Online Retail with Perl

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Online Retail with Perl
Jon Allen
http//perl.jonallen.info - jj_at_jonallen.info
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Background

• www.pennysarcade.co.uk launched November 08
• Lots of CPAN used
• 169 CPAN distributions (including dependencies)
• Three key modules power the site
• Catalyst (web framework)
• Handel (basket order processing)
• OpenThought (AJAX user interface)
• Proud to use Perl! ?

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Catalyst intro (1)

• Very different to traditional CGI programming
• No scripts
• Website is a complete application
• URL dispatch controls which methods are invoked
• http//mysite.com/view/image/1234/square
• MySiteViewimage(1234,square)
• Very flexible
• Method behaviour defined using attributes
• Multiple methods can be called in a single request

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Catalyst intro (2)

• Layered architecture
• Model (database / business logic)
• Controller (application logic)
• View (output)
• Example customer receipts
• Model data logic, delivery calculation, etc
• Returns an order object
• HTML View produces web page
• PDF View produces shipping receipt

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Why did we choose Catalyst?

• Proven, stable technology
• Fantastic documentation
• Plugins
• Session handling, access control, etc
• Support community and commercial
• Quick to develop in
• Easy to install, built-in development server
• Simple deployment
• FastCGI application server

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e-Commerce basics

• SKU Stock Keeping Unit
• Represents an individual item sold, i.e. a
  product in 2 colours and 3 sizes 6 SKUs
• Shopping basket temporary storage
• User browses site, adds items to basket
• Orders the good part!
• Basket converted to order revenue

SKUs
Baskets
Orders
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e-Commerce basics

• SKU Stock Keeping Unit
• Represents an individual item sold, i.e. a
  product in 2 colours and 3 sizes 6 SKUs
• Shopping basket temporary storage
• User browses site, adds items to basket
• Orders the good part!
• Basket converted to order revenue

SKUs
Baskets
Handel
Orders
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Handel

• Not a complete e-Commerce package
• Toolkit for building e-Commerce applications
• This is a good thing
• Manages baskets and orders
• Object-oriented
• Add / Remove / Update / Inspect methods
• Catalyst model
• Easy to subclass
• e.g. add custom delivery calculations / data
  fields

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Taking payments

• Merchant account
• Lets you accept credit / debit cards
• Different types Internet, MOTO, Retail
• Available from most banks or American Express
• Small cost per transaction
• Payment processing
• XML over HTTPS
• Complex security requirements PCI-DSS
• Often easier to outsource this bit!

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Payment process
Customer enters credit card details
Order amount in HTML form
https//yoursite/checkout
POST
https//payment/processor
Basket converted to order (Handel)
Acquiring bank (3D Secure)
https//yoursite/success
https//payment/processor
POST
https//yoursite/fail
Success or failure page displayed
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User Interface

• Crucial to the shopping experience
• OpenThought AJAX transport library
• See http//perl.jonallen.info/talks/lightweightaja
  x
• Developed a Catalyst view for OpenThought
• Not on CPAN yet, but will be
• Live demo
• Weather permitting! ?

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Other useful things (1)

• PDFReuse
• Modifies existing PDF files
• Great for printing receipts
• Design template (e.g. in Microsoft Word)
• Save as PDF
• Create a Catalyst view using PDFReuse to insert
  customer details from Handel model
• Much less work than coding the full PDF document
  by hand

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Other useful things (2)

• Read Léons book

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Other useful things (2)

• Read Léons book
• Buy Léons book!
• www.tickmyboxes.com
• 100-point checklist of best practice
• Lots of useful tips

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Conclusion

• Site was delivered under budget and ahead of
  schedule
• Could not have achieved this without Perl and
  CPAN
• Development and Operations are the easy bits
• Marketing and Promotion is where it gets
  difficult!
• Treat your home, treat someone special, treat
  yourself at www.pennysarcade.co.uk

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Fin!
Thank you for listening!
Any questions? http//perl.jonallen.info/talks