private SessionStateScope <T> GetScope(ScopeSpecifiers specifier)
{
//if the local scope is meant, return this instance itself
if (specifier == ScopeSpecifiers.Local || specifier == ScopeSpecifiers.Private)
{
return(this);
}
var candidate = this;
//otherwise it's a global or script scope specifier
if (specifier == ScopeSpecifiers.Global || specifier == ScopeSpecifiers.Script)
{
while (candidate.ParentScope != null)
{
if (candidate.IsScriptScope && specifier == ScopeSpecifiers.Script)
{
return(candidate);
}
candidate = candidate.ParentScope;
}
//found the scope without a parent: the global scope
return(candidate);
}
throw new ArgumentException(String.Format("Invalid scope specifier \"{0}\"", specifier));
}
static private bool ValidateScopeSpecifier(string specifier, bool numberAllowed)
{
int scopeLevel = -1;
//first try to interprete it as an int. if we don't do this, the enums TryParse method will misinterpret it
if (int.TryParse(specifier, out scopeLevel) && (scopeLevel < 0 || !numberAllowed))
{
return(false);
}
ScopeSpecifiers scopeSpecifier;
if (!ScopeSpecifiers.TryParse(specifier, true, out scopeSpecifier))
{
return(false);
}
return(true);
}
private SessionStateScope <T> GetScope(string specifier, bool numberAllowed,
SessionStateScope <T> fallback = null)
{
int scopeLevel = -1;
if (String.IsNullOrEmpty(specifier))
{
return(fallback);
}
SessionStateScope <T> candidate = this;
//check if the specifier is a number before trying to interprete it as enum
if (int.TryParse(specifier, out scopeLevel))
{
//sometimes a number specifies the relative scope location, but in some contexts this isn't allowed
//this has to happen *after* trying to parse them as e.g. "0" would be a parsable enum value!
if (!numberAllowed || scopeLevel < 0)
{
throw new ArgumentException("Invalid scope specifier");
}
for (var curLevel = scopeLevel; curLevel > 0; curLevel--)
{
//make sure we can proceed looking for the next scope
candidate = candidate.ParentScope;
if (candidate == null)
{
throw new ArgumentOutOfRangeException("Exceeded the maximum number of available scopes");
}
}
return(candidate);
}
//it's not a (positive) number, let's check if it's a named scope
ScopeSpecifiers scopeSpecifier;
if (!ScopeSpecifiers.TryParse(specifier, true, out scopeSpecifier))
{
throw new ArgumentException(String.Format("Invalid scope specifier \"{0}\".", specifier));
}
return(GetScope(scopeSpecifier));
}
