1. Desperately Seeking… a lightweight Perl web framework
Peter Edwards
Desperately seeking... a lightweight Perl web framework
06/12/2018

2. Introduction Subject Peter Edwards ~ background
Explain about the processes and decision making involved in assessing, selecting and using a Perl web framework
Desperately seeking... a lightweight Perl web framework
06/12/2018

3. Aims Learn what frameworks are out there Technical considerations
Business tools for decision-making
Audience: What is your background and interest?
Desperately seeking... a lightweight Perl web framework
06/12/2018

4. Topics Define the problem Example requirements
Attributes of frameworks
Business decision making tools
Architecture
Application components
Perl application frameworks
Roll your own
Summary
Desperately seeking... a lightweight Perl web framework
06/12/2018

5. Define the Problem Why do you need a web app?
What functionality / how complex? no. screens, other features, e.g. search engine, integration to other apps/components/company infrastructure, server platform
Business setting Project length, size; Developer expertise, skill sets; Integration to network, database type, existing frameworks e.g. ADS authentication; Capacity plan - no. of users and required performance
Desperately seeking... a lightweight Perl web framework
06/12/2018

6. Example http://merlinfootball.com
Components Flash front end, sending XML transactions to Perl back end Perl XHTML admin system
Elements Huge volume of users and transactions Streaming video Picture upload and approval to gallery FAQ submission, approval and editing into FAQ list
Desperately seeking... a lightweight Perl web framework
06/12/2018

7. Attributes of Frameworks
Size -> complexity
Learning curve
Vertical vs. horizontal
Functionality, flexibility
Monotheistic/"One True Way" vs. agnostic
Increased power, reduced performance
Cost of testing new code = 50% of time
By extension DRY KISS
Desperately seeking... a lightweight Perl web framework
06/12/2018

8. Business Decision Making Tools
The point of business Increased shareholder value - cash
William of Occam, 14th century logician and Franciscan friar entia non sunt multiplicanda praeter necessitatem entities should not be multiplied beyond necessity "All things being equal, the simplest solution tends to be the best one.“ It often happens that the best explanation is much more complicated than the simplest possible explanation because it requires fewer assumptions.
Pareto Principle, by Joseph M. Juran named after Vilfredo Pareto, Italian economist "for many phenomena, 80% of the consequences stem from 20% of the causes“ -- en.wikipedia.org
Cost Benefit Analysis Estimate days for development Estimate hidden costs and benefits e.g. of more stable framework Cost comparison -> decision Perfection vs. pragmatism
Desperately seeking... a lightweight Perl web framework
06/12/2018

9. Architecture I
Web Protocol HTTP request/response URI, REST, URL parameters Web 2.0, AJAX
Web Server Apache, IIS, lighttpd CGI/mod_perl, FastCGI
Controller Processing Apache registry style stacked phase handlers MVC Model View Controller Single entry point vs. separate CGI
Desperately seeking... a lightweight Perl web framework
06/12/2018

10. Architecture II
Session CGI::Session Apache::Session Catalyst::Plugin::Session -> Cache::FastMMap
Security Authentication Group permission roles HTML field and SQL field encoding
Database layer Direct DBI Simple Class::DBI ORM Object Relational Mapper DBIx::Class Rose::DB Performance considerations - DBI x faster Data object attributes - data dictionary - screen dictionary
Desperately seeking... a lightweight Perl web framework
06/12/2018

11. Architecture III
Templates Template::Toolkit (TT2) variable merge, not too complex, encourages using Perl in app modules HTML::Mason – inline code Personal preference; understandable by Web designers XHTML, accessibility, internationalisation Locale::Maketext Form handling, CRUD from db object, validation Data::FormValidator Rich components
Testing module unit test, business data object tests, Javascript/browser compatability checks Test::More Test::WWW::Mechanize Test::WWW::Selenium
Desperately seeking... a lightweight Perl web framework
06/12/2018

12. Application Components
Pre-built components save time in short term on testing; may cost more long term; integration costs PHP::Session
Language Repository Template Component Perl CPAN TT2 Bricolage PHP PEAR Smarty CMSMS Python Built-in Clearsilver Trac
Desperately seeking... a lightweight Perl web framework
06/12/2018

13. Perl Application Frameworks
CGI::Application + CGI::Session lightweight, easy to use, reliable, full control, open
Watch out for CGI::Builder, based on CGI::App but used to have Makefile.PL that downloaded and eval'd code, also bizarre "Perlish" coding style ; use 5.006_ ; use Carp ; $Carp::Internal{+__PACKAGE__} ; $Carp::Internal{__PACKAGE__.'::_'}++ ; use IO::Util
CGI::Framework fixed - glue between HTML::Template, CGI::Session, CGI, Locale::Maketext last release 11-Oct-2005
Jifty one true way: database mapper, template, web services, AJAX toolkit, handlers for FastCGI continuations, form-based dispatch "Jifty is the only web application framework that comes with a pony“
Gantry + Bigtop Apache/mod_perl, MVC Bigtop - web application data language processor, app generator
OpenInteract + SPOPS Complex, slow, powerful, CMS-oriented permissions last release 18-Mar-2005
Catalyst agnostic, MVC, complex, magic, powerful, slow (third time in NEXT/C3 OO extension), well tested Works well with DBIx::Class and TT2; can also use Class:DBI, HTML::Mason Many plugins for auth, XML etc.
Maypole (ancestor of Catalyst) similar approach Class::DBI, TT2
Desperately seeking... a lightweight Perl web framework
06/12/2018

14. Roll Your Own
"Not invented here" syndrome, AKA submitting a module to CPAN with "Lite" or "Plus" in the name.
Can base on CGI::Application + CGI::Session
Or write one yourself. Easier than you'd think. Here's one written in a week, not pretty but delivered a project delivered fast and on time:
Desperately seeking... a lightweight Perl web framework
06/12/2018

15. Summary Processes and decision making requirements business context
CBA decision basis
technical considerations, architecture, constraints and features
application components
Perl application frameworks
Desperately seeking... a lightweight Perl web framework
06/12/2018

16. Where to Get More Information
CPAN
Books
Any Questions
These slides are at
Desperately seeking... a lightweight Perl web framework
06/12/2018