Weblog
A first look at Erik Rose: Plone 3 for Education
Erik Rose has written a book about: Plone 3 for Education. Here are my first impressions.
Plone 3 for Education is targeted at people working in education or in other larger organizations. You are the webmaster responsible for one or more websites of the organization. You are comfortable using Plone daily, but there just never is time to do everything that is needed. You want to delegate responsibilities to other users and wonder what is the best way to do that. The website needs some extra functionality and you would like to use an existing product for that; but which one is the safe bet for the future? And the website looks a bit outdated and could use some visual freshness. You have done a few tweaks in the Zope Management Interface, but have also heard that this is not the best way. So how do you make a nice theme these days?
If you recognize yourself in that description, then this book is for you. Hardened Plone programmers will not find much news here; still, most chapters give info about how best to use some third party products, like Plone4Artists Calendar and Faculty/Staff Directory. If you know what these products can do, you become a better consultant; and you know when to pick one of these products off the shelf instead of programming something totally new.
As the preface says, most chapters stand on their own. So the first thing I did, was to take on chapter 7: Creating Forms Fast. This is about PloneFormGen. My experience with PloneFormGen was mostly how to add it in a buildout, as at Zest Software we use this for quite a lot of clients. I do not think I have ever actually used it myself. So this looked like an interesting chapter to start with.
PloneFormGen is well maintained by Steve McMahon, who was one of the reviewers of this book, so you can be pretty sure the information in this chapter is correct.
The chapter starts out by telling you to "install PloneFormGen by adding Products.PloneFormGen to your buildout, as per usual." So you are expected to know a bit about buildout already. Earlier chapters may explain a bit more about this. The chapter then continues with a few very practical steps to take in the css and javascript registry when you want to support adding Rich Text or Date/Time fields on forms. Good to know.
Erik then takes you through your first steps with PloneFormGen, adding a FormFolder in the site and doing a bit of editing there. He presents all form fields that you can add. He explains that you should edit the default Mailer form action and set a recipient email address there, otherwise form submission will fail. When you add a Save Data Adapter, to store the submissions in the zodb, you get two valuable tips. Always keep a mailer adapter as backup in case something goes wrong and you lose the saved data; and do not remove or reorder fields when the form is already live, as the saved data will not get changed to fit.
The chapter gives a short recommendation on when to use PloneFormGen and when to create an Archetypes content type. Then it ends with giving you a taste of the flexibility of PloneFormGen. You can use it to create online tests for your students. You can use it to create a simple form (or a complex one if your organization needs that) as front end for creating news items (or other content items).
I'll write another review with a look at the other chapters later. If those chapters are similar to this one (and I have peeked already), then this looks like a very practical book. It presents clear goals, with step-by-step instructions to reach them, without magically sounding jargon, and with some hard earned wisdom so you can step around the common pitfalls. I think a lot of people could benefit from this.
Disclaimer: I got this book for free from Packt Publishing in exchange for a review; and ordering the book via one of the links in this article will land me some money.
Indexes in catalog.xml considered harmful
Do not add indexes in catalog.xml. Do that in a separate import or upgrade step. Read on for how to do that; I will throw in some general GenericSetup best practices along the way.
Basic use of catalog.xml
Using GenericSetup you can add indexes and metadata columns to the portal_catalog with a catalog.xml file like this:
<!--?xml version="1.0"?--> <object name="portal_catalog" width="300" height="150">
<index name="getSomething" meta_type="KeywordIndex">
<indexed_attr value="getSomething"></indexed_attr>
</index>
<column value="getSomething"></column></object>
Specifying an index will add an index for getSomething in the portal_catalog so you can search on it. Specifying a column will add getSomething to the metadata of the catalog brains, so you can ask a brain what his value is for getSomething. These are very different use cases, so before you add both an index and a column you may want to think if you really need them both or if one of them is enough.
Anyway, specifying a column here is fine. Nothing wrong with it. Do note that when you add a column here this does not make getSomething available in the current brains in the catalog. You will need to do a reindex; a clear and rebuild of the catalog would do it, but it may be enough to find and reindex items of one specific content type that has this field. Depending on your specific situation this may or may not be an issue.
What happens with indexes?
What is almost never a good idea however, is specifying an index here. What this does is it creates the index in the portal_catalog. The index is not filled automatically, so you will have to reindex it manually (or write some code for that). But what happens the next time you reinstall your product or reapply your profile? The index gets removed and recreated. So the index is empty and you will need to reindex it manually again! That is not very handy.
This might be fixable in the GenericSetup import handler for catalog.xml. But this is hard to do as it is currently not possible to verify without a doubt that the index that is currently in the portal_catalog has the same configuration as specified in the catalog.xml. For example, the id might be the same but the existing index might be a FieldIndex and catalog.xml might specify a KeywordIndex. This specific check might be doable, but there are other indexes for which this is not so simple.
Import handler
So, what do you do instead? You add an import handler. I have done that in several products, so instead of copy-pasting code from one of those products I might as well copy-paste it from my weblog. :-)
Write an import step in setuphandlers.py:
import logging
from Products.CMFCore.utils import getToolByName
# The profile id of your package:
PROFILE_ID = 'profile-your.product:default'
def add_catalog_indexes(context, logger=None):
"""Method to add our wanted indexes to the portal_catalog.
@parameters:
When called from the import_various method below, 'context' is
the plone site and 'logger' is the portal_setup logger. But
this method can also be used as upgrade step, in which case
'context' will be portal_setup and 'logger' will be None.
"""
if logger is None:
# Called as upgrade step: define our own logger.
logger = logging.getLogger('your.package')
# Run the catalog.xml step as that may have defined new metadata
# columns. We could instead add to
# the registration of our import step in zcml, but doing it in
# code makes this method usable as upgrade step as well. Note that
# this silently does nothing when there is no catalog.xml, so it
# is quite safe.
setup = getToolByName(context, 'portal_setup')
setup.runImportStepFromProfile(PROFILE_ID, 'catalog')
catalog = getToolByName(context, 'portal_catalog')
indexes = catalog.indexes()
# Specify the indexes you want, with ('index_name', 'index_type')
wanted = (('getSomething', 'FieldIndex'),
('getAnother', 'KeywordIndex'),
)
indexables = []
for name, meta_type in wanted:
if name not in indexes:
catalog.addIndex(name, meta_type)
indexables.append(name)
logger.info("Added %s for field %s.", meta_type, name)
if len(indexables) > 0:
logger.info("Indexing new indexes %s.", ', '.join(indexables))
catalog.manage_reindexIndex(ids=indexables)
def import_various(context):
"""Import step for configuration that is not handled in xml files.
"""
# Only run step if a flag file is present
if context.readDataFile('your_package-default.txt') is None:
return
logger = context.getLogger('your.package')
site = context.getSite()
add_catalog_indexes(site, logger)
If you need to replace an existing FieldIndex with a KeywordIndex this code is not enough, but we ignore that possibility here.
The rest should be nothing new, but let's make it clear and explicit by showing everything here.
Register your GenericSetup code
I usually end up moving the registration of GenericSetup profiles, import and upgrade steps in a separate zcml file called profiles.zcml. We need to include that in our configure.zcml:
We register our profile and our steps in profiles.zcml:
metadata.xml
Create a profiles/default directory if this does not exist yet. This must have a metadata.xml file like this:
1001
The version number should be an integer. This profile version has nothing at all to do with the number in our version.txt or setup.py, but that is a different discussion. The destination number in our last upgrade step registration must match this metadata version.
Flag file
When you apply a GenericSetup profile or (re)install a product, every import step defined by any package is called. One step looks for a catalog.xml file within the profile directory of the profile that is being applied and exits if it is not there; another looks for a skins.xml and exits if it is not there. Our own import step must do the same, otherwise our code is executed far too often, even when our product is not installed.
As seen above, our import_various import handler starts with this check:
if context.readDataFile('your_package-default.txt') is None:
return
So we must add a file with the name your_package-default.txt in profiles/default. The contents don't really matter; it can be something like this:
Flag file for the import handler of your.package
Sprint report Sunday
- People have been signing contributor agreements. We got 23 new core Plone contributors this weekend. Fantastic!
- Deco: testing javascript stuff (30 percent coverage currently), describing use cases of deco UI, see what differences will be with Plone 4 and 5.
- slc.linguatools: interface improvements, rewrite from scratch, zc3 based, making sure functionalities are working.
- funkload buildout, measure nightly performance testing: it works, except creation of a Plone Site currently fails (please help fix this).
- collective.hostout: worked on multiple python versions, completed plugin for mr.developer integration, database integration, fixed bugs, helped out video guys.
- amberjack: show to user which tours are completed and which not, translation work, completed some of the tours, talked about using amberjack in third party projects.
- Trying to revitalize plone Italian community, talking, user map on google.
- Content import and export, transmogrifier: using zope.brokenfile, dependency graphs, store everything on portal.
- mr.git: commands, detailed readme.
- testing crawler: create a very small tests.py file that finds all tests
- QA: testing packages against different Plone versions with buildbot.
- fluxbin application/tool: routing, website
- blob support: CMFEditions, fixed bugs, 1 line of zcml and 3 lines of code will get you blob support.
- Singing and Dancing: Italian translation, discussion on users handling.
- Plone Marketing material: get existing material and links.
- Video: annotations for storing height, width, etc. We think various sizes can be stored, collective.flowplayer work. We will be sprinting at the open society, near the Basilica, with food. Contact us. Send mail to participants list.
- Roadrunner: working now with dexterity cts, working with z3c.autoinclude, preparing 0.3 release. Check out the dev version and try it out.
- Banjo: point and click improvements.
- Limi: Plone now has less css files, move files to the Plone Classic Theme. Some strategic talking. How to improve templating story, add-on story, which things to move to WSGI, what we can kill off in Zope 2, how to handle at versions dexterity references, what parts of CMF to keep.
- 3rd party products: PloneSoftwareCenter, ZopeSkel, Scrawl, PressRelease, several others.
First day sprint report
Plone conference 2009
- ZopeSkel ui has 100% test coverage now
- folder based folder view has improved, should help get CMF 2.2 closer
- OTTO: new logo, example package
- getpaid: testing new branch, select currency in setup panel, got more ideas
- roadrunner: test coverage added, newer zope.testing (need more info, please let me know), if you care about Plone 2.5 let me know; tomorrow will work on z3c.autoinclude.
- hostout: getting tests complete, installing and initializing server, work on supervisor
- LinguaTools: improving test coverage and fixed some bugs because of that, jquery integration.
- Third party products for Plone 4: mr.parker to check if a package has only one owner on pypi; updating CacheSetup, Poi, AddRemoveWidget, DataGridField, collective.ads, collective.classifieds, collective.discuss, Scrawl, Collage, ref browser widget, Maps, uploadify, flash upload, image editor, ploneboard.
- Social media: moving plone.org to WordPress (joke), brainstorming, writing.
- Versioning and CMFEditions for dexterity and East Asian Language.
- AGX: added UML 2.2 profile support, needed for generation chain, work on transformation.
- Singing and Dancing newletter package: closing bugs, blueprinting some new features, refactoring for features that we want, work on letting portal users and groups be subscribers.
- Video sprint: cleaned up Plumi buildout, translated in Indonesia (also Plone 3 core), blob work (come hang out with us if you know about blobs), plonevideosuite buildout (in collective), uploadify integration, TinyMCE integration to render as a player, creative commons licenses. Tomorrow pod casting, metadata extraction, nginx.
- Banjo: getting up to speed getting Deliverance installed and comfortable with it, looking at jqGrid for better UI integration.
- Amberjack: finished tour number 9, fixed problems with kupu, great new things, graphical elements to make it more usable, translations for Slovenian, Italian, Spanish and Polish.
- Plone social RPX platform for SSO, like with google, facebook. Profile editing view. Code is at bit bucket.
- Integration of git for Plone dev tool chain. Svn upstream, git locally, caching, concept is finished and we started working, shorter-named repositories in mr.developer.
- Limi: I have written zero lines of css today, helped people get Plone 4, lot of discussions, I released firefox 3.6 beta 1, take an image and drop it into Deco is now possible with that, ZMI security page does not lock up anymore. xdv, theme discussions.
- xdv fixed on Plone 4.
- Deco: some dexterity issues, fixes.
- Blob types, LinguaPlone adding tests, ATContentTypes can remain unchanged to keep working in Plone 3 and 4.
- Funkload used for load testing of core Plone.
Tomorrow we start at 9:00.
Migrating a Product to Plone 4.0
Some preliminary results and ideas based on first steps to get Products.Poi working on Plone 4 (not there yet).
Setup your buildout
Soon: add Plone==4.0a1 to the eggs in your buildout.cfg
Now: add your egg to the development buildout: http://tr.im/TryPlone4
Example buildout.cfg for Products.Poi
[buildout]
extends = buildout.cfg
auto-checkout +=
Products.Poi
Products.AddRemoveWidget
Products.DataGridField
[sources]
Products.Poi = svn https://svn.plone.org/svn/collective/Products.Poi/trunk
Products.AddRemoveWidget = svn https://svn.plone.org/svn/archetypes/Products.AddRemoveWidget/trunk
Products.DataGridField = svn https://svn.plone.org/svn/archetypes/Products.DataGridField/trunk
[instance]
eggs +=
Products.Poi
Things to test
- Does bin/buildout work?
- Does the instance start up in the foreground?
- Can you install your product?
- Can you create/view your content type?
- Do the tests pass?
What to change
http://plone.org/documentation/migration
BACKWARDS_COMPATIBILITY.txt in Plone package:
Highlights
- Python2.6, Zope 2.12, CMF 2.2
- No more global_defines.pt
Poi Example 1
ImportError: No module named Interface
- Remove any imports of the Interface package.
- Remove any __implements__ lines from your content types.
- http://dev.plone.org/collective/changeset/100276
Poi Example 2
ImportError: No module named GlobalTranslationService
- use zope.i18n
Old:
from Products.PageTemplates.GlobalTranslationService \
import getGlobalTranslationService
ts = getGlobalTranslationService()
msg = ts.translate('Poi', msg, context=self.context)
New:
from zope.i18n import translate msg = translate(msg, 'Poi', context=self.request)
[Update: you need to pass the request instead of the context.]
Plone 3.x and 4?
Compatibility can work:
try:
from beer import Grolsch
except ImportError:
# BBB
from beer import Heineken
or maybe not:
install_requires=[
'Plone>=4.0dev',
],