unbound action which returns largebinary

[ilhanburak]

Hello,

If I add custom handler to Read entity with mediatype property, i can return binary result to client.

entity Books : managed {
  key ID : Integer;
  descr  : localized String(1111);
  genre  : Association to Genres;
  stock  : Integer;
  price  : Decimal;
  currency : Currency;
  image : LargeBinary @Core.MediaType : 'image/png';
}

And implementation of read event.

this.on("READ", Books, async (req, next) => {

      const url = req._.req.path
      if (url.includes('image')) {

        let file = fs.readFileSync(path.resolve(__dirname, '../image.png'));
        const readable = new Readable()
        const result = new Array()
        readable.push(file)
        readable.push(null)
        result.push({
          value: readable,
          $mediaContentType: "image/png",
          $mediaContentDispositionFilename: "image.png"
        })
        return result
      } else
        await next();
    })

But if I use same method in unbound action, response is not a file, it's json with following content. ( After renaming .png to txt)
{"@odata.context":"$metadata#CatalogService.return_CatalogService_downloadAllImages"}

Unbound action definition

function downloadAllImages()                                                           returns {
   @Core.ContentDisposition.Filename: fileName
   @Core.MediaType                  : mediaType
   value : LargeBinary;
   mediaType : String;
   fileName : String;
 };

Handler of unbound action.

this.on('downloadAllImages', async (req) => {

      let file = fs.readFileSync(path.resolve(__dirname, '../image.png'));
      const readable = new Readable()
      const result = new Array()
      readable.push(file)
      readable.push(null)
      result.push({
        value: readable,
        $mediaContentType: "image/png",
        $mediaContentDispositionFilename: "image.png"
      })
      return result
    })

How can I send file response to client in unbound action ?
Regards.

[renejeglinsky]

Hi @ilhanburak ,
in this repository we handle issue related to documentation. I don't see any reference in your issue where exisiting documentation is linked which might be wrong, insufficient or else.
Overall my impression is, that you would get faster and better support when asking this question in the SAP Community.
Do you agree?