CODEWITHSUNDEEP
javascriptnode.jsexpress
LJ Wadowski
LJ Wadowski

Reputation: 6720

Use Express.js endpoints with promises

I am trying to use express with promises but I can't make it work. when I uncomment (1) I can set response as 200, but whatever I try to set as response in promise (2,3,4) It always returns 401

I can console.log data in then so promise is surely resolving but I believe that 401 is send because function doesn't wait for promise to be resolved is that right?

What I'm doing wrong and how I can set response from promise?

Thanks in advance!

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

  //res.json(200, {}); return; --> (1) gives expected 200 

  tree.getData(req.param('ids'))
     .then(function (data) { 
         // console.log('data'); --> (2) logs requested array of data
         //return res.json(200,{}); --> (3) gives 401
         return res.send(data); // --> (4) gives 401
     }).fail(function (err) {
         // never goes here
         console.log(err);
         return res.json(550, err);
     });
});

Upvotes: 2

Views: 3652

Answers (1)

peteb
peteb

Reputation: 19418

You need to add a return before tree.getData to return the promise and its result. An A+ Promise has catch() not fail()

Also when setting a status code in Express you need to use res.status().send() not res.send(status, data) Express res.send() Docs

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

  return tree.getData(req.param('ids'))
     .then(function (data) { 
         return res.status(200).send(data)
     }).catch(function (err) {
         // never goes here
         console.log(err);
         return res.status(550).json(err);
     });
});

Upvotes: 5

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