_node-js-creating-a-simple-jsonp-api-with-node-js-and-mongodb.md

Code Examples for my Blog Post: Creating a Simple JSONP API with Node.js and MongoDB

example-1-A.js

{
  "name": "NodeJS-JSONP-Example",
  "version": "0.1.0",
  "description": "A simple Node.js application that provides JSONP services",
  "main": "app.js",
  "engines" : { 
      "node" : "0.8",
      "npm" : ">=1.1"
  },
  "author": "Kevin Chisholm",
  "license": "MIT",
  "dependencies": {
    "express": "3.1.0",
    "mongoose": "3.5.7"
  }
}

example-1-B.js

sudo npm install

example-2.js

//declare the variables that we will need
var
http = require ('http'),
express = require('express'),
app = express(),
url = require('url'),
mongoose = require ("mongoose"),
dbConnString = 'mongodb://localhost/myMongooseDb',
salesSchema = null,
salesMember = null,
utils = {},//stub, will be etended later
initApp = function(){
  //create the http server and start it
  http.createServer(app).listen(app.get('port'),function(){
    //a message to indicate a successful startup of the http server
    console.log('Your Node.js application is listening on port #: ' + app.get('port'));
  });
};

example-3.js

//database implementation

//connect to the database
mongoose.connect(dbConnString,function(err, res){
  if (err){
    console.log ('ERROR connecting to: ' + dbConnString + '! ' + err);
  } else {
    console.log ('Successfully connected to: ' + dbConnString);
  }
});

//define the schema to use
salesSchema = new mongoose.Schema({
  name: {
    first: String,
    last: String
  },
  phone: String
});

//define the data model, using the schema that we just created
salesMember = mongoose.model('Sales', salesSchema);

//express module implementation

//set the port to 5000
app.configure(function(){
  app.set('port',5000);
});

example-4.js

//default
app.get("/",function(req,res){
  res.writeHead(200, {'Content-Type': 'text/html'});
  var str = '<h1>Welcome to your simple JSONP Service</h1>'
  + '<b><a href="/json">View JSON Data</a>   <a href="/json/delete">Delte all JSON Data</a></b>'
  + '<p><b>To make a JSONP call:</b> /json?callback=CALLBACKNAME</p>'
  + '<p><b>To add a user:</b> /addUser?fname=FIRSTNAME&amp;lname=LASTNAME&amp;phone=PHONENUMBER</p>';

  //end the request with the home page html
  res.end(str);
})

//delte all data in the database
app.get("/json/delete",function(req,res){
  //we'll need the response object and the data model
  utils.deleteAllData(res,salesMember);
})

example-5.js

//respond to request for /json
app.get("/json",function(req,res){
  //return every record in the database
  salesMember.find({}).exec(function (err, result) {
    var str = null;

    if (!err) {
    //stringify the database search result
    str = JSON.stringify(result, undefined, 2);

    //if a json callback was provided in the query string
    if(utils.isJsonCallback(req)){
      //wrap the json data with the named callbacck
      str = utils.wrapDataInCallback(req,str);
    };

    //deliver the json
    res.writeHead(200, {'Content-Type': 'application/json'});
      res.end(str);
    } else {
      res.end('Error in first query. ' + err)
    };
  });
});

example-6.js

//add user 
app.get("/addUser",function(req,res){
  var
  str = '',
  menu = '<br /><br /><b><a href="/">Home</a>   <a href="/json">View JSON Data</a></b>',
  url_parts = url.parse(req.url, true),
  query = url_parts.query,
  fname = query.fname,
  lname = query.lname,
  phone = query.phone,

  //add a new document to the collection
  newUser = new salesMember ({
    name: { first: fname, last: lname },
    phone: phone
  });

  //save the new document
  newUser.save(function (err) {
    if (err) console.log ('Error on save!')
  });

  //prepare the response
  res.writeHead(200, {'Content-Type': 'text/html'});

  str = ''
      + '<h1>New User Added!</h1><b>First Name -></b> ' + fname
      + '<br /><br /><b>Last Name -></b> ' + lname
      + '<br /><br /><b>Phone -></b> ' +  phone
      + '<br /><br /><b>This user\'s id is:</b> ' + newUser._id
      + menu;

  //send the response
  res.end(str);
});

example-7.js

//returns the name of the JSON callback, if there is one
utils.getJsonCallbackName = function(req){
  var url_parts = url.parse(req.url, true),
  query = url_parts.query;

  if(!url_parts.query || !url_parts.query.callback){return false};

  return url_parts.query.callback;
};

//takes the passed-in string and returns it
//wrapped in the callback name
utils.wrapDataInCallback = function(req,str){
  var
  start = utils.getJsonCallbackName(req) + '(',
  end = ')';

  return start + str + end;
};

//returns true if the query string contains a "callback" parameter
utils.isJsonCallback = function(req){
  var retVal = utils.getJsonCallbackName(req);

  if(retVal){return true};

  return false;
};

//deletes all data in the passed-in model
utils.deleteAllData = function(res,model){
  var successMessage = ''
  + '<h1 style="color:red">All data has been deleted from the database!</h1>'
  + '<b><a href="/">Home</a></b>';

  //delete all data
  model.remove({}, function(err) {
    if (err) {
      console.log ('There was an error deleting the old data.');
    } else  {
      console.log ('Successfully deleted the old data.');
    res.end(successMessage);
    } 
  });
};

//start the application
initApp();

example-8.js

//declare the variables that we will need
var
http = require ('http'),
express = require('express'),
app = express(),
url = require('url'),
mongoose = require ("mongoose"),
dbConnString = 'mongodb://localhost/myMongooseDb',
salesSchema = null,
salesMember = null,
utils = {},//stub, will be etended later
initApp = function(){
  //create the http server and start it
  http.createServer(app).listen(app.get('port'),function(){
    //a message to indicate a successful startup of the http server
    console.log('Your Node.js application is listening on port #: ' + app.get('port'));
  });
};

//database implementation

//connect to the database
mongoose.connect(dbConnString,function(err, res){
  if (err){
    console.log ('ERROR connecting to: ' + dbConnString + '! ' + err);
  } else {
    console.log ('Successfully connected to: ' + dbConnString);
  }
});

//define the schema to use
salesSchema = new mongoose.Schema({
  name: {
    first: String,
    last: String
  },
  phone: String
});

//define the data model, using the schema that we just created
salesMember = mongoose.model('Sales', salesSchema);

//express module implementation

//set the port to 5000
app.configure(function(){
  app.set('port',5000);
});

//default
app.get("/",function(req,res){
  res.writeHead(200, {'Content-Type': 'text/html'});
  var str = '<h1>Welcome to your simple JSONP Service</h1>'
  + '<b><a href="/json">View JSON Data</a>   <a href="/json/delete">Delte all JSON Data</a></b>'
  + '<p><b>To make a JSONP call:</b> /json?callback=CALLBACKNAME</p>'
  + '<p><b>To add a user:</b> /addUser?fname=FIRSTNAME&lname=LASTNAME&phone=PHONENUMBER</p>';

  //end the request with the home page html
  res.end(str);
})

//delte all data in the database
app.get("/json/delete",function(req,res){
  //we'll need the response object and the data model
  utils.deleteAllData(res,salesMember);
})

//respond to request for /json
app.get("/json",function(req,res){
  //return every record in the database
  salesMember.find({}).exec(function (err, result) {
    var str = null;

    if (!err) {
    //stringify the database search result
    str = JSON.stringify(result, undefined, 2);

    //if a json callback was provided in the query string
    if(utils.isJsonCallback(req)){
      //wrap the json data with the named callbacck
      str = utils.wrapDataInCallback(req,str);
    };

    //deliver the json
    res.writeHead(200, {"Content-Type": "application/json"});
      res.end(str);
    } else {
      res.end("Error in first query. " + err)
    };
  });
})

//add user 
app.get("/addUser",function(req,res){
  var
  str = null,
  menu = "<br /><br /><b><a href=\"/\">Home</a>   <a href=\"/json\">View JSON Data</a></b>",
  url_parts = url.parse(req.url, true),
  query = url_parts.query,
  fname = query.fname,
  lname = query.lname,
  phone = query.phone,

  //add a new document to the collection
  newUser = new salesMember ({
    name: { first: fname, last: lname },
    phone: phone
  });

  //save the new document
  newUser.save(function (err) {
    if (err) console.log ('Error on save!')
  });

  //prepare the response
  res.writeHead(200, {'Content-Type': 'text/html'});

  str = ''
      + '<h1>New User Added!</h1><b>First Name -></b> ' + fname
      + '<br /><br /><b>Last Name -></b> ' + lname
      + '<br /><br /><b>Phone -></b> ' +  phone
      + '<br /><br /><b>This user\'s id is:</b> ' + newUser._id
      + menu;

  //send the response
  res.end(str);
});

//utility functions

//returns the name of the JSON callback, if there is one
utils.getJsonCallbackName = function(req){
  var url_parts = url.parse(req.url, true),
  query = url_parts.query;

  if(!url_parts.query || !url_parts.query.callback){return false};

  return url_parts.query.callback;
};

//takes the passed-in string and returns it
//wrapped in the callback name
utils.wrapDataInCallback = function(req,str){
  var
  start = utils.getJsonCallbackName(req) + '(',
  end = ')';

  return start + str + end;
};

//returns true if the query string contains a "callback" parameter
utils.isJsonCallback = function(req){
  var retVal = utils.getJsonCallbackName(req);

  if(retVal){return true};

  return false;
};

//deletes all data in the passed-in model
utils.deleteAllData = function(res,model){
  var successMessage = ''
  + '<h1 style="color:red">All data has been deleted from the database!</h1>'
  + '<b><a href="/">Home</a></b>';

  //delete all data
  model.remove({}, function(err) {
    if (err) {
      console.log ('There was an error deleting the old data.');
    } else  {
      console.log ('Successfully deleted the old data.');
    res.end(successMessage);
    } 
  });
};

//start the application
initApp();