Node js use variable outside main function and set order of functions

Question

Introduction

I have a three functions, each one would feed data into then next. The objective is first to retrieve data then authenticate a API key then finally using the generated API key and data retrieve from the first function post to the API in the third function.

Order

First function function to retrieve data from a post.
Second function gets API key requested from a API.
Third function posts data to the API.

Needed functionality

I need the variables retried in the first function and the API key generated in the second function to be available for use in the third function.

Problems and questions

emailUser is not being found to use in the third function
api_key is not being found in the third function
also the functions need to run in order first, second then third

This all works if I was to insert the data manual but when input the variables it dose not work, I understand that it is because the variables being within the function but how do I fix this, also how do I set the order of the functions ?

Full code

// Grab the packages needs and sets server
//---------------------------------- Grab the packages we need and set variables --------------------------------------------------
// --------------------------------------------------------------------------------------------------------------------------------
var express = require('express');
var request = require('request');
var nodePardot = require('node-pardot');
var bodyParser = require('body-parser');
var app = express();
var port = process.env.PORT || 8080;

// Varibles to use in second and third function
var password = 'password';
var userkey = '6767712';
var emailAdmin = 'admin@admin.com';
// start the server
app.listen(port);
app.use(bodyParser.json()); // support json encoded bodies
app.use(bodyParser.urlencoded({extended: true})); // support encoded bodies
console.log('Server started! At http://localhost:' + port);

// First Retrieve posted data from Front-End
//---------------------------------- Retrieve posted data from Front-End -----------------------------------------------------
// ---------------------------------------------------------------------------------------------------------------------------
// POST http://localhost:8080/api/index
app.post('/api/data', function (req, res) {
    console.log(req.body);
    var Fname = req.body.fname;
    var Lname = req.body.lname;
    var emailUser = req.body.email;
    res.send(Fname + ' ' + Lname + ' ' + emailUser);
});

app.get('/', function (req, res) {
    res.send('hello world, Nothing to see here...');
});

// Second Get Posted variables
//---------------------------------- Now authenticate the api and get api_key -----------------------------------------------------
// --------------------------------------------------------------------------------------------------------------------------------
nodePardot.PardotAPI({
    userKey: userkey,
    email: emailAdmin,
    password: password,
    // turn off when live
    DEBUG: true
}, function (err, client) {
    if (err) {
        // Authentication failed
        // handle error
        console.error("Authentication Failed", err)
    } else {
        // Authentication successful
        // gets api key
        var api_key = client.apiKey;
        console.log("Authentication successful !", api_key);
    }
});

// Third Retrieve posted data from Front-End
//---------------------------------- Send all data to API -----------------------------------------------------
// ------------------------------------------------------------------------------------------------------------
// Set the headers
var headers = {
    'User-Agent':       'Super Agent/0.0.1',
    'Content-Type':     'application/x-www-form-urlencoded'
};

// Configure the request
var options = {
    url: 'https://pi.pardot.com/api/prospect/version/4/do/create/email',
    method: 'POST',
    headers: headers,
    form: {
        'email': emailUser,
        'user_key': userkey,
        'api_key': api_key
    }
};

// Start the request
request(options, function (error, response, body) {
    if (!error && response.statusCode == 200) {
        // Print out the response body
        console.log("error",body)
    }
    else {
        console.log("Sent Data",body);
    }
});

score 1 · Answer 1 · answered Jun 12 '17 at 10:54

best way is using async package (install with npm install async) that is very famous and useful package in npm your functions will be something like this:

var async=require('async');

var handler = function (req,res) {
async.auto
(
 {
  getBody: function (cb, results) {
    var body=req.body;
    //prepare body here then send it to next function  
    cb(null, body)
  },
  getApi: ['getBody', function (results, cb) {
    var preparedBody=results.getBody;
    // get the api here and send it to next function
    var apiKey=getApi()  
    cb(null, {apiKey:apiKey,preparedBody:preparedBody})

  }],
  third: ['getApi', function (results, cb) {
    var preparedBody=results.getApi.preparedBody;
    var apiKey=results.getApi.apiKey;
      // now data are here
      cb(null,true)
  }]
},
function (err, allResult) {
  // the result of executing all functions goes here
}
)
}

Thank you, Still new with node so am learning. Ill implement this and test then let you know. — Beep, Jun 12 '17 at 10:57
thanks, this is a great answer I am just trying to implement it atm — Beep, Jun 12 '17 at 14:25

score 0 · Answer 2 · answered Jun 12 '17 at 11:47

Another way to handle this problem is by allowing the express middleware flow to do those things for you on a separate Router.

I have setup a sample Glitch for your reference using stand in functions to simulate network calls HERE.

In your case, you would have to do something like:

//API route
var express = require('express');
var router = express.Router();

router.post('/data', function (req, res, next) {
    console.log(req.body);
    req.bundledData = {};
    req.bundledData.fname = req.body.fname;
    req.bundledData.lname = req.body.lname;
    req.bundledData.emailUser = req.body.email;
    next();
});
router.use(function(req, res, next){
    nodePardot.PardotAPI({
        userKey: userkey,
        email: emailAdmin,
        password: password,
        // turn off when live
        DEBUG: true
    }, function (err, client) {
         if (err) {
             // Authentication failed
             // handle error
             console.error("Authentication Failed", err)
         } else {
             // Authentication successful
             // gets api key
             req.bundledData.api_key = client.apiKey;
             console.log("Authentication successful !", api_key);
             next();
         }
   });
});

router.use(function(req, res, next){
    // Set the headers
    var headers = {
        'User-Agent':       'Super Agent/0.0.1',
        'Content-Type':     'application/x-www-form-urlencoded'
    };

    // Configure the request
    var options = {
         url: 'https://pi.pardot.com/api/prospect/version/4/do/create/email',
         method: 'POST',
         headers: headers,
         form: {
            'email': emailUser,
            'user_key': userkey,
            'api_key': api_key
         }
    };

    // Start the request
    request(options, function (error, response, body) {
        if (!error && response.statusCode == 200) {
            // Print out the response body
            console.log("error",body)
        }
        else {
            console.log("Sent Data",body);
            //Processing is complete
            res.json({
                success:true,
                body:body
            });
        }
    });
});

hmm, looks neat. going to lunch now but after ill explore both options, thanks. — Beep, Jun 12 '17 at 12:22

Node js use variable outside main function and set order of functions

2 Answers2