component-based development of adaptive mobile web applications

Heiko Desruelle

Component-based development ofadaptive mobile web applications

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Enormous fragmentation of mobile platforms and device characteristics ...

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Native mobile applications

Application developers are forced to target multiple mobile platforms

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Platform Language Market share 2009

iPhoneOS Objective C 18%

Android Java (Dalvik JVM) 4%

Windows Mobile .NET / C++ / Java 8%

Symbian C++ 46%

Palm OS C, C++ 1%

Blackberry Java (with RIM API) 21%

Vakgroep Informatietechnologie – Breedbandcommunicatienetwerken (IBCN)6


Native App Stores Web Apps

Openness Restricted Completely open

Entry Cost $0 - $200 None

Developer Revenue 30% - 80% 100%

Approval Few days - weeks Instantaneous

Current distribution models for native applications also have their drawbacks

Vakgroep Informatietechnologie – Breedbandcommunicatienetwerken (IBCN)7


Application stores are not always goldmines Restrictive store policies, low revenue rates

Ranking-based system

Dapple app: $32,000 invested vs. $535 revenue

Native App Stores Web Apps

Openness Restricted Completely open

Entry Cost $0 - $200 None

Developer Revenue 30% - 80% 100%

Approval Few days - weeks Instantaneous

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MOBILE WEB APPLICATIONS

Powerful devices

Fast network connections

Affordable data plans

The Web as an alternative mobile platform

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Native vs. Web applications

Application development using standardized Web technology such as HTML, CSS and JavaScript.

However, the available device APIs for Web-based development are limited to geolocation, local storage

and screen orientation information.

W3C and BONDI are currently addressing this issue. Meanwhile, hybrid development solutions

(e.g. PhoneGap) can be used for richer device interaction.

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Native vs. Web applications

Web application development

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iPhone / iPod Other WebKit LCD

Web application development

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“Create once, run everywhere”

The ultimate goal is to provide a single application that is able to serve a diversity of

mobile devices.

To face fragmentation issues,

Web applications need a high degree of adaptivity.

Component-based development

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Component-based approach

The developer only defines what type of building blocks his application is made of.

The application server takes care of the specific rendering, based on the client devices’ capabilities.


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... How to implement such an adaptive Web application framework?


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Challenges:

Automatic evaluation and selection of optimal component versions. Easy framework extensibility with new component versions, etc.

Component selection

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IF (iPhone, iPod)

jQTouch component version

ELSE IF (jQuery support)

jQuery component version

ELSE IF ...

Nai

ve a

ppro

ach!

Component selection

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IF (iPhone, iPod)

jQTouch component version

ELSE IF (jQuery support)

jQuery component version

ELSE IF ...

Nai

ve a

ppro

ach!

Strong dependencies between component versions Adding new component versions rapidly becomes

unmanageable

High risk for version conflicts

Error prone, requires the modification of other developers’ code

Component evaluation

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Actual device Matches this version

Touch NO

Stylus YES

Joystick NO

Clickwheel NO

e.g. selection rule: pointing method = stylus

Nai

ve a

ppro

ach!

Boolean similarity evaluation

Component evaluation

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Actual device Matches this version

Touch NO

Stylus YES

Joystick NO

Clickwheel NO

e.g. selection rule: pointing method = stylus

Nai

ve a

ppro

ach!

Boolean similarity evaluation

Infeasible due to device diversity Requires entire spectrum of device capabilities to be covered

Impossible to provide optimal component version for each context

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TOWARDS ADAPTIVE WEB APPS

Proposed approach: Algorithm

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Proposed approach: Algorithm

The proposed framework implements the Logic Scoring of Preferences (LSP) method, with

optimizations for mobile usage.

Fuzzy logic evaluation

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Not simply yes-or-no decisions

Include degrees of “maybe-ness”

Fuzzy similarity evaluation

Fuzzy logic evaluation enables the objective selection of less-than-perfect component versions, in case no optimal candidate is

available.

Fuzzy logic evaluation

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Not simply yes-or-no decisions

Include degrees of “maybe-ness”

Fuzzy similarity evaluation

Logic aggregation

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Multiple device characteristics can be used to evaluate the candidate components.

Elementary degrees of similarity will need to be aggregated into an overall objective score.

LSP provides a number of logic aggregators.

Logic aggregation

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Aggregation of individual degrees of similarity Pointing method, CSS capabilities, ...

Different types of aggregators Mandatory vs. desired, incremental scoring vs. penalties

Results in an objective and overall score for each selection candidate

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Proposed approach: Architecture

Component generator

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Optimal candidate selection

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Application request handling

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Application request handling

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QUESTIONS?

E-mail: [email protected]

Twitter: @heiiko

component-based development of adaptive mobile web applications

Technology

decisions

fuzzy logic

jqtouch component

jquery component

version touch

jquery support

based development

naive approach