private static QueryParameterIdentity GetParameterIdentity(TypeMapping mapping,
Expression <Func <ParameterContext, object> > accessor, QueryParameterBindingType bindingType)
{
Expression operand;
var expression = accessor.Body;
// Strip cast to object
if (expression.NodeType == ExpressionType.Convert)
{
expression = ((UnaryExpression)expression).Operand;
}
// Check for closure member access
if (expression.NodeType != ExpressionType.MemberAccess)
{
return(null);
}
var memberAccess = (MemberExpression)expression;
operand = memberAccess.Expression;
if (operand == null || !operand.Type.IsClosure())
{
return(null);
}
var fieldName = memberAccess.Member.Name;
// Check for raw closure
if (operand.NodeType == ExpressionType.Constant)
{
var closureObject = ((ConstantExpression)operand).Value;
return(new QueryParameterIdentity(mapping, closureObject, fieldName, bindingType));
}
// Check for parameterized closure
if (operand.NodeType == ExpressionType.Call)
{
var callExpression = (MethodCallExpression)operand;
if (string.Equals(callExpression.Method.Name, nameof(ParameterContext.GetValue), StringComparison.Ordinal))
{
operand = callExpression.Object;
if (operand != null && WellKnownOrmTypes.ParameterContext == operand.Type)
{
operand = callExpression.Arguments[0];
}
}
var isParameter = operand != null && operand.NodeType == ExpressionType.Constant;
if (isParameter)
{
var parameterObject = ((ConstantExpression)operand).Value;
return(new QueryParameterIdentity(mapping, parameterObject, fieldName, bindingType));
}
}
return(null);
}
private QueryParameterBinding RegisterParameterBinding(TypeMapping mapping,
Expression <Func <ParameterContext, object> > accessor, QueryParameterBindingType bindingType)
{
QueryParameterBinding result;
var identity = GetParameterIdentity(mapping, accessor, bindingType);
if (identity == null)
{
result = new QueryParameterBinding(mapping, accessor.CachingCompile(), bindingType);
otherBindings.Add(result);
return(result);
}
if (bindingsWithIdentity.TryGetValue(identity, out result))
{
return(result);
}
result = new QueryParameterBinding(mapping, accessor.CachingCompile(), bindingType);
bindingsWithIdentity.Add(identity, result);
return(result);
}
