Lipstick on a Pig

Dynamically re-skinning a
legacy .NET portal with python

Matt Hamilton
matth@netsight.co.uk

Introduction

Dynamically re-skinning a .NET portal site

Can't name the client

Portal for teachers in the UK

Aggregating content across legacy portal, Plone and Moodle

Who Am I

Technical Director of NetsightWeb development firm in UK

10 years experience with Zope/Plone

More of an integrator than core developerI get involved in all those sticky projects of merging Plone in with other systems in an enterprise

Where Were We?

Existing Portal (1.0)

Five years old by November 2009

User registrations: 46,681

Course enrolments: 33,664

Resource Bank views: 247,911

Existing Portal (1.0)

Problems with Current Portal

Look-and-feelNot very compelling

UsabilityChallenging in places

A poor content management systemCan't really edit general content, so use a separate FTP server and Dreamweaver

Vendor lock-inEven small changes, very expensive

The Future - Portal 2.0

Usability, Design and Content Review April 2008

Strategic Review August 2008

Feasibility Studies Jan 2009

Pilot Demonstrator (Portal V1.5) March 2009

Design Review

Architecture Review

Portal 1.0 - Monolithic, tightly coupled, poor separation of skin

Architecture Review

Portal 2.0 - Extensible, loosely coupled, good separation of skin

How Do We Get There?

Remember: We Can't Touch the Existing System!

The Cunning Plan

Skin 1.0

Portal 1.0ExistingPortal

Module of functionality e.g. portfolioBrowser

Total Skin Graft!

Portal 1.5New skin via xpath and xslttransformation.

Web server needs to handle SSL.

Together they give us nice URLs.Skin 1.0

web servertransformation proxySkin 2.0

Browser

Deliverance

Several Different Projectsxdv

Deliverance 0.3

Nate just talked about Deliverence, so I won't go on about it

WSGI

WSGI allows you to write small modules chained together in a 'pipeline'

Many small filters combined together as you need

Lots of existing components out there

Very easy to write new ones

WSGI Power - The Pipeline

[pipeline:portal]pipeline = theme.portal ploneinterceptor xslt linkrewrite htmlcleaner source.portal

[filter:theme.portal]use = egg:dv.xdvserver#xdvtheme_uri = file://%(here)s/theme/theme.htmlrules = %(here)s/rules/content.xml

[filter:ploneinterceptor]use = egg:ns.ploneinterceptor#ploneinterceptor

[filter:xslt]use = egg:dv.xdvserver#xsltxslt_file = %(here)s/rules/transform.xsl

[filter:linkrewrite]use = egg:ns.linkrewrite#linkrewrite

[filter:htmlcleaner]use = egg:ns.htmlcleaner#htmlcleaner

[app:source.portal]use = egg:Paste#proxyaddress = http://www.theexistingsite.org.uk/

Link Rewriting

Old URL:http://www.theclient.org.uk/WebPortal.aspx?page=1&module=DB920A53-01EA-4886-8878-F2CDF5FA8CFD&mode=101&IsNonNewsDB920A53_01EA_4886_8878_F2CDF5FA8CFD=True&newsIdDB920A53_01EA_4886_8878_F2CDF5FA8CFD=11208#10

205 characters!

New URL:http://www.theclient.org.uk/news/11208#10

41 characters!

HTML Cleanup

LXML rules!from lxml.html.clean import Cleaner
cleaner = Cleaner(...)
# Pretty print the HTML
dom = document_fromstring(body)
body = etree.tostring(dom, pretty_print=True)
# Clean the HTML
body = cleaner.clean_html(body)

Result

Old70kb of HTML

120 Validation errors, 61 warnings

New40Kb of HTML

27 Errors, 1 warning (mainly xhtml/html conflicts)

No significant performance impact

Putting all together

Composite:mainpipeline:portalpipeline:plonepipeline:moodletheme.contentnavmergerplonecontentsource.plonetheme.contentxsltlinkrewritehtmlcleanertheme.contentnavmergermoodlecontentsource.moodlesource.portal

End Result

New Style

Portal content

Complications

NavigationOne page, two content sources, how is the navigation built?

SearchSearch needs to go across multiple systems

Will soon be looking at Solr, Xapian, Google Mini

.NET viewstate postbackMassive hidden state variable, form wraps entire site!

Questions?

matth@netsight.co.uk

13th May 2009

European Plone Symposium 2009