B4J Code Snippet Python B4XSerializator

If you ever need to send B4X objects from Python service to a B4X app/service or vice versa, this might be helpful. By using the opensource code of B4J and B4A on GitHub, along with some assistance from ChatGPT o1 model, I created a Python class to make it possible.

Yes, you should be using JSON or keep concerns separated, B4X objects for B4X clients or python with existing industry standards. But since it is possible, why not, at least for testing ideas.

Short example:
[CODE lang="python" title="python - B4XSerializator"]from B4XSerializator import B4XSerializator
serializer = B4XSerializator()
my_dict = {...}
bytes_data = serializer.convert_object_to_bytes(my_dict)[/CODE]


Full example:

Spoiler: Full example

The following is a Flask server that serves a B4X map at the /test endpoint, along with a B4J client that requests this object by calling the API.
[CODE lang="python" title="Flask app.py"]from flask import Flask, Response
from B4XSerializator import B4XSerializator

app = Flask(__name__)


@app.route('/test', methods=['GET'])
def test_b4x_serializator():
serializer = B4XSerializator()
my_dict = {
"key1": "value1",
"key2": False,
"testKey": 123,
"nestedList": [1, 2, 3],
"nestedDict": {"innerKey": "innerValue"},
"byteData": b'\x00\x01\x02',
"floatVal": 3.14,
"longInt": 1234567890123456789,
"shortInt": 12345,
"byteInt": -128,
"nullValue": None
}
bytes_data = serializer.convert_object_to_bytes(my_dict)

# Return the bytes as a response
return Response(bytes_data, content_type='application/octet-stream')


if __name__ == '__main__':
app.run(debug=True)[/CODE]

[CODE lang="b4x" title="B4J Test Client"]Sub AppStart (Args() As String)
Log("Hello world!!!")
Dim j As HttpJob
j.Initialize("", Me)
j.Download("http://localhost:5000/test")
StartMessageLoop
End Sub

Sub JobDone(j As HttpJob)
Log("Job succes: "&j.Success)
Dim ret As Map
ret.Initialize
If j.Success Then
Try
Dim ser As B4XSerializator
Dim respMap As Map = ser.ConvertBytesToObject(Bit.InputStreamToBytes(j.GetInputStream))
Log(respMap)

For Each k As String In respMap.Keys
If respMap.Get(k) = Null Then
Log(k & ": is null")
Else
Log(k & ": " & GetType(respMap.Get(k)))
End If

Next

Catch
Log(LastException)
End Try
End If
StopMessageLoop
End Sub[/CODE]

DISCLAIMER: This has only been tested briefly in a local environment and has not yet been tested in production.