/// <summary>
/// Returns a parsed version of the XPath query by its name. The parsed query does not contain any macros, all macros will be expanded to their respective sequences.
/// </summary>
/// <param name="name">The unique name under which the XPath query is registered in the XPath library.</param>
/// <returns>The parsed version of the XPath query.</returns>
public string GetXPathQuery(string name)
{
Guard.ArgumentNotNullOrEmptyString(name, "name");
XPathQueryInfo queryInfo = this.Queries.Get(name);
if (null == queryInfo || String.IsNullOrEmpty(queryInfo.XPath))
{
throw new ConfigurationErrorsException(String.Format(CultureInfo.InvariantCulture, ExceptionMessages.XPathQueryNotDefined, name));
}
return(queryInfo.ParseQuery(this));
}
/// <summary>
/// Parses the current XPath query in order to expand the prefixed elements with their fully qualified references.
/// </summary>
internal string ParseQuery(XPathQueryLibrary xPathLib)
{
if (null == this.parsedQueryText || !this.parsed)
{
lock (lockObject)
{
if (null == this.parsedQueryText || !this.parsed)
{
string currentXPath = (string)base[XPathQueryProperty];
// Check whether or not the XPath Query Library object has any namespace definitions
if (xPathLib.Namespaces.Count > 0)
{
// Retrieve the list of namespaces along with their defined prefixes
XmlNamespaceManager namespaceManager = xPathLib.Namespaces.NamespaceManager;
// Represents the method that is called each time a regular expression match is found during a Replace method operation.
MatchEvaluator evaluator = new MatchEvaluator(match =>
{
string resolvedNamespace = namespaceManager.LookupNamespace(match.Groups[Resources.NamespaceGroupName].Value);
if (resolvedNamespace != null)
{
// If the XML namespace was found, return a localized version of the XPath query (e.g. *[local-name()='NodeName' and namespace-uri()='FoundNamespace'])
return(String.Format(CultureInfo.InvariantCulture, Resources.XPathQueryTargetElementRef, match.Groups[Resources.NodeNameGroupName].Value, resolvedNamespace));
}
else
{
// If the target XML namespace is not found, simply return the original fully qualified node name.
return(match.Groups[Resources.FullyQualifiedNodeNameGroupName].Value);
}
});
// Replace the XPath query with its parsed version.
currentXPath = nsExpansionExpr.Replace(currentXPath, evaluator);
}
// Perform macro substitution only if at least 1 macro has been found.
if (currentXPath != null && currentXPath.Contains("{$"))
{
// Represents the method that is called each time a regular expression match is found during a Replace method operation.
MatchEvaluator evaluator = new MatchEvaluator(match =>
{
XPathQueryInfo refQueryInfo = xPathLib.Queries.Get(match.Groups[1].Value);
// Check if we found the referenced XPathQueryInfo, also make sure we don't end up with a circular reference.
if (refQueryInfo != null && String.Compare(refQueryInfo.Name, this.Name, false, CultureInfo.InvariantCulture) != 0)
{
return(refQueryInfo.ParseQuery(xPathLib));
}
else
{
return(null);
}
});
// Update the XPath query with its parsed version.
currentXPath = macroSearchExpr.Replace(currentXPath, evaluator);
}
this.parsedQueryText = currentXPath;
this.parsed = true;
}
}
}
return(this.parsedQueryText);
}
