/// <summary>
/// Visits the ConstantExpression.
/// </summary>
/// <param name="node">
/// The expression to visit.
/// </param>
/// <returns>
/// The modified expression, if it or any subexpression was modified; otherwise, returns the original expression.
/// </returns>
protected override Expression VisitConstant(ConstantExpression node)
{
if (node.Type == typeof(GenericField))
{
GenericField value = node.GetValue <GenericField>();
switch (value)
{
case GenericField.ActualType:
sortField = new SortField(Documents.ObjectMappingExtensions.FieldActualType, SortFieldType.STRING, sortDescending);
break;
case GenericField.StaticType:
sortField = new SortField(Documents.ObjectMappingExtensions.FieldStaticType, SortFieldType.STRING, sortDescending);
break;
case GenericField.Source:
sortField = new SortField(Documents.ObjectMappingExtensions.FieldSource, SortFieldType.STRING, sortDescending);
break;
case GenericField.Timestamp:
sortField = new SortField(Documents.ObjectMappingExtensions.FieldTimestamp, SortFieldType.INT64, sortDescending);
break;
default:
Debug.Fail("Unsupported GenericField: " + value);
throw new NotSupportedException(String.Format("Unsupported GenericField: {0}.", value));
}
return(node);
}
return(base.VisitConstant(node));
}
public static object GetValue(this Expression expression)
{
if (expression == null)
{
throw new ArgumentNullException(nameof(expression));
}
switch (expression.NodeType)
{
case ExpressionType.Constant:
{
ConstantExpression constantExpression = expression as ConstantExpression;
if (constantExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(ConstantExpression)}\r\n\t{expression}", nameof(expression));
}
return(constantExpression.GetValue());
}
case ExpressionType.Call:
{
MethodCallExpression methodCallExpression = expression as MethodCallExpression;
if (methodCallExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(MethodCallExpression)}\r\n\t{expression}", nameof(expression));
}
return(methodCallExpression.GetValue());
}
case ExpressionType.Convert:
{
UnaryExpression unaryExpression = expression as UnaryExpression;
if (unaryExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(UnaryExpression)}\r\n\t{expression}", nameof(expression));
}
return(unaryExpression.GetValue());
}
case ExpressionType.MemberAccess:
{
MemberExpression memberExpression = expression as MemberExpression;
if (memberExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(MemberExpression)}\r\n\t{expression}", nameof(expression));
}
return(memberExpression.GetValue());
}
case ExpressionType.New:
{
NewExpression newExpression = expression as NewExpression;
if (newExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(NewExpression)}\r\n\t{expression}", nameof(expression));
}
return(newExpression.GetValue());
}
default:
throw new ArgumentException($"Invalid expression type {expression.NodeType}\r\n\t{expression}", nameof(expression));
}
}
/// <summary>
/// Get the value from an expression.
/// </summary>
/// <param name="expression">The expression to be evaluated.</param>
/// <returns>the value.</returns>
public static object GetValue(this Expression expression, JsonSerializerSettings jsonSerializerSettings)
{
if (expression == null)
{
throw new ArgumentNullException(nameof(expression));
}
switch (expression.NodeType)
{
case ExpressionType.Constant:
{
ConstantExpression constantExpression = expression as ConstantExpression;
if (constantExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(ConstantExpression)}\r\n\t{expression}", nameof(expression));
}
return(constantExpression.GetValue());
}
case ExpressionType.Call:
{
MethodCallExpression methodCallExpression = expression as MethodCallExpression;
if (methodCallExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(MethodCallExpression)}\r\n\t{expression}", nameof(expression));
}
return(methodCallExpression.GetValue(jsonSerializerSettings));
}
case ExpressionType.Convert:
{
UnaryExpression unaryExpression = expression as UnaryExpression;
if (unaryExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(UnaryExpression)}\r\n\t{expression}", nameof(expression));
}
return(unaryExpression.GetValue(jsonSerializerSettings));
}
case ExpressionType.MemberAccess:
{
MemberExpression memberExpression = expression as MemberExpression;
if (memberExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(MemberExpression)}\r\n\t{expression}", nameof(expression));
}
return(memberExpression.GetValue(jsonSerializerSettings));
}
case ExpressionType.New:
{
NewExpression newExpression = expression as NewExpression;
if (newExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(NewExpression)}\r\n\t{expression}", nameof(expression));
}
return(newExpression.GetValue(jsonSerializerSettings));
}
case ExpressionType.Not:
{
UnaryExpression unaryExpression = expression as UnaryExpression;
if (unaryExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(UnaryExpression)}\r\n\t{expression}", nameof(expression));
}
object unaryValue = unaryExpression.GetValue(jsonSerializerSettings);
if (unaryValue == null ||
(unaryValue.GetType() != typeof(bool) && unaryValue.GetType() != typeof(bool?)))
{
throw new ArgumentException($"Invalid type", nameof(expression));
}
return(!((bool)unaryValue));
}
case ExpressionType.Parameter:
{
ParameterExpression parameterExpression = expression as ParameterExpression;
if (parameterExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(ParameterExpression)}\r\n\t{expression}", nameof(expression));
}
throw new ArgumentException($"Invalid expression type {expression.NodeType}\r\n\t{expression}", nameof(expression));
}
case ExpressionType.NewArrayInit:
{
NewArrayExpression newArrayExpression = expression as NewArrayExpression;
if (newArrayExpression == null)
{
throw new ArgumentException($"Expected {nameof(expression)} to be of type {nameof(NewArrayExpression)}\r\n\t{expression}", nameof(expression));
}
return(newArrayExpression.Expressions.Select(_ => _.GetValue(jsonSerializerSettings)).ToArray());
}
default:
throw new ArgumentException($"Invalid expression type {expression.NodeType}\r\n\t{expression}", nameof(expression));
}
}
void HandleSingleBooleanConstant(ConstantExpression node)
{
var val = (bool)node.GetValue();
_sb.Append(val ? "1=1" : "1<1");
}
