Internet data in Mobile applications

8/7/2019 Internet data in Mobile applications

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Internet data in Mobile

applications

Sheik Dawood Jainullabudeen(sheikd at vishwak.com)

Vishwak Solutions Pvt Ltd



Types of Internet Data

Web Service

JSON

XML (RSS feed)



Web Service

Web services are typically application programminginterfaces (API) or web APIs that can be accessed

over Internet, and executed on a remote system

hosting the requested services



JSON

JSON, short for JavaScript Object Notation, is a

lightweight computer data interchange format. It is atext-based, human-readable format for representing

simple data structures and associative arrays (called

objects).



RSS

RSS (most commonly expanded as Really SimpleSyndication) is a family of web feed formats used to

publish frequently updated works²such as blog

entries, news headlines, audio, and video²in a

standardized format



UI Elements

Screen1: Lists the Category Titles

Screen2 : On Select of category ,2nd screen shows

the Description of the RSS story



Web API served from Web



Mobile RSS Reader

1. Choose the Data Source

2. Retrieve the RSS feed from webserver

3. Parse the RSS Feed

4. Store the RSS data as local objects(Array, List)5. Display the RSS feed in to Mobile UI

Components



Choose the Data Source(RSS feed )

Here we are connecting to RSS feedhttp://rss.cnn.com/rss/edition.rss



Retrieve the VVF feed fromwebserver

Before we do parsing and data manipulation of anRSS feed, the application should talk to internet and

retrieve the RSS feed

The Application connect to the site hosting RSS feed

through an Internet connection (GPRS or Wi-Fi) and

perform an HTTP GETHTTP GET operation to retrieve the RSS

data.

The data which comes back is not a file, it is a streamof XML data. The URL class is employed to fetch the

data.



Parse the RSS Feed(XML)

We can parse XML data with multiple mechanisms.

All of them involve the navigation of the data stream

and moving of one data element from another with

the opportunity to store the data.



Parse the RSS Feed(XML)

Two most popular approaches used for parsing the XMLnamely the DOM Parser, SAX Parser.

The DOM approach is well suited for complex XML documents

as it builds a node-oriented representation of the XML data in

memory. The SAX approach uses callbacks whenever new tags are

encountered, allowing the application to store only the data it

is interested in.



Store the RSS data as localobjects(Array, List)

The RSS feed extracted from the XML data streammust be put into a Mobile application (SDK)

understandable form.

RSSFeed and RSSItem, which store the parsed form

of the RSS XML data stream in memory.

Once the XML data stream is fully parsed, the

application interacts with these classes to render the

information.



Display the RSS feed in to AndroidUI Components

This RSS Application employs two Activity classes toprovide the user interface.

The primary screen lists the RSS feed title and

publication date followed by a list of the RSS items.

Once an item is selected through a tap, or enter in

the Android Emulator, the ShowDescription Activity

displays the full detail including the Title, Publication

Date, Description and Link elements of the RSS item.



Mobile Components Comparison

Sl. No Features RSS feed Address Retrieve the RSS

feed from

webserver

XML Parser -

(Parse the XML

data stream)

Store the RSS data Display the RSS feed in

to Mobile UI

Components

1 Android http://rss.cnn.com/rss/edition.rss Perform an HTTP

GET operation to

retrieve the RSS

data

SAX, DOM XML

Parser

Array, List TextViews, ListView

2 iPhone http://rss.cnn.com/rss/edition.rss Perform an HTTP

GET operation to

retrieve the RSS

data

NSXMLParser

,libxml2 SAX

Array, List Table View, UIView,

ImageView

3 Blackberry http://rss.cnn.com/rss/edition.rss Perform an HTTP

GET operation to

SAX, DOM XML

Parser

Array, Vector ListField

4 Windows Phone7 http://rss.cnn.com/rss/edition.rss Perform an HTTP

GET operation to

DOM Parser V ector Panoramic View Control

Comparisons of XML Parser, UI Elements



Challenges Faced Minimal dataexchange between mobile &internet

Internet Data in mobile connection (GPRS)environment is very slow.

The application cannot retrieve the data using mobile

internet(GPRS) fast as internet connectivity.

So the application should be talking to quick and

minimal data

Mobile Applications quickly get the data from the feed

and process it for display.



Challenges Faced Minimal dataexchange between mobile &internet

Mobile Application in Offline mode.

When user tries to connect Mobile application which

suppose to connect to internet should have interface

to show case the cached information available in the

device

Caching of data will help user to navigate minimum

level of information and when internet is available the

rest of the information will be shown.



XML VS JSON Data Bytes

Various API¶s and their size in XML, JSON format¶s

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Uncompressed XML vsCompressed JSON Data

Comparison between XML vs Compressed JSON format.

The JSON compressed data size is reduced compared to XML

format



PhoneGap

PhoneGap is an open source development tool for building fast, easy mobile apps with JavaScript

Mobile Development with different SDK , IDE

iPhone SDK(using Objective-C)

Android SDK (using Java)

Blackberry SDK (using JavaME)

Phonegap supports cross-platform framework for

device-neutral mobile development. Application is developed using Javascript libraries.



VVF on Iphone





VVF on Blackberry



Thank you

Documents

Internet data in Mobile applications