protected override Expression VisitMethodCall(MethodCallExpression node)
{
if (node.Method.DeclaringType == typeof(Queryable) &&
node.Method.Name == "Where")
{
var predicate = node.Arguments[1];
Visit(predicate);
return(node);
}
switch (node.Method.Name)
{
case "Contains":
_action = TranslatorAction.Contains;
break;
case "StartsWith":
_action = TranslatorAction.StartsWith;
break;
case "EndsWith":
_action = TranslatorAction.EndsWith;
break;
}
return(base.VisitMethodCall(node));
}
protected override Expression VisitConstant(ConstantExpression node)
{
switch (_action)
{
case TranslatorAction.Default:
_resultStringBuilder.Append($"({node.Value})\"");
break;
case TranslatorAction.Contains:
_resultStringBuilder.Append($"(*{node.Value}*)\"");
break;
case TranslatorAction.StartsWith:
_resultStringBuilder.Append($"({node.Value}*)\"");
break;
case TranslatorAction.EndsWith:
_resultStringBuilder.Append($"(*{node.Value})\"");
break;
default:
throw new NotSupportedException($"Operation '{_action}' is not supported");
}
_action = TranslatorAction.Default;
return(node);
}
public ExpressionToFtsRequestTranslator()
{
_resultStringBuilder = new StringBuilder();
_action = TranslatorAction.Default;
}
