewLine);
Console.WriteLine("-- Employee name nodes --");
// Iterate over only the XComment nodes
foreach(var node in doc.Elements("employees").Elements("employee").Elements("name"))
{
Console.WriteLine(node);
}
}
/// <summary>
/// Demonstrate create a new XElement from a query
/// </summary>
public static void CreateFromQuery()
{
XDocument doc = CreateEmployeesPrivate();
// Order the employee elements by hire date and select
// the first one as the newest employee
var newElement = doc.Descendants("employee").Select(e => e).OrderBy(e => DateTime.Parse((string)e.Element("hire_date"))).First();
// Create an element from the above query
XElement element = new XElement("newest_hire", newElement);
Console.WriteLine(element);
}
/// <summary>
/// Demonstrate creating a new XElment from a direct query
/// </summary>
public static void Transform()
{
XDocument doc = CreateEmployeesPrivate();
// Use query expression to find all salaried employees
// and create a new XElement with their name(s)
XElement element = new XElement("salaried_employees", from e in doc.Descendants("employee")
where e.Attribute("salaried").Value == "true"
select new XElement("employee",
new XElement(e.Element("name")) )
);
Console.WriteLine(element);
}
#region Private methods
/// <summary>
/// Private method to create an XML document
/// for use in other methods.
/// This is seperate from the CreateEmployees static
/// method to allow the former to be manipulated for demo
/// purposes, whithout effecting other methods
/// </summary>
/// <returns></returns>
private static XDocument CreateEmployeesPrivate()
{
XDocument doc = new XDocument(
new XDeclaration("1.0", "utf-8", "yes"),
new XComment("A sample xml file"),
new XElement("employees",
new XElement("employee",
new XAttribute("id", 1),
new XAttribute("salaried", "false"),
new XElement("name", "Gustavo Achong"),
new XElement("hire_date", "7/31/1996")),
new XElement("employee",
new XAttribute("id", 3),
new XAttribute("salaried", "true"),
new XElement("name", "Kim Abercrombie"),
new XElement("hire_date", "12/12/1997")),
new XElement("employee",
new XAttribute("id", 8),
new XAttribute("salaried", "false"),
new XElement("name", "Carla Adams"),
new XElement("hire_date", "2/6/1998")),
new XElement("employee",
new XAttribute("id", 9),
new XAttribute("salaried", "false"),
new XElement("name", "Jay Adams"),
new XElement("hire_date", "2/6/1998"))
)
);
return doc;
}
#endregion
}
}
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