Send an image as a binary from a REST Service, as %Stream.GlobalBinary or %Stream.FileBinary;

Question

Yone Moreno · Jan 28, 2021

Hello,

We would need some help,

Our aim is to send an image as binary data using a REST Service

Currently we do the following:

1 We get from the external system a binary image in our REST Operation

2 We encode it to Base64

set linea=""
    while (tResponse.Data.AtEnd = 0) {
        set linea = linea_$system.Encryption.Base64Encode(tResponse.Data.Read(57))
    }

3 We send it to the Process in a Response Message:

Class Mensajes.Response.miSCS.ConsultarImagen Extends Ens.Response
{

Property resultado As %Boolean;

Property informacion As %String(MAXLEN = "");

Property binario As %Stream.GlobalBinary;

// Property binario As %Stream.FileBinary;

// Property binario As %GlobalCharacterStream;

// Property binario As %Stream.TmpCharacter;

Property error As EsquemasDatos.Seguridad.Error;

4 The Process takes kindly the Base64 and converts it into a Binary:

set binario = $system.Encryption.Base64Decode(response.informacion)
 
set response.informacion = binario

5 Our REST Service gets the Process response:

//Enviamos al Proceso
        #dim objetoSalida as Mensajes.Response.miSCS.ConsultarImagen
        set tSC = ..SendRequestSync("miSCS",objetoEntrada,.objetoSalida)

6 It writes the binary saved in "objetoSalida.informacion" to the binary property "objeto.binario"

       do objetoSalida.binario.Write(objetoSalida.informacion)

        $$$LOGINFO("objetoSalida.binario: "_objetoSalida.binario.Read())
        do objetoSalida.binario.Rewind()
        
        
        set objetoSalida.informacion = ""

7 Here comes the challenge:

When we convert the Object to JSON, it outputs "binario" the binary data, as "null":

set tSC = claseAux.%WriteJSONStreamFromObject(.pOutput,.objetoSalida,,,,"aeloqtuw")
        
        
$$$LOGINFO("pOutput.Read(): "_pOutput.Read())
do pOutput.Rewind()

When we observe the Message Viewer we see the following traces:

1 Before, we see objetoSalida.binario binary data, the image: