"Client has seen newer transactions than server!"

I got this error after moving a database from one server to the other on a ZODB client-server setup. The instances (ZODB clients) would be up and running, but completely unresponsive. It can be fixed by removing the "instance" parts completely and re-running buildout.

nginx buildout failing at openssl on Mac OS X Lion

The error message was:

make[1]: *** [objs/src/event/ngx_event_openssl.o] Error 1
make: *** [build] Error 2
nginx-build: Command failed with exit code 2: make

Running the steps suggested here solved the problem: http://code.google.com/p/phusion-passenger/issues/detail?id=650#c2

How to disable comments on comments

The threaded view of plone.app.discussion's comment item tends to look a bit confusing when there are many threads. Ons possible solution would be disallowing comments on comments, so you'd just get a flat list of items. This is similar to how many other commenting systems work (like Facebook and Twitter, for example).

Comments on comments can be disabled in the ZMI: go to 'portal_types' -> 'Discussion Item', uncheck "Allow Discussion".

Goodbye GW20e, hello Freitag

After almost four years at Goldmund, Wyldebeast and Wunderliebe, the time has come to move on.

In december i will start a new job at the weekly magazine Der Freitag in Berlin. I look forward to working with our small team of in-house web developers. It's a good place to put some of my skills to work, and i expect to learn a lot of new things too. And of course i look forward to Berlin.

Life without GW20e will not be the same. It's been a truly amazing time, and i feel lucky to have been part of it. A big thank-you is due for all the things i've learned, and for all the good times we've had.

I'll still be posting my (possibly) interesting (to some) Plone stuff here.

Migrate files from Compound-/ArrayField to File objects in folder

A migration script. The use case is a site which currently allows users to add a list of files to custom objects. I want to make these objects folderish, extract the files from field and store them as regular Plone files, so we can migrate to Plone 4 and use blobstorage.

import transaction
from zope.component import queryUtility
from Acquisition import aq_parent

from plone.i18n.normalizer.interfaces import IIDNormalizer
from Products.CMFCore.utils import getToolByName
from Products.CMFPlone.utils import _createObjectByType
from Products.CMFPlone.utils import safe_unicode
from Products.Five.browser import BrowserView
from Products.Five.browser.pagetemplatefile import ViewPageTemplateFile

class MyContentTypeMigrationView(BrowserView):
    """ Migrate from non-folderish objects with files in CompoundField/ArrayField 
    to folderish (containing ATFile objects)."""

    __call__ = ViewPageTemplateFile("templates/migrate_files.pt")

    def __init__(self, *args, **kwargs):
        super(MyContentTypeMigrationView, self).__init__(*args, **kwargs)
        self._catalog = getToolByName(self.context, 'portal_catalog')
        self._file_counter = 0
        self._mycustomtype_counter = 0
        self._normalizer = queryUtility(IIDNormalizer)

    def rename(self, obj):
        """Rename object: strip trailing '.pdf', at least from id. """
        stripped_extensions = ['.pdf',]
        for extension in stripped_extensions:
            # No need to set a Title yet, not sure if we have to at all.
            # obj.setTitle(obj.Title().rstrip(extension))
            parent = aq_parent(obj)
            oid = obj.getId()
            if oid.endswith(extension):
                parent.manage_renameObject(oid, oid.rstrip(extension))
                changed = True

    def create_file_objects(self, obj):
        """Read files from 'documents' CompoundField, create ATFile objects and
        delete files from 'documents' CompoundField. 
        
        """
        files = obj.getDocuments()
        for field_file in files:
            # file from CompoundField may be empty
            if field_file is not None:
                filename = field_file.filename
                if not filename:
                    # filename may be empty, in that case take it from Plone
                    # object url
                    filename = field_file.absolute_url().split('/')[-2]
                file_field_id = field_file.id()
                try:
                    # filename must be unicode
                    filename_safe_uni = safe_unicode(filename)
                    new_id = self._normalizer.normalize(filename_safe_uni)
                    self.context.plone_log("Creating file %s (%s)" % 
                        (filename, file_field_id) )
                    if hasattr(obj, new_id):
                        self.context.plone_log("Object with id %s exists, skipping" % new_id)
                    else: 
                        _createObjectByType('File', obj, id=new_id, title=filename)
                        self.context.plone_log("File object created")
                        file_object = obj.get(new_id)
                        file_object.setFile(field_file)
                        file_object.reindexObject()
                        self._file_counter += 1
                        self.context.plone_log("File content set (#%d)" % self._file_counter)
                        # "Delete" file from CompoundField
                        delattr(obj, file_field_id)
                        self.context.plone_log("File deleted from CompoundField")
                except:
                    self.context.plone_log("ERROR creating / setting / deleting file")
                    import pdb; pdb.set_trace()

    def html(self):
        """Render something"""
        html = ''
        brains = self._catalog(
            portal_type='MyCustomType',
            )
        for brain in brains:
            obj = brain.getObject()
            self.rename(obj)
            self.create_file_objects(obj)
            obj.reindexObject()
            # commit subtransaction
            transaction.get().commit(True)
            self._mycustomtype_counter += 1
            self.context.plone_log("MyContentType object nr %d)" % self._mycustomtype_counter)
            html += 'migrated <a href="%s">%s</a><br />' % (
                obj.absolute_url(), obj.getId() )
        return html

How to plug into Plone's id (for url) generating mechanism

Plone can convert titles to id's, which are used in the URL. To use this conversion in your own code, use the IIDNormalizer utility.

[edit: removed broken link to Plone's developer documentation, added code snippet]

from zope.component import queryUtility
from plone.i18n.normalizer.interfaces import IIDNormalizer

id = queryUtility(IIDNormalizer).normalize(title)

Plone 3 on Natty: Python 2.4 with PIL

Installing PIL in a (hand-compiled) python2.4 yielded "python "ZLIB (PNG/ZIP) support not available", although i did have zlib1g-dev installed.

Found the answer in http://ubuntuforums.org/showthread.php?t=1751455#post10810486: Natty puts some libs in /usr/lib/x86_64-linux-gnu/, where PIL can't find them. Symlinking helps.