Files
Umbraco-CMS/src/Umbraco.Core/Xml/XmlNodeExtensions.cs
2013-03-21 08:54:25 -01:00

100 lines
4.7 KiB
C#

using System.Collections.Generic;
using System.Linq;
using System.Xml;
using System.Xml.XPath;
// source: mvpxml.codeplex.com
namespace Umbraco.Core.Xml
{
internal static class XmlNodeExtensions
{
static XPathNodeIterator Select(string expression, XPathNavigator source, params XPathVariable[] variables)
{
var expr = source.Compile(expression);
var context = new DynamicContext();
foreach (var variable in variables)
context.AddVariable(variable.Name, variable.Value);
expr.SetContext(context);
return source.Select(expr);
}
/// <summary>
/// Selects a list of XmlNode matching an XPath expression.
/// </summary>
/// <param name="source">A source XmlNode.</param>
/// <param name="expression">An XPath expression.</param>
/// <param name="variables">A set of XPathVariables.</param>
/// <returns>The list of XmlNode matching the XPath expression.</returns>
/// <remarks>
/// <para>If <param name="variables" /> is <c>null</c>, or is empty, or contains only one single
/// value which itself is <c>null</c>, then variables are ignored.</para>
/// <para>The XPath expression should reference variables as <c>$var</c>.</para>
/// </remarks>
public static XmlNodeList SelectNodes(this XmlNode source, string expression, IEnumerable<XPathVariable> variables)
{
var av = variables == null ? null : variables.ToArray();
return SelectNodes(source, expression, av);
}
/// <summary>
/// Selects a list of XmlNode matching an XPath expression.
/// </summary>
/// <param name="source">A source XmlNode.</param>
/// <param name="expression">An XPath expression.</param>
/// <param name="variables">A set of XPathVariables.</param>
/// <returns>The list of XmlNode matching the XPath expression.</returns>
/// <remarks>
/// <para>If <param name="variables" /> is <c>null</c>, or is empty, or contains only one single
/// value which itself is <c>null</c>, then variables are ignored.</para>
/// <para>The XPath expression should reference variables as <c>$var</c>.</para>
/// </remarks>
public static XmlNodeList SelectNodes(this XmlNode source, string expression, params XPathVariable[] variables)
{
if (variables == null || variables.Length == 0 || variables[0] == null)
return source.SelectNodes(expression);
var iterator = Select(expression, source.CreateNavigator(), variables);
return XmlNodeListFactory.CreateNodeList(iterator);
}
/// <summary>
/// Selects the first XmlNode that matches an XPath expression.
/// </summary>
/// <param name="source">A source XmlNode.</param>
/// <param name="expression">An XPath expression.</param>
/// <param name="variables">A set of XPathVariables.</param>
/// <returns>The first XmlNode that matches the XPath expression.</returns>
/// <remarks>
/// <para>If <param name="variables" /> is <c>null</c>, or is empty, or contains only one single
/// value which itself is <c>null</c>, then variables are ignored.</para>
/// <para>The XPath expression should reference variables as <c>$var</c>.</para>
/// </remarks>
public static XmlNode SelectSingleNode(this XmlNode source, string expression, IEnumerable<XPathVariable> variables)
{
var av = variables == null ? null : variables.ToArray();
return SelectSingleNode(source, expression, av);
}
/// <summary>
/// Selects the first XmlNode that matches an XPath expression.
/// </summary>
/// <param name="source">A source XmlNode.</param>
/// <param name="expression">An XPath expression.</param>
/// <param name="variables">A set of XPathVariables.</param>
/// <returns>The first XmlNode that matches the XPath expression.</returns>
/// <remarks>
/// <para>If <param name="variables" /> is <c>null</c>, or is empty, or contains only one single
/// value which itself is <c>null</c>, then variables are ignored.</para>
/// <para>The XPath expression should reference variables as <c>$var</c>.</para>
/// </remarks>
public static XmlNode SelectSingleNode(this XmlNode source, string expression, params XPathVariable[] variables)
{
if (variables == null || variables.Length == 0 || variables[0] == null)
return source.SelectSingleNode(expression);
return SelectNodes(source, expression, variables).Cast<XmlNode>().FirstOrDefault();
}
}
}