protected virtual bool TryCapture <T>(IFragmentBuilder parent, Expression node, out T result, out CaptureFragmentContext context) where T : IFragmentBuilder
{
context = new CaptureFragmentContext(parent, this.Query.Clone());
var capture = new CaptureFragmentTarget(context);
this.Push(capture);
try
{
this.Visit(node);
}
finally
{
this.Pop(false);
}
foreach (var expression in context.Expressions)
{
if (expression is T)
{
result = (T)expression;
return(true);
}
}
result = default(T);
return(false);
}
protected virtual T Capture <T>(IFragmentBuilder parent, Expression node, out CaptureFragmentContext context) where T : IFragmentBuilder
{
var expression = default(T);
if (!this.TryCapture <T>(parent, node, out expression, out context))
{
throw new InvalidOperationException(string.Format("Failed to capture fragment of type \"{0}\".", typeof(T).FullName));
}
return(expression);
}
public CaptureFragmentTarget(CaptureFragmentContext context)
: base(context.Parent, context.Graph)
{
this.Context = context;
}
