/// <summary> The Context interface which goes out and gets values from the session
/// Expressions use this interface as a means of evaluation.
///
/// We also use this to create a reference to internal variables.
/// </summary>
public virtual Object lookup(Object o)
{
Object result = null;
try
{
// first see if it is an internal property (avoids player calls)
if (o is String && ((String)o)[0] == '$')
{
String key = (String)o;
Object value = null;
try
{
value = m_cache.get_Renamed(key);
}
catch (Exception)
{
}
result = new InternalProperty(key, value);
}
// attempt to resolve to a player variable
else if ((result = resolveToVariable(o)) != null)
{
}
// or value
else if ((result = resolveToValue(o)) != null)
{
}
else
{
throw new NoSuchVariableException(o);
}
// take on the path to the variable; so 'what' command prints something nice
if ((result != null) && result is VariableFacade)
{
((VariableFacade)result).Path = getName();
}
// if the attempt to get the variable's value threw an exception inside the
// player (most likely because the variable is actually a getter, and the
// getter threw something), then throw something here
Value resultValue = null;
if (result is Variable)
{
resultValue = ((Variable)result).getValue();
}
else if (result is Value)
{
resultValue = (Value)result;
}
if (resultValue != null)
{
if (resultValue.isAttributeSet(ValueAttribute.IS_EXCEPTION))
{
String value = resultValue.ValueAsString;
throw new PlayerFaultException(new ExceptionFault(value));
}
}
}
catch (PlayerDebugException)
{
result = null; // null object
}
return(result);
}
