CODEWITHSUNDEEP
node.jsexpress
Hamish
Hamish

Reputation: 1015

Return object from REST call

I'm pretty new at node, so I may be going about this all wrong (if I am, don't be afraid to say) - I'd like to be able to create an object made of data from several different rest servers and return the final object to my calling function. For each rest api I have a function that looks a bit like this:

jobs.js

exports.get_users_jobs = function(options, onResult) {

  var user = options.params.user;

  console.log("Get jobs for user: " + user);

  var optionsget = {
    host: config.jobs_rest_host,
    port: config.jobs_rest_port,
    path: "/jobs3/user/" + user,
    method: "GET",
    headers: {
        'Content-Type': 'application/json'
    }
  };

  var reqGet = http.request(optionsget, function(res) {
    var output = '';

    res.setEncoding('utf-8');

    res.on('data', function(chunk) {
      output += chunk;
    });

    res.on('end', function() {
      var obj = JSON.parse(output);
      onResult.send(res.statusCode, obj);
    });

  });

  reqGet.end();

  reqGet.on('error', function(e) {
    console.error('error: ' + e.message);
  });
};

That works fine when I'm calling it directly from the browser, but now I'd like to call get_users_jobs from another function, take the data and plonk that into my uber object. So I've created something a bit like this (I've only put jobs in there for now, but soon there will be other variables)

users.js

var jobs = require('./jobs.js');

function User (jobs) {
    this.jobs = jobs;
}

User.prototype.jobs = null;

/* lots of stuff that I don't think matters */

jobs_data = jobs.get_cb_users_jobs(req, res);

var u = User(jobs_data);

/* do lots of stuff with u like prepare reports etc */

But all that happens here is my jobs data is output in the browser (which makes sense since I have onResult.send(blah) - how can I construct my get_users_jobs function to just return the data from the rest call?

Thanks in advance to anyone that can help!

Upvotes: 1

Views: 1769

Answers (1)

soulcheck
soulcheck

Reputation: 36767

Instead of passing a response to your get_users_jobs, pass it a callback as a second parameter, something like this:

exports.get_users_jobs = function(options, cb) {

    //...
    //no changes
    //...

  var reqGet = http.request(optionsget, function(res) {

    var output = '';

    res.setEncoding('utf-8');

    res.on('data', function(chunk) {
      output += chunk;
    });


    res.on('end', function() {
      var obj = JSON.parse(output);
      cb(null, {
          status: res.statusCode, 
          data: output
      });
    });

  });

  reqGet.end();

  reqGet.on('error', function(e) {
    cb(err);
  });
};

and then in users.js:

jobs.get_cb_users_jobs(req, function(err, result) {
    if (err) { 
        //handle the error
    } else { 
        //do whatever you want with the result
    }
});

Notice the call to callback inside res.on('data', ...) and res.on('error', ...) - this is a typical node.js callback pattern. You did the same thing, but passed the control to response instead of your own function.

If you still need to pass the result directly to response, add a wrapper function that passes 

 function(err, response) {
     if (err) {
          console.error('error: ' + e.message);
     } else {
          onResult.send(res.statusCode, obj);
     }
 }

as callback parameter to get_users_jobs

Upvotes: 2

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