onUpdate.js

import("Workflow_lib");
import("system.vars");
import("system.db");
import("Document_lib");

var id = vars.get("$field.UID");
var parentId = "";
var fileName = vars.get("$field.NAME");
var description = vars.get("$field.DESCRIPTION");
var alias = db.getCurrentAlias();

var bindata = DocumentUtil.getBindataFromUpload(vars.get("$field.BINDATA_UPLOAD"));
if (bindata == ''){
    bindata = vars.get("$field.BINDATA_UPLOAD")
}

var keyword = '';
if(vars.get("$field.IS_MAIN_DOCUMENT") == '1') {
    keyword = 'MAINDOCUMENT';
} 

// Check if bindata is present and execute the corresponding update method
if(bindata != '')
    db.updateBinary(id, parentId, bindata, fileName, description, keyword, alias);
else
    db.updateBinaryMetadata(id, parentId, fileName, description, keyword, alias);

WorkflowSignalSender.updated();