Grok Status Update part 3

  • By Martijn Faassen
  •  • 
  • 2008-06-11
  •  • 
  • Tags: 
  • grok

Lots more is going on in the Grok world, so the Grok Status Update has received a part 3. See also part 1 and part 2.


Thanks to work at the Grokkerdam sprint, Grok 0.13 will contain an IOrderedContainer implementation besides the normal container: grok.OrderedContainer.


We realized during the Grokkerdam sprint that we should allow the user to pass the permission class directly to grok.require, instead of having to pass the permission name. Using permission names is still possible (and sometime necessary if the permission isn't defined by Grok itself), but in Grok 0.13 it will also be possible to pass the permission class directly:

class MyPermission(grok.Permission):"my.permission")

class MyView(grok.View):

menus in Grok

Jan-Wijbrand and myself discussed what menus in Grok could look like a week or two ago. We found many parallels with viewlet managers (menu itself) and viewlets (menu entries), and we think we can build this on top of viewlets. We need to work out a more detailed design proposal and discuss it on grok-dev next.

grokcore.component release

At the post-PyCon sprint, Brandon Craig Rhodes and Robert Marianski worked on extracting generic bits from Grok into a separate package called grokcore.component. At the Grokkerdam sprint, Philipp von Weitershausen polished it off, merged the branch that makes the Grok trunk depend on it, and released it to PyPI.

grokcore.component is compatible with Zope 3 and also with Zope 2. It is more light-weight than Grok itself, so it's easier to integrate in existing projects. Various Zope 3 and Zope 2 developers have started using this package in their own projects.


At the Paris Plone sprint, held in the week before the Grokkerdam sprint, a new package five.grok was created. This package aims to provide Grok functionality to Zope 2. It builds on grokcore.component, and extends its functionality with other things like view support. During the Grokkerdam sprint Eric Casteleijn continued work on five.grok, adding tests and updating it as grokcore.component itself was updated.

The task is now to get a dedicated set of volunteers who want to bring five.grok up to speed. The idea is that five.grok will as much as possible make available Grok's APIs in Zope 2. It won't engage in the invention of new APIs; that is for other packages which build on this.

directive refactoring

A large project was completed at the Grokkerdam sprint by Philipp von Weitershausen and Jan-Wijbrand Kolman. During the Snow sprint in january, I noticed quite a bit of regularity in the way directives were used in Grok. I figured there was a way to abstract this out and push it into our Martian configuration library, so on the train trip back from the Snow sprint, I started a project to implement this in Martian.

Philipp and Jan-Wijbrand extended this work at the Grokkerdam sprint, started using it in grokcore.component and Grok itself, cleaning up Grok's grokkers quite a bit.

At the end of the sprint we reviewed this work and started work on the next step of this pattern: declare exactly what directives a grokker uses in the Grokker. This cleans up the code even more, and should make it much easier for the Grok introspector to deduce useful information for the introspector UI.

Philipp continued this work after the sprint. This is now merged into the Grok trunk as well (and grokcore.component uses it too, already released). Since then, we noticed another pattern in the way classes were grokked that actually register the methods of these classes. Philipp set out to work on this too, and this resulted in a new part of Martian called the MethodGrokker, which codifies this pattern. This further cleans up Grok.

Since then, I've further extended Martian. It now has a nicer tutorial, and it uses the new directive infrastructure to define grokkers as well. This makes a grokker look like any grokked class -it derives from a base class and has a few directives.

All this work will land in Grok 0.13.


Joachim Schmitz and myself worked on a demonstrator project to see how we could construct a powerful CRUD framework on top of Grok, automating the user interface. This is code that typically needs a lot of pluggability, and pluggability is where the Zope component architecture shines. Hopefully we'll see more progress on CRUD in Grok in the future.

EuroPython Grok sprint

We will be having another Grok sprint after EuroPython this year. We are looking for people to participate. If you want to join in, please add your name here: