Proof of concept - enabling SSI on Plone 3 portlets

Snowsprint 2008 is over for this year and many thanks to Lovely Systems and all participants.

Since Lovely Systems has deployed some fast sites I was eager to see if I could reuse some of it with Plone. One of the products was lovely.remoteinclude which enables viewlets to be accessed through own unique urls and therefore cached separately. With nginx you can then use SSI (server side include) to assemble the page instead of doing it all in Plone. The lovely.remoteinclude hooks up adapters for all IIncludableViews if they send the event zope.contentprovider.interfaces.IBeforeUpdateEvent. The adapter then checks if the view is called from within a page or directly. If it is called within a page the render method is changed so it renders the url to the view, and when called directly, no changes are made.

My task was to try to make Plone portlets accessible through urls. This was little bit harder then just marking the PortletManager and PortletRender with IIncludableView since they where not normal viewlets or viewlet mangers and there was no acquisition in portlets. Anyway after some pair programming with Tom Gross we managed to create a package valentine.remoteinclude (we didn't dare to name it plone.remoteinclude). This package is a proof of concept that lovely.remoteinclude can be used on Zope2 and Plone. It will provide urls for portlets that are available on the plone root. While we were learning the plone portlet machinery we found the namespace ++contextportlets++ which we reused to generate urls for our portlets. We also added a namespace for portlets since the ++viewlet++ didn't work for plone portlets. An url to a default calendar portlet will look like:

<!--#include virtual="/++contextportlets++plone.rightcolumn/++portlet++calendar" -->

Together with Whit Morriss and help from Tim Terlegård(who made lovely.remoteinclude work with Grok viewlets) we set up a buildout that will build a nginx and a varnish prepared for SSI and lovely.remoteinclude. The templates were made from a configuration provided by Lovely Systems. With this buildout and the valentine.remoteinclude enabled on a plone trunk builout we where enable to render a normal plone page where nginx assembled the calendar portlet with the rest of the page.

Tom and I couldn't figure out how to get the information from a portlet from which context the "mapping" (portlet storage) and then the portlet was fetched we where not able to generate urls for context specific portlets other then the root. This information seems to be hidden by the PortletFetcher in Plone. Ideas on how this could be solved are welcome.

With your help I think we can create a good SSI solution for Plone which would enable us to include structure and content in the page from different servers and have it assembled before sent to the user. This would be one step in the direction of using the right tool for the job and not put everything in Plone.

Technorati Tags: plone, zope, nginx, ssi, snowsprint