What is Node JS and why?
Node JS is a java script based web development platform, where we
can develop and host Web applications and Web Services.
Let’s assume a scenario where we
need to access SharePoint resources (list/library data) on mobile app or some
other web application. The first thing comes to our mind is a web service. Now we have two options to implement a web
service:
1. WCF RESTful
Service in C# and
2. NODE JS Web
API.
The reasons to
choose Node JS web service over WCF service are:
1. Open source
2. Lightning
Fast Speed
3. JavaScript
based
4. Comparatively
faster than WCF
5. Easy to Unit
Test
Prerequisites
- Node JS – Download and Install latest version of Node JS from here.
- Custom packages from GitHub – Download and install node packages as and when required. The cmdlets to install packages are explained in “Install Node packages” section.
- Visual studio/any other IDE
Supports only Basic or NTLM Authentication of SharePoint
To communicate with SharePoint, we
are going to use a node package HTTPNTLM.
It supports only NTLM authentication mode of SharePoint. If your SharePoint
site supports claims based authentication, we may achieve it using a node
package called request. ButI amnot
going to explain it here.
Install Node Packages
Node packages can be installed
using node console which will be available after installation of Node JS. Below
are the packages that we need to install.
httpntlm
httpntlm package is used to communicate
with SharePoint REST APIs. We just need to pass the credentials
$ npm
install httpntlm --save
express
Express is a Node JS’s web
application framework that provides a robust set of features for mobile and web
applications
$ npm
install express –save
cors
cors package allows a Web API to
accept cross domain requests.
$ npm
install cors –save
xml2js
Used to convert xml data into JSON
format
$ npm
install xml2js –save
deasync
Used to make synchronous calls to
java script functions
$ npm
install deasync –save
What is Express App
Express is a most popular web
application framework in Node JS just like MVC in .NET. If you are using Visual Studio, download a
project template for Node JS form here. Create a
new project of type ‘Basic Node.Js Express 4 Application’.
Replace the code in app.js with below code snippet.
If you are not using Visual
Studio, create a JS file namedapp.js
and put the below code snippet:
“use
strict”
var express =require('express');
var app =express();
varroutes =require('./Routes')(app); //to be added in
next step
app.listen(4444); // app.listen(<Port no>)
module.exports = app;
Routes
Routes are the application
endpoints which redirects to specific web service depending upon the Request
type (GET/POST) and URI. Create a folder
named Routes and add a file named index.js.
Put below code:
“use strict”
module.exports= function(app) {
varservices= require ('../Services');
varcors = require ('cors');
app.use(cors());
//Services Routes
app.get('/_api/getAllEmployees',cors(),Services.getAllItems); // app.post ('/_api/addEmployee',cors(),Services.addItem);
}
Observe the above code snippet and
find the routes.
Routes: '/_api/getAllEmployees' and /_api/addEmployee
Services
Now it’s time to access SharePoint
resources using REST API. Let’s expand the above codeadd definition for Services.getAllItems. Add a new folder named
Services and add a JS file named index.js
and put below code in it:
“use strict”
var httpntlm = require('httpntlm');
var parseString = require('xml2js').parseString;
var deasync = require('deasync');
var siteURL = "http://<SiteCollectionName>", domainName = "<domain name>";
//1.Get All Employee Service
exports.getAllItems = function (req, res) {
var httpResponse = { "statusCode": 500, result: undefined };
var url = siteURL + "/_api/web/lists/getByTitle('<ListName>')/items";
var headers = { "Accept": "application/json;odata=verbose",
"content-type": "application/json;odata=verbose;"
};
httpntlm.get({
url: url,
contentType: 'application/json;odata=verbose',
username: '<MyUsername>',
password: '<MyPassword>',
domain: '<DomainName>',
workstation: '',
headers:headers},
function success(error, response) {
httpResponse.result = JSON.parse(response.body);
res.send(httpResponse);
})//End of get
};//End of getAllItems
I am not writing the Code for post
method here, that will allow you to get some hands-on experience on node JS. :)
Run The Web API
You can run the web api using a
cmdlet node as
$ node
app.js
To test if it’s functioning or
not, put the URL in browser and check the response:
http://<ServerName>:4444/_api/getAllEmployees
Summary
Node JS is a web hosting platform
for Web sites and Web Services. Follow the steps as mentioned in this post and
access the required SharePoint resources.
Any questions, comments and
suggestions are most welcome! Have a great day ahead!
