Applicaton Development using RESTful APIs

Application
Development using
RESTful APIs
Sourav Maji
4/7/14
Bachelor of Technology,
11/IT/35,
Information Technology,
National Institute of Technology,
Durgapur

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Acknowledgement
First I would like to thank Mr. Amit Bhagat, the co-founder of Surgerica, for giving me the
opportunity of doing an internship within their organization. I would sincerely like to offer my special
gratitude to Mr. Amarendra Kumar, the co-founder of Surgerica for constantly guiding me in the
right direction whenever I went a bit astray. He has been a constant source of encouragement
throughout the duration of my internship.
I also would like to thank all the employees who work at Surgerica. With their never ending patience
and openness they created a very enjoyable working environment for me.
Lastly, I want to thank all the students, with whom I had joined as an intern at Surgerica. We
experienced great things together and they have made the experience wonderful.
For me it was a unique experience to be in an actual working environment for the first time and to
work on a very interesting project. It also helped me understand the various work responsibilities
and the importance of meeting the project deadlines.

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Table of Contents
Sl. No. Topic Page No.
1. Acknowledgement 1
2. Significance of the project
 Why are APIs important for any business?
3
3. Introduction 4
4. Google Maps API
 My Project
 Front End
 Back End
5
6
8
5. WikiMedia API
 My Project
 Front End
 Back End
10
11
13
6. SMS Achariya API
 My Project
 Front End
 Back End
14
15
17
7. Conclusion 18
8. Reflection on the Internship 19

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Significance of the Project
Why are APIs important for any business?
“APIs make the modern Web what it is today.”
“APIs: building blocks for the future of digital marketing”
Application programming interfaces are helping marketing professionals cut through the digital
white noise. Understanding the world of Application Programming Interfaces (APIs) is one way for
agencies to stand out from the crowd whilst creating a unique experience for customers. Think of an
API as a plug - a simple and fast way to plug in and consume a service from a third-party provider.
Those services could be anything from content such as news, through to transactional services like
sending an email or SMS, making payments or placing a phone call. What's unique about APIs is now
one can consume these services through simple web interfaces that one’s software development
team can integrate in a matter of hours. Gone are the days of drawn out commercial negotiations,
the purchase and maintenance of third-party software and hardware, and time consuming,
expensive bespoke integrations. For these reasons APIs truly are a game changer.
Hurwitz & Associates
surveyed more than two
dozen leading edge
companies that are using
APIs to transform their
businesses. The results
were significant. The
research indicates that
companies that took
advantage of APIs
experienced benefits in
the following areas:
 Significant Improvement in Partner/Customer Reach. There was a greater than 70%
increase in connecting to important customers and partners to build more profitable
relationships.
 Increase in Web Traffic. There was 70% increase in web traffic and a 50% increase in web
service usage by customers once the Web API was implemented.
 Faster Time to On-board Partners. Early adopters discovered that there was a 30% decrease
in the amount of time required to on-board partners. At the same time there was a 30%
increase in the ability to bring new innovative ideas to market quickly.

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Introduction
What are APIs?
An application-programming interface (API) is a set of programming instructions and standards for
accessing a Web-based software application or Web tool. A software company releases its API to the
public so that other software developers can design products that are powered by its services.
An API is a software-to-software interface, not a user interface. With APIs, applications talk to each
other without any user knowledge or intervention. As a user, one only sees one interface, but
behind the scenes, many applications are working together using APIs. This type of integration is
called seamless, since the user never notices when software functions are handed from one
application to another.
An API resembles Software as a Service (SaaS), since software developers don't have to start from
scratch every time they write a program. Instead of building one core application that tries to do
everything -- e-mail, billing, tracking, etc. -- the same application can contract out certain
responsibilities to remote software that does it better.
What are RESTful APIs?
The evolution of network protocols has led to the acceptance of a stack of agreed upon standards,
each addressing computer communication in a specific way. At the top of this stack are the
Application and Presentation layers, where business logic and the data resulting from it are
exchanged.
REST (REpresentational State Transfer) is a simple stateless architecture that generally runs over
HTTP. REST generally involves reading a designated Web page that contains an XML file. The XML file
describes and includes the desired content.
Some of the other technologies that are used are SOAP (Simple Object Access Protocol) approach,
which requires writing or using a provided server program (to serve data) and a client program (to
request data), JMS (which is specific to Java applications) and XML-RPC (which has many of the same
problems as SOAP without any of the benefits of standardization).
REST allows for a minimum amount of data to be passed using the same well-established
mechanisms that define the web without a lot of the encumbrances introduced by fatter protocols.
This allows programmers to more rapidly build programs that access and act upon data exposed via
APIs, even in environments with unreliable network speeds and limited computing power.
REST works almost exactly like a website in a browser. A resource is exposed to a program via a URL.
The program can access that URL and receive data about the resource, not unlike when you type in a
URL to your browser and get a web page back. Well-designed RESTful APIs include additional links
the program can follow to request related information - similar to how one would click on a link to
visit a new page - or to submit data to update the given resource - similar to how one would fill out a
web form to create a new account for a web site.

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Google Maps API
The Maps Engine API is a RESTful API. All requests to the API are
HTTP requests, so that any programming language with an HTTP
library can be used to query or modify data in the API. Resources are
represented as JavaScript Object Notation (JSON). JSON is a widely-
supported standard, with parsers available in most programming
languages.
Google maps API provides a wide assortment of services and contains more than 150 features, some
of which are:
o Drawing on the Map
o Markers
o Info Windows
o Shapes
o Symbols
o Ground Overlays
o Custom Overlays
o Layers
o Map Types
o Services
o Libraries

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MY PROJECT
I have created an Application where a user inputs his location, presses the submit button and is
taken to another page containing a list of hospitals, and their distances from the user. He is also
provided with a link which will display to him his travel directions on a map to any of the hospitals of
his choice.
Front End:
1. A user will find a Submit Panel asking the user to input his location. While typing his address, he
will also find a list of possible suggestions based on the letters he has typed. All suggested addresses
are limited to India. On completing the address he just has to click on the GET DISTANCE button
(refer to the picture below).
2. After clicking on the GET DISTANCE button, the user will be taken to a different page, displaying a
list of hospitals and their corresponding driving distances from them. The list also features a
NAVIGATE option to get the Driving directions to the hospital from the users location (refer to the
picture below).

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3. A map showing the destination Hospitals and the user’s origin is also displayed alongside the table
4. When the user clicks on the NAVIGATE link in the table, a map opens up in a popup window which
displays the Driving directions to the hospital of his choice (refer to the picture below).

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Back End:
1. In the initial Submit Panel, I have used the Google Places library to autocomplete the address field.
Below is a code snippet:
<script
src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false&libraries=places">
</script>
<script type="text/javascript">
defaultBounds = new google.maps.LatLngBounds(
new google.maps.LatLng(8.06, 68.01),
new google.maps.LatLng(37.01, 97.25));
function autocompletef() {
var options = {
bounds: defaultBounds,
componentRestrictions: {country: 'in'}
};
Autocomplete = new
google.maps.places.Autocomplete((document.getElementById('origin')), options);
}
</script>
2. For the Distances table, I have used AJAX calls to fetch the latitudes and longitudes from the
database and then used Google’s Distance Matrix service to calculate the driving distances from the
user inputted location. Below is a code snippet:
<script type="text/javascript">
$(document).ready(function() {
$(':submit').on('click', function() {
$.ajax({
url: 'query.php',
data: 'button=' + $(this).val(),
dataType: 'json',
success: function(data) {
var destination = new Array();
var $_GET = [];
window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi,
function(a, name, value) {
$_GET[name] = value;
});
var origin1 = ($_GET['origin']);
for (var i in data.id) {

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destination[i] = new google.maps.LatLng(data.lat[i], data.lon[i]);
}
var service = new google.maps.DistanceMatrixService();
service.getDistanceMatrix(
{
origins: [origin1],
destinations: [destination[0], destination[1], destination[2],
destination[3], destination[4], destination[5], destination[6], destination[7]],
travelMode: google.maps.TravelMode.DRIVING,
unitSystem: google.maps.UnitSystem.METRIC,
avoidHighways: false,
avoidTolls: false
}, callback);
}
});
});
return false;
});
</script>
3. For displaying the Driving directions on the popup map, I have used Google’s Direction Service
API. Below is a code snippet:
var request = {
origin: start,
destination: end,
travelMode: google.maps.TravelMode.DRIVING
};
directionsService.route(request, function(response, status) {
if (status == google.maps.DirectionsStatus.OK) {
directionsDisplay.setDirections(response);
distanceInput.value = response.routes[0].legs[0].distance.value / 1000;
durationInput.value = response.routes[0].legs[0].duration.value / 3600;
origin.value = decodeURIComponent(org);
hosp.value = decodeURIComponent(hospital);
}
});

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WikiMedia API
The MediaWiki web service API (or WebAPI) provides convenient
access to wiki features, data and meta-data.
It provides direct, high-level access to the data contained in
MediaWiki databases.
A simple example:
This URL tells English Wikipedia's web service API to send us the content of the main page:
http://en.wikipedia.org/w/api.php?format=json&action=query&titles=Main%20Pa
ge&prop=revisions&rvprop=content
Using any programming language to make an HTTP GET request for that URL (or just visiting that link
in a browser) one will get a JSON document which includes the current wiki markup for the page
titled "Main Page". Changing format to jsonfm will return a "pretty-printed" HTML result good for
debugging.

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MY PROJECT
I have used the Wikipedia API to fetch wiki data relating to different illnesses, health conditions and
surgeries into a webpage of our own.
Front End:
1. A user will find a table listing a number of surgeries and illnesses and a corresponding “Go” link
2. Clicking on the link will take the user to a page displaying a short description of the illness with a
“View More” link at the end (refer to the picture below).

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3. Clicking on “View More” will take the user to a more detailed page about the same illness or
surgical procedure (refer to the picture below).

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Back End:
I have created a database containing a list of health conditions and surgery procedures, along with
their corresponding pages in Wikipedia. The list of surgeries is displayed to the user in an HTML
table. The link passes a GET variable containing the selected Wikipedia page title to a WikiDemo
page on our server. The page processes the GET variable and invokes the Wikipedia API by making
an API call. A code snippet is given below:
<script>
var $_GET = [];
window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi, function(a, name, value)
{
$_GET[name] = value;
});
var page = ($_GET['pages']);
$.getJSON('http://en.wikipedia.org/w/api.php?format=json&action=parse&page='
+ page + '&section=0&callback=?&prop=text', function(json) {
$('#wikiInfo').html(json.parse.text['*']);
$("#wikiInfo").find("a:not(.references a)").attr("href", function() {
return "http://www.wikipedia.org" + $(this).attr("href");
});
$("#wikiInfo").find("a").attr("target", "_blank");
});
</script>
The $.getJSON method makes an HTML GET request to the Wikipedia API and receives the required
data in JSON format. It then parses the data using json.parse.text[‘*’] function and displays the
content in the div element ‘wikiInfo’.

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SMS Achariya API
API codes can be easily integrated to any web or
software application. The robust & stable HTTP API
is Compatible with all Programming Languages & Operating Systems. The XML API is designed to
send huge messages through a single push.
The API works on GET and POST METHOD, and the url to be used is http://yourdomain/api/sms.php
For every successful execution of the API call, the system generates a 'Response' which one can save
for tracking the operation. For multiple requests, the system response will consist of unique numeric
ids or other forms of responses, separated by comma.
Four different types of messages can be sent using the SMS Achariya API: Normal route, Priority
route, Marketing route, Transactional route.

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MY PROJECT
In my Project Application, I have made an SMS Gateway for Transactional SMSs which support DND
templates. Moreover the content of the messages is dynamic, i.e. although the messages follow a
basic template the information carried by them has to be dynamically fed to them at the time of
sending.
Front End:
1. A user will be presented a list of customers and asked to select one to send an SMS. There are also
options on this page to add new customer details, view previous message logs, and a search field to
search for any customer using his mobile number.
2. After clicking on the Send SMS button the user will be taken to another page, asking him to select
one of the many previously approved DND templates.

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3. After selecting the desired template, the user now needs to fill in the dynamic values.
4. The complete message with the typed in values is displayed to the user. If he is not satisfied he
can go back to the previous page to fill the values again, or if he is happy, he can proceed to send the
SMS.
5. This final page reports whether a message has been sent or not. If the SMS was not sent, the
reason for the error is displayed otherwise the message is stored in the database along with the
message id and time for future referrals.

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Back End:
The whole application is built using PHP. Unauthorised use of the SMS Gateway is restricted by the
use of Sessions. The different values are passed from one page to another using HTTP GET and POST
methods. The final message is sent by hitting the SMS Achariya API with a url containing the
message and other various parameters. This is done using cURL function in PHP. Here is the code
snippet:
$message = urlencode($message);
$parameters =
"uid=$uid&pin=$pin&sender=$sender&route=$route&tempid=2&mobile=$mobile&messa
ge=$message";
$url = "http://$domain/api/sms.php";
$ch = curl_init($url);
if ($method == "POST") {
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $parameters);
} else {
$get_url = $url . "?" . $parameters;
curl_setopt($ch, CURLOPT_POST, 0);
curl_setopt($ch, CURLOPT_URL, $get_url);
}
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$return_val = curl_exec($ch);

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Conclusion
What is the future of APIs?
APIs are about to enter a new phase, one where developers can easily program using multiple APIs
at once, and non-developers can easily introduce API automation into both their business and
personal worlds. A time where APIs are seen as a valuable resource anyone can quickly put use, not
just as a technical interface only high-end developers understand.
Web APIs have matured out of its earlier service oriented architecture (SOA) roots, often shedding a
rigid SOAP approach to a more flexible RESTful implementation, increased efficiency by opting for
more lightweight JSON over bloated XML, and becoming more accessible with API explorers and
interactive documentation.
Now with over 6,000 public APIs available, there is a need to get more efficient about how we work
with APIs, and evolve to where we can truly program the web. But to get there, we have to add a
new platform layer that can help standardize the authentication, interfaces and resource types
available--simplifying how not just developers, but average users can take advantage of APIs.
One approach is targeting developers with new languages, or extensions of existing languages that
can be used to program against one or many APIs. The second approach is targeting a wider
audience with automation platforms that create API driven tasks. Both approaches provide a much
needed platform to help make APIs more accessible, where one is still targeting the developer
community and the other will allow anyone to take advantage of APIs through special automation
tools and connectors.
The beauty of an API is that pretty much any kind of implementation is possible. The API is the
ingredient, and the recipe is only constrained by the imagination of the developer.

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Reflection on the Internship
Regarding my learning goals I shortly discuss my experiences; if I have achieved my goal, whether I
experienced difficulties and what I think I have to improve.
Learning goals
The functioning and working conditions of an organization: At the beginning, I did not have any
experience of working in any organisation, but with time I learned the importance of meeting
project deadlines and working under an authority.
Enhancing communication skills: My stay has contributed to my communication skills, and I would
like to sharpen it even more in the future. To contribute more to projects and to progress faster, I
want to learn to make a more confident impression and to express my ideas and opinions more
certain.
The use of skills and knowledge gained in college: A lot of the concepts I had learnt at college were
mainly theoretical and lacked much practical application. The subject of Internet and Web
Technology which was taught in the previous semester was really helpful in building the
applications. I could finally put my academic knowledge to actual use.
Skills and knowledge that might be improved to work in a professional environment: During the
internship, I have realised that a lot of technical knowhow is important and one should be
completely updated about the technological advancements in order to work in a professional
environment. I also figured out that prior planning is vital for projects to be completed within a
stipulated amount of time.
Learning new Skills: I was introduced to the wonderful world of APIs and loved programming with
them. I learned that APIs are indeed very important in today’s scenario where Applications can
interact with one another without human intervention. A lot of large web services have their own
APIs and it has grown a curiosity within me to explore new ones.

Applicaton Development using RESTful APIs

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