Enum in map[string]interface{} does not encode about avro HOT 4 CLOSED

Awesome, thank you @nrwiersma! If anyone else sees this thread, I was able to implement it with:

buffer := &bytes.Buffer{}
_, err = buffer.Write([]byte{0})
if err != nil {...}

// write id in big-endian
err = binary.Write(buffer, binary.BigEndian, uint32(ID))
if err != nil {...}

// encode data
enc := avro.NewEncoderForSchema(schema, buffer)
err = enc.Encode(data)
if err != nil {...}

from avro.

Hi,

in the map[string]interface{} record case, the union must be a map[string]interface{} with the key as the named type. So the following works:

package main

import (
	"fmt"

	"github.com/hamba/avro"
)

func main() {
	schema, err := avro.Parse(`
{
	"type": "record",
	"name": "test", 
	"fields": [
		{"name": "PET", "type": ["null", {"type": "enum", "name": "pet", "symbols": ["dog", "cat"]}]}
	]
}`)
	if err != nil {
		fmt.Print(err)
		return
	}

	inf := map[string]interface{}{
		"PET": map[string]interface{}{
			"pet": "dog",
		},
	}

	_, err = avro.Marshal(schema, inf)
	if err != nil {
		fmt.Printf("could not encode: %v\n", err)
	}
}

I will point out that using maps if a fair bit slower than using structs in the decode case, and more painful in the encode case. I obviously dont understand your use case, but in most cases, structs are the way forward.

Also for kafka I would suggest using a schema registry, the avro/registry client and encoding the schema id into the message (there is a specific format for that). This makes evolving schemas trivial in the future. This use case is the reason I wrote the library to start with.

from avro.

thanks @nrwiersma! that did the trick. Also thank you for pointing me to the avro/registry client. I was about to implement my own and that will save me a lot of time.

Does this library have functions for serializing the schema id with the avro body? I couldn't find any methods to do that. If there isn't, do you know of any docs that are helpful to understand the binary format?

Thanks

from avro.

No worries.

The lib does not handle this step for you, as it is done in different way depending on the use case. The info you need can be found here: https://docs.confluent.io/current/schema-registry/serdes-develop/index.html#wire-format. Really simple to implement.

from avro.