private static ViewDataInfo EvalComplexExpression(object indexableObject, string expression)
{
foreach (ExpressionPair expressionPair in GetRightToLeftExpressions(expression))
{
string subExpression = expressionPair.Left;
string postExpression = expressionPair.Right;
ViewDataInfo subTargetInfo = GetPropertyValue(indexableObject, subExpression);
if (subTargetInfo != null)
{
if (String.IsNullOrEmpty(postExpression))
{
return(subTargetInfo);
}
if (subTargetInfo.Value != null)
{
ViewDataInfo potential = EvalComplexExpression(subTargetInfo.Value, postExpression);
if (potential != null)
{
return(potential);
}
}
}
}
return(null);
}
/// <summary>Evals.</summary>
///
/// <param name="vdd"> The vdd.</param>
/// <param name="expression">The expression.</param>
///
/// <returns>A ViewDataInfo.</returns>
public static ViewDataInfo Eval(ViewDataDictionary vdd, string expression)
{
//Given an expression "foo.bar.baz" we look up the following (pseudocode):
// this["foo.bar.baz.quux"]
// this["foo.bar.baz"]["quux"]
// this["foo.bar"]["baz.quux]
// this["foo.bar"]["baz"]["quux"]
// this["foo"]["bar.baz.quux"]
// this["foo"]["bar.baz"]["quux"]
// this["foo"]["bar"]["baz.quux"]
// this["foo"]["bar"]["baz"]["quux"]
ViewDataInfo evaluated = EvalComplexExpression(vdd, expression);
return(evaluated);
}
/// <summary>Evals.</summary>
///
/// <param name="expression">The expression.</param>
///
/// <returns>A string.</returns>
public object Eval(string expression)
{
ViewDataInfo info = GetViewDataInfo(expression);
return((info != null) ? info.Value : null);
}
