node and express send json formatted

Question

I'm trying to send formatted json with express.

Here is my code:

var app = express();

app.get('/', function (req, res) {
  users.find({}).toArray(function(err, results){
    // I have try both
    res.send(JSON.stringify(results, null, 4));
    // OR
    res.json(results);
  });
});

I get the json in my browser but it's a string. How can I send it so it's readable in the browser?

JSON is always a string. To get the object back, you have to parse that string on the client side. — Sirko, Sep 20 '15 at 12:40

score 103 · Answer 1 · answered Jan 02 '18 at 14:25

103

try to set the "secret" property json spaces on the Node app.

app.set('json spaces', 2)

This statement above will produce indentation on json content.

answered Jan 02 '18 at 14:25

Alexis Diel

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2

I think JSON.stringify() plus content-type header is the "official" way that one should understand, but this secret property is preferred because it's much cleverer! – Zhiyong Jul 11 '19 at 11:49
Definitely trick of the day ! Combined with `app.use(express.json())` it's much cleaner in code to have `res.json()` instead of `res.send(JSON.stringify(), null, 4)` – Oblx Jul 13 '22 at 19:06
Most convenient method and easy to turn on/off for dev/prod. Documentation: http://expressjs.com/en/4x/api.html#app.set – Ryan Sep 04 '22 at 14:13
is there a way to make it coloured ? – Lucifer Apr 24 '23 at 06:27
@Lucifer, for color, it depends on how you are consuming the endpoint, for example, if you use Google Chrome, you can install an extension to do this – Alexis Diel Apr 25 '23 at 12:09
well I meant from the server side itself. Can my Express app enforce colored json? – Lucifer Apr 26 '23 at 08:19

Bidhan · Accepted Answer · 2015-09-20T12:46:43.440

53

You're going to have to set the Content-Type to application/json like this

app.get('/', function (req, res) {
    users.find({}).toArray(function(err, results){
        res.header("Content-Type",'application/json');
        res.send(JSON.stringify(results, null, 4));
  });
});

edited Sep 20 '15 at 12:46

answered Sep 20 '15 at 12:40

Bidhan

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thanks it works with the stringify way. Please edit your post so it will be more clear and I can validate it – BoumTAC Sep 20 '15 at 12:43

score 7 · Answer 3 · answered Mar 27 '19 at 03:17

7

Use type('json') to set Content-Type and JSON.stringify() for formatting:

var app = express();

app.get('/', (req, res) => {
  users.find({}).toArray((err, results) => {
    res.type('json').send(JSON.stringify(results, null, 2) + '\n');
  });
});

answered Mar 27 '19 at 03:17

Afanasii Kurakin

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score 1 · Answer 4 · answered Aug 25 '21 at 14:41

Sending JSON output as formatted from the server could be undesirable considering resource usage and performance of the server. Especially in production environments.

Instead, you can find a few ways to format the JSON output at client-side.

If you are using Chrome, you can use an extension among JSON Formatter, JSON Viewer, JSONView or others from Chrome web store.

Firefox provides built-in JSON viewer since Firefox 44.

When using curl or wget in a command line or a shell script, you can pipe the result in JSON into jq.

$ curl http://www.warehouse.com/products | jq .

score 0 · Answer 5 · answered Jul 19 '18 at 21:07

0

This should solve your problem

var app = express();
app.set('json spaces', 4)

app.get('/', function (req, res) {
  users.find({}).toArray(function(err, results){
      res.json(JSON.parse(results));
  });
});

answered Jul 19 '18 at 21:07

Manjunath G

49
2

score 0 · Answer 6 · answered Feb 22 '23 at 08:54

For convenience, you can override res.json in a custom middleware that runs before your routes.

To auto-format all JSON responses:

app.use('*', (req, res, next) => {
    res.json = (data) => res.type('json').send(JSON.stringify(data, null, 4))
    next()
})

app.get('/route', (req, res) => res.json({ formatted: true })

To allow custom formatting based on individual routes or other logic:

app.use('*', (req, res, next) => {
    res.json = (...args) => res.type('json').send(JSON.stringify(...args))
    next()
})

app.get('/tabs', (req, res) => res.json({ formatted: 'tabs' }, null, '\t')
app.get('/spaces', (req, res) => res.json({ formatted: 'spaces' }, null, 4)
app.get('/minified', (req, res) => res.json({ formatted: false })

score -2 · Answer 7 · answered Sep 20 '15 at 12:42

-2

Maybe you need to JSON.parse(resp)

answered Sep 20 '15 at 12:42

Jason Livesay

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node and express send json formatted

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