///<inheritdoc/>
public override MultiFilter Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
{
if (reader.TokenType != JsonTokenType.StartObject)
{
throw new JsonException("Multifilter json must start with '{'.");
}
reader.Read();
if (reader.TokenType != JsonTokenType.PropertyName || MultiFilter.LogicJsonPropertyName != reader.GetString())
{
throw new JsonException($@"Expected ""{MultiFilter.LogicJsonPropertyName}"" property.");
}
reader.Read();
FilterLogic logic = reader.GetString()?.ToLowerInvariant() switch
{
"and" => FilterLogic.And,
"or" => FilterLogic.Or,
object value => throw new JsonException(@$ "Unexpected " "{value}" " value for " "{MultiFilter.LogicJsonPropertyName}" " property."),
null => throw new JsonException(@$ "Unexpected " "null" " value for " "{MultiFilter.LogicJsonPropertyName}" " property.")
};
IList <IFilter> filters = new List <IFilter>();
if (reader.Read() && (reader.TokenType != JsonTokenType.PropertyName || MultiFilter.FiltersJsonPropertyName != reader.GetString()))
{
throw new JsonException($@"Expected ""{MultiFilter.FiltersJsonPropertyName}"" property.");
}
reader.Read();
if (reader.TokenType != JsonTokenType.StartArray)
{
throw new JsonException(@"Expected ""["".");
}
reader.Read();
// We are about to try parsing the JSON to get either a Filter or a MultiFilter.
// We store a copy of the original reader in case the parsing process fails.
Utf8JsonReader readerCopy = reader;
while (reader.TokenType != JsonTokenType.EndArray)
{
long position = reader.TokenStartIndex;
try
{
filters.Add(_filterConverter.Read(ref reader, typeof(Filter), options));
}
catch
{
// The json is not a Filter so we need to go back to where the parsing was performed
// and try to get a MultFilter instead
// 1. The copyReader position is moved to where the original parser were before failing
while (readerCopy.TokenStartIndex < position)
{
readerCopy.Read();
}
// 2. Try to parse the Json and get a MultiFilter.
filters.Add(Read(ref readerCopy, typeof(MultiFilter), options));
// The parsing was a success -> we move the reader to the continue the parsing process
while (reader.TokenStartIndex < readerCopy.TokenStartIndex)
{
reader.Read();
}
reader.Read(); // Advances the reader until the next token
}
}
reader.Read();
if (reader.TokenType != JsonTokenType.EndObject)
{
throw new JsonException(@"Expected ""}"".");
}
return(new MultiFilter
{
Logic = logic,
Filters = filters
});
}