/// <summary>
/// Gets a XmlReaderSettings from a XmlPeekSettings
/// </summary>
/// <returns>The xml reader settings.</returns>
/// <param name="settings">Additional settings to tweak Xml Peek behavior.</param>
private static XmlReaderSettings GetXmlReaderSettings(XmlPeekSettings settings)
{
var xmlReaderSettings = new XmlReaderSettings();
xmlReaderSettings.DtdProcessing = (DtdProcessing)settings.DtdProcessing;
return(xmlReaderSettings);
}
/// <summary>
/// Gets the value of a target node.
/// </summary>
/// <returns>The value found at the given XPath query (or the first, if multiple eligible nodes are found).</returns>
/// <param name="source">The source xml to transform.</param>
/// <param name="xpath">The xpath of the nodes to set.</param>
/// <param name="settings">Additional settings to tweak Xml Peek behavior.</param>
private static string XmlPeek(XmlReader source, string xpath, XmlPeekSettings settings)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (string.IsNullOrWhiteSpace(xpath))
{
throw new ArgumentNullException(nameof(xpath));
}
if (settings == null)
{
throw new ArgumentNullException(nameof(settings));
}
var document = new XmlDocument();
document.PreserveWhitespace = settings.PreserveWhitespace;
document.Load(source);
var navigator = document.CreateNavigator();
var namespaceManager = new XmlNamespaceManager(navigator.NameTable);
foreach (var xmlNamespace in settings.Namespaces)
{
namespaceManager.AddNamespace(xmlNamespace.Key /* Prefix */, xmlNamespace.Value /* URI */);
}
var node = navigator.SelectSingleNode(xpath, namespaceManager);
return(node?.Value);
}
public static string XmlPeek(this ICakeContext context, FilePath filePath, string xpath, XmlPeekSettings settings)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (filePath == null)
{
throw new ArgumentNullException(nameof(filePath));
}
if (settings == null)
{
throw new ArgumentNullException(nameof(settings));
}
var file = context.FileSystem.GetFile(filePath);
if (!file.Exists)
{
throw new FileNotFoundException("Source File not found.", file.Path.FullPath);
}
using (var fileStream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None))
using (var xmlReader = XmlReader.Create(fileStream, GetXmlReaderSettings(settings)))
{
var xmlValue = XmlPeek(xmlReader, xpath, settings);
if (xmlValue == null && !settings.SuppressWarning)
{
context.Log.Warning("Warning: Failed to find node matching the XPath '{0}'", xpath);
}
return(xmlValue);
}
}
