javascript - Express node.js - Requesting JSON, processing it asyncronously -

with node.js app, i'm getting json data spreadsheet api. returns json of following.

{      "status":200,    "success":true,    "result":[         {            "dribbble":"a",          "behance":"",          "blog":"http://blog.invisionapp.com/reimagine-web-design-process/",          "youtube":"",          "vimeo":""       },       {            "dribbble":"",          "behance":"",          "blog":"http://creative.mailchimp.com/paint-drips/?_ga=1.32574201.612462484.1431430487",          "youtube":"",          "vimeo":""       }    ] } 

it's dummy data 1 thing that, need process values (blog urls) under blog differently. blog url, need open graph data i'm using module called open-graph-scraper

with data.js i'm getting whole json , it's available in route index.js data i'm processing data checking blog column. if it's match, loop values (blog urls) through open-graph-scraper module.

this give me open graph data of each blog url following example json.

{  data:     { success: 'true',          ogimage: 'http://davidwalsh.name/wp-content/themes/punky/images/logo.png',          ogtitle: 'david walsh - javascript, html5 consultant',          ogurl: 'http://davidwalsh.name/',          ogsitename: 'david walsh blog',          ogdescription: 'david walsh blog features tutorials mootools, jquery, dojo, javascript, php, css, html5, mysql, , more!' },       success: true  } 

so goal pass blog json separate data main json , put in render separate object it's available in view 2 separate json. i'm not sure if approach getblogdata correct. i'm not sure if processing data thing in router file. appreciate directions.

index.js

var ogs = require('open-graph-scraper');  var data = require('../lib/data.js');  data( function(data) {      var getblogdata = function (callback) {          var blogurl = [];          if (data.length > 0) {               var columnsin = data[0];               for(var key in columnsin) {                  if (key === 'blog') {                     for(var = 0; < data.length; i++) {                         blogurl += data[i][key];                     }                 }                }         };          ogs({              url: blogurl          }, function(er, res) {              console.log(er, res);              callback(res);         });     }      getblogdata( function (blogdata) {        //i want make blogdata available in render below           don't know how     });      router.get('/', function(req, res, next) {       res.render('index', {          title: 'express',          data: data       });     }); }); 

data.js (my module gets json data)

module.exports = function(callback) {      var request = require("request")     var url = "http://sheetsu.com/apis/94dc0db4"      request({         url: url,         json: true     }, function (error, response, body) {          if (!error && response.statuscode === 200) {              var results = body["result"];             callback(results)          }     })  } 

the problem you'll have if getblogdata asynchronously (and should, don't want client waiting around data return), time data res.render have been called. can't call res.render again, have 2 options come mind:

1. you query individual blog data client. result in more back-and-forth between client , server strategy if have lot of entries in initial data want display small number.
2. you use websockets send data client retrieve it. express.io easy way this.