private static string EvalValue(CustomXsltContext customContext, XNode contextNode, string valueOrExpression)
{
// TODO this is quick and dirty
if (valueOrExpression.StartsWith("{") && valueOrExpression.EndsWith("}"))
{
string expression = valueOrExpression.Substring(1, valueOrExpression.Length - 2);
object value = contextNode.XPathEvaluate(expression, customContext);
return ResultToString(value);
}
return valueOrExpression;
}
protected virtual XDocument ApplyMetaTransforms(XDocument workingDoc, CustomXsltContext customContext, IFileProvider provider, TempFileCollection tempFiles)
{
// check for meta-template directives and expand
int metaCount = 0;
XElement metaNode = workingDoc.Root.Elements("meta-template").FirstOrDefault();
while (metaNode != null)
{
if (EvalCondition(customContext, metaNode, this.GetAttributeValueOrDefault(metaNode, "condition")))
{
XslCompiledTransform metaTransform = this.LoadStylesheet(provider,
this.GetAttributeValue(metaNode, "stylesheet"));
XsltArgumentList xsltArgList = new XsltArgumentList();
// TODO this is a quick fix/hack
xsltArgList.AddExtensionObject(Namespaces.Template, new TemplateXsltExtensions(null, null));
var metaParamNodes = metaNode.Elements("with-param");
foreach (XElement paramNode in metaParamNodes)
{
string pName = this.GetAttributeValue(paramNode, "name");
string pExpr = this.GetAttributeValue(paramNode, "select");
try
{
xsltArgList.AddParam(pName,
string.Empty,
workingDoc.XPathEvaluate(pExpr, customContext));
}
catch (XPathException ex)
{
throw new TemplateException(this._templateSourcePath,
paramNode.Attribute("select"),
string.Format(
"Unable to process XPath expression: '{0}'",
pExpr),
ex);
}
}
// this isn't very nice, but I can't figure out another way to get LineInfo included in the transformed document
XDocument outputDoc;
using (MemoryStream tempStream = new MemoryStream())
using (XmlWriter outputWriter = XmlWriter.Create(tempStream, new XmlWriterSettings { Indent = true }))
{
metaTransform.Transform(workingDoc.CreateNavigator(),
xsltArgList,
outputWriter,
new XmlFileProviderResolver(provider));
outputWriter.Close();
// rewind stream
tempStream.Seek(0, SeekOrigin.Begin);
outputDoc = XDocument.Load(tempStream, LoadOptions.SetLineInfo);
// create and register temp file
// this will override the value set in PrepareTemplate in case of template inhertence
// TODO this is a bit hacky, maybe add Template.Name {get;} instead of this._basePath (which could be anything)
string filename = this._basePath + ".meta." + (++metaCount).ToString(CultureInfo.InvariantCulture);
this._templateSourcePath = this.SaveTempFile(tempFiles, outputDoc, filename);
}
TraceSources.TemplateSource.TraceVerbose("Template after transformation by {0}",
this.GetAttributeValue(metaNode, "stylesheet"));
TraceSources.TemplateSource.TraceData(TraceEventType.Verbose, 1, outputDoc.CreateNavigator());
workingDoc = outputDoc;
}
else
{
// didn't process, so remove it
metaNode.Remove();
}
// select next template
metaNode = workingDoc.Root.Elements("meta-template").FirstOrDefault();
}
return workingDoc;
}
private static bool EvalCondition(CustomXsltContext customContext, XNode contextNode, string condition)
{
bool shouldApply;
if (string.IsNullOrWhiteSpace(condition))
shouldApply = true;
else
{
object value = contextNode.XPathEvaluate(condition, customContext);
shouldApply = ResultToBool(value);
}
return shouldApply;
}
private static CustomXsltContext CreateCustomXsltContext(VersionComponent? ignoredVersionComponent)
{
CustomXsltContext xpathContext = new CustomXsltContext();
xpathContext.RegisterFunction(string.Empty, "get-id", new XsltContextAssetIdGetter());
xpathContext.RegisterFunction(string.Empty, "get-version", new XsltContextAssetVersionGetter());
xpathContext.RegisterFunction(string.Empty, "substring-before-last", new XsltContextSubstringBeforeLastFunction());
xpathContext.RegisterFunction(string.Empty, "substring-after-last", new XsltContextSubstringAfterLastFunction());
xpathContext.RegisterFunction(string.Empty, "iif", new XsltContextTernaryOperator());
xpathContext.RegisterFunction(string.Empty, "get-significant-version", new XsltContextAssetVersionGetter(ignoredVersionComponent));
xpathContext.RegisterFunction(string.Empty, "coalesce", new XsltContextCoalesceFunction());
xpathContext.RegisterFunction(string.Empty, "join", new XsltContextJoinFunction());
return xpathContext;
}