使用 process.env 更改 Node.js 中 json object 的值

Question

I'm learning Node.js atm and am trying to change the response of an app request, depending on certain parameters. For instance if I set the MESSAGE_STYLE to uppercase I want the value of the (single) key in the json object to become uppercase. However I can't seem to change the object. I'm not reading the value as a string it seems, so to toUpperCase() doesn't work.

After reading this article I tried JSON.parse and then JSON.dump but that didn't work either (unless I did it wrong). Help is much appreciated!

THIS DOESN'T WORK

process.env.MESSAGE_STYLE='uppercase';

app.get('/json', function(req, res){
var response = res.json({
  "message": "Hello json"
});

if(process.env.MESSAGE_STYLE==='uppercase'){
  response.message.toUpperCase();
  return response;
} else {
  return response;
  };
});

BUT THIS DOES

process.env.MESSAGE_STYLE='uppercase';

app.get('/json', function(req, res){

if(process.env.MESSAGE_STYLE==='uppercase'){
  res.json({
  "message": "HELLO JSON"
})
} else {
    res.json({
  "message": "Hello json"
})
  };
});

Answer 1

You have assigned the response object but it needs to be overridden to get your latest changes in response.message attribute.

process.env.MESSAGE_STYLE='uppercase';

app.get('/json', function(req, res){
// Variable assignment as object
var response = {
  "message": "Hello json"
};

if(process.env.MESSAGE_STYLE==='uppercase'){
  //Override message attribute value based on condition
  response.message = response.message.toUpperCase();  
}

return res.json(response);
});