Hello,
I cannot seem to get avro union types to work properly in the c++ codebase
that I pulled from your github repo a couple of weeks ago. I want to
specify that an object attribute can be either null or a string in order to
capture some notion of optional attributes in my json data. However, when
decoding data that actually has a string value for the "optional" attribute
in question, I get the following exception: "Incorrect token in the stream.
Expected: Object start, found String". Here is a small program that
replicates the issue:
std::string schema;
schema += "{";
schema += " \"name\" : \"simple\", ";
schema += " \"type\" : \"record\", ";
schema += " \"fields\" : [ { \"name\" : \"last\", \"type\" : [
\"null\", \"string\"] } ] ";
schema += "}";
std::string value;
value += "{";
value += " \"last\" : \"dog\" ";
value += "}";
std::istringstream schemass(schema);
std::istringstream valuess(value);
avro::ValidSchema cpxSchema;
avro::compileJsonSchema(schemass, cpxSchema);
std::unique_ptr<avro::InputStream> json_is =
avro::istreamInputStream(valuess);
/* JSON decoder */
avro::DecoderPtr json_decoder = avro::jsonDecoder(cpxSchema);
avro::GenericDatum *datum = new avro::GenericDatum(cpxSchema);
try
{
/* Decode JSON to Avro datum */
json_decoder->init(*json_is);
avro::decode(*json_decoder, *datum);
}
catch(const avro::Exception &_e)
{
// throws Incorrect token in the stream. Expected: Object start,
found String
}
Do I need to configure the system in a particular way for this to work, or
does the current implementation simply not support these types of unions.
I sincerely hope someone can help!
All the best,
Svend
