q-io: how to read response.body JSON object using Promises?

Question

I need to make an http request from one server to another server.

The server that will handle this request will just return a JSON Array of objects:

app.get('/array', function (req, res) {
  console.log('GET request received!');
  var response_array = [
    {
      value: 1234
    },
    {
      value: 1234
    },
    {
      value: 55
    }
  ];

  res.send(response_array);
});

I am using q-io to send the http request to that GET method /array and obtain the array:

var _getArray = function(externalUrl) {
  var request = {
    method: "GET",
    url: externalUrl
  };

  return HTTP.request(request)
    .then(function(response) {
      // I need to return the Array inside the body (a Promise) to
      // iterate on it later
      return response.body.read(); // but .read() returns a Buffer
    });
}

Both servers work right, as the request is correctly sent and received from one to another, and also the response.

The issue I have is that I am not achieving to obtain the JSON Array - as read() returns a Buffer and just response.body doesn't return the Array (as the docs say, it returns a representation of a readable stream)... how can I handle this properly to obtain the Array correctly with Promises?

I think you don't need to read(), just use `return response.body` — Zohaib Ijaz, Jan 28 '16 at 18:59
@ZohaibIjaz no, that doesn't return the Array, it returns the [body Object](http://documentup.com/kriskowal/q-io#body) which as the docs say, it is **a representation of a readable stream, either for the content of a request or a response. It is implemented as a Q-IO reader.** — charliebrownie, Jan 28 '16 at 19:04
@Bergi thank you, that was actually what I was looking for, but didn't realize I could put it that way! Post an answer and I'll mark it as correct. — charliebrownie, Jan 28 '16 at 19:37
I wasn't sure whether it's working because you said it's a promise for a *buffer*, not a string. But maybe it gets casted just fine... — Bergi, Jan 28 '16 at 19:40
yeah, the docs about `read()` say so: **returns a promise for the entire body as a string or a buffer.**! thank you! — charliebrownie, Jan 28 '16 at 19:42

score 2 · Accepted Answer · answered Jan 28 '16 at 19:41

If you can get a promise for the body content of the response, you can get a promise for the JSON payload from that by passing it through JSON.parse:

return HTTP.request(request)
  .then(function(response) { return response.body.read() })
  .then(JSON.parse);

score 0 · Answer 2 · answered Jan 28 '16 at 19:08

0

from the docs, https://github.com/kriskowal/q-io#body

it seems that you have to use forEach to get all items

answered Jan 28 '16 at 19:08

Zohaib Ijaz

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but forEach seems to use callbacks, I want to return a promise – charliebrownie Jan 28 '16 at 19:09

q-io: how to read response.body JSON object using Promises?

2 Answers2