Friday, July 4, 2014

AttributeError: render from plone.app.i18n.locales.languageselector

After migrating a Plone 3.3 site to Plone 4.3.3, the language selector refused to display:

error while rendering plone.app.i18n.locales.languageselector 

The log showed:

2014-07-04 10:39:11 ERROR plone.app.viewletmanager rendering of plone.portalheader in plone.app.i18n.locales.languageselector fails: render
Traceback (most recent call last):
  File "/Users/kees/.buildout/eggs/plone.app.viewletmanager-2.0.5-py2.6.egg/plone/app/viewletmanager/manager.py", line 105, in render
    html.append(viewlet.render())
  File "/Users/kees/.buildout/eggs/zope.viewlet-3.7.2-py2.6.egg/zope/viewlet/viewlet.py", line 59, in render
    raise AttributeError("render")
AttributeError: render


After googling for it, i found that a similar issue had existed in plonetheme.classic: https://dev.plone.org/ticket/12007 which referred to this commit: https://github.com/plone/plonetheme.classic/commit/3f36218d7b7e62a29fb67191eb6af49dd8242f2e

So i did an analogous change, replacing my existing viewlet registration:

           name="plone.app.i18n.locales.languageselector"
       for="*"
       manager="plone.app.layout.viewlets.interfaces.IPortalHeader"
       layer=".interfaces.IThemeSpecific"
       class="Products.LinguaPlone.browser.selector.TranslatableLanguageSelector"
       permission="zope.Public"
       />

With this:

 
               name="plone.app.i18n.locales.languageselector"
         for="*"
         manager="plone.app.layout.viewlets.interfaces.IPortalHeader"
         layer="argh.plonetheme.browser.interfaces.IThemeSpecific"
         class="Products.LinguaPlone.browser.selector.TranslatableLanguageSelector"
         template="locales/browser/languageselector.pt"
         permission="zope.Public"
         />
 

That fixed it.

Monday, June 2, 2014

Bitbucket's fluid layout: Where's the repository administration screen?

Under "settings", lower left corner of your screen. (Or via ${repo_url}/admin)

Friday, May 23, 2014

"Show Package Contents" in Mavericks

Before Mac OSX 10.9, you could "secondary click" an item in the Applications to get a menu with the option "Show Package Contents". In Mavericks, this option was removed from the menu.

In order to inspect the package contents, you can use the terminal:
$ cd /Applications
$ ls
...
MyApp
$ cd MyApp
$ ls
...
MyApp.app
...
$ cd MyApp.app
$ ls
Contents
$ cd Contents
$ ls
... 
$ open .

This last command will open the package contents in the Finder.
 

Tuesday, September 3, 2013

Python 2.4 bootstrapping


If you still have Plone 3 sites, most likely you will encounter issues when running bootstrap. At Four Digits, Ralph tweaked the bootstrap.py a bit to make it work.
If '/usr/bin/python2.4 python2.4 bootstrap.py' yields things like:
pkg_resources.VersionConflict: (setuptools 0.6c11 (/tmp/tmpSXDs7g/setuptools-0.6c11-py2.4.egg), Requirement.parse('setuptools>=0.7'))
and then you use the new buildout 2 bootstrap and you get a syntax error, and you fix that and then you get other errors, this alternative bootstrap.py might help:

##############################################################################
#
# Copyright (c) 2006 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Bootstrap a buildout-based project

Simply run this script in a directory containing a buildout.cfg.
The script accepts buildout command-line options, so you can
use the -c option to specify an alternate configuration file.
"""

import os, shutil, sys, tempfile, urllib, urllib2, subprocess
from optparse import OptionParser

if sys.platform == 'win32':
    def quote(c):
        if ' ' in c:
            return '"%s"' % c  # work around spawn lamosity on windows
        else:
            return c
else:
    quote = str

# See zc.buildout.easy_install._has_broken_dash_S for motivation and comments.
stdout, stderr = subprocess.Popen(
    [sys.executable, '-Sc',
     'try:\n'
     '    import ConfigParser\n'
     'except ImportError:\n'
     '    print 1\n'
     'else:\n'
     '    print 0\n'],
    stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()
has_broken_dash_S = bool(int(stdout.strip()))

# In order to be more robust in the face of system Pythons, we want to
# run without site-packages loaded.  This is somewhat tricky, in
# particular because Python 2.6's distutils imports site, so starting
# with the -S flag is not sufficient.  However, we'll start with that:
if not has_broken_dash_S and 'site' in sys.modules:
    # We will restart with python -S.
    args = sys.argv[:]
    args[0:0] = [sys.executable, '-S']
    args = map(quote, args)
    os.execv(sys.executable, args)
# Now we are running with -S.  We'll get the clean sys.path, import site
# because distutils will do it later, and then reset the path and clean
# out any namespace packages from site-packages that might have been
# loaded by .pth files.
clean_path = sys.path[:]
import site  # imported because of its side effects
sys.path[:] = clean_path
for k, v in sys.modules.items():
    if k in ('setuptools', 'pkg_resources') or (
        hasattr(v, '__path__') and
        len(v.__path__) == 1 and
        not os.path.exists(os.path.join(v.__path__[0], '__init__.py'))):
        # This is a namespace package.  Remove it.
        sys.modules.pop(k)

is_jython = sys.platform.startswith('java')

setuptools_source = 'http://peak.telecommunity.com/dist/ez_setup.py'
distribute_source = 'http://python-distribute.org/distribute_setup.py'


# parsing arguments
def normalize_to_url(option, opt_str, value, parser):
    if value:
        if '://' not in value:  # It doesn't smell like a URL.
            value = 'file://%s' % (
                urllib.pathname2url(
                    os.path.abspath(os.path.expanduser(value))),)
        if opt_str == '--download-base' and not value.endswith('/'):
            # Download base needs a trailing slash to make the world happy.
            value += '/'
    else:
        value = None
    name = opt_str[2:].replace('-', '_')
    setattr(parser.values, name, value)

usage = '''\
[DESIRED PYTHON FOR BUILDOUT] bootstrap.py [options]

Bootstraps a buildout-based project.

Simply run this script in a directory containing a buildout.cfg, using the
Python that you want bin/buildout to use.

Note that by using --setup-source and --download-base to point to
local resources, you can keep this script from going over the network.
'''

parser = OptionParser(usage=usage)
parser.add_option("-v", "--version", dest="version",
                          help="use a specific zc.buildout version")
parser.add_option("-d", "--distribute",
                   action="store_true", dest="use_distribute", default=False,
                   help="Use Distribute rather than Setuptools.")
parser.add_option("--setup-source", action="callback", dest="setup_source",
                  callback=normalize_to_url, nargs=1, type="string",
                  help=("Specify a URL or file location for the setup file. "
                        "If you use Setuptools, this will default to " +
                        setuptools_source + "; if you use Distribute, this "
                        "will default to " + distribute_source + "."))
parser.add_option("--download-base", action="callback", dest="download_base",
                  callback=normalize_to_url, nargs=1, type="string",
                  help=("Specify a URL or directory for downloading "
                        "zc.buildout and either Setuptools or Distribute. "
                        "Defaults to PyPI."))
parser.add_option("--eggs",
                  help=("Specify a directory for storing eggs.  Defaults to "
                        "a temporary directory that is deleted when the "
                        "bootstrap script completes."))
parser.add_option("-t", "--accept-buildout-test-releases",
                  dest='accept_buildout_test_releases',
                  action="store_true", default=False,
                  help=("Normally, if you do not specify a --version, the "
                        "bootstrap script and buildout gets the newest "
                        "*final* versions of zc.buildout and its recipes and "
                        "extensions for you.  If you use this flag, "
                        "bootstrap and buildout will get the newest releases "
                        "even if they are alphas or betas."))
parser.add_option("-c", None, action="store", dest="config_file",
                   help=("Specify the path to the buildout configuration "
                         "file to be used."))

options, args = parser.parse_args()

if options.eggs:
    eggs_dir = os.path.abspath(os.path.expanduser(options.eggs))
else:
    eggs_dir = tempfile.mkdtemp()

if options.setup_source is None:
    if options.use_distribute:
        options.setup_source = distribute_source
    else:
        options.setup_source = setuptools_source

if options.accept_buildout_test_releases:
    args.insert(0, 'buildout:accept-buildout-test-releases=true')

try:
    import pkg_resources
    import setuptools  # A flag.  Sometimes pkg_resources is installed alone.
    if not hasattr(pkg_resources, '_distribute'):
        raise ImportError
except ImportError:
    ez_code = urllib2.urlopen(
        options.setup_source).read().replace('\r\n', '\n')
    ez = {}
    exec ez_code in ez
    setup_args = dict(to_dir=eggs_dir, download_delay=0)
    if options.download_base:
        setup_args['download_base'] = options.download_base
    if options.use_distribute:
        setup_args['no_fake'] = True
        if sys.version_info[:2] == (2, 4):
            setup_args['version'] = '0.6.32'
    ez['use_setuptools'](**setup_args)
    if 'pkg_resources' in sys.modules:
        reload(sys.modules['pkg_resources'])
    import pkg_resources
    # This does not (always?) update the default working set.  We will
    # do it.
    for path in sys.path:
        if path not in pkg_resources.working_set.entries:
            pkg_resources.working_set.add_entry(path)

cmd = [quote(sys.executable),
       '-c',
       quote('from setuptools.command.easy_install import main; main()'),
       '-mqNxd',
       quote(eggs_dir)]

if not has_broken_dash_S:
    cmd.insert(1, '-S')

find_links = options.download_base
if not find_links:
    find_links = os.environ.get('bootstrap-testing-find-links')
if not find_links and options.accept_buildout_test_releases:
    find_links = 'http://downloads.buildout.org/'
if find_links:
    cmd.extend(['-f', quote(find_links)])

if options.use_distribute:
    setup_requirement = 'distribute'
else:
    setup_requirement = 'setuptools'
ws = pkg_resources.working_set
setup_requirement_path = ws.find(
    pkg_resources.Requirement.parse(setup_requirement)).location
env = dict(
    os.environ,
    PYTHONPATH=setup_requirement_path)

requirement = 'zc.buildout'
version = options.version
if version is None and not options.accept_buildout_test_releases:
    # Figure out the most recent final version of zc.buildout.
    import setuptools.package_index
    _final_parts = '*final-', '*final'

    def _final_version(parsed_version):
        for part in parsed_version:
            if (part[:1] == '*') and (part not in _final_parts):
                return False
        return True
    index = setuptools.package_index.PackageIndex(
        search_path=[setup_requirement_path])
    if find_links:
        index.add_find_links((find_links,))
    req = pkg_resources.Requirement.parse(requirement)
    if index.obtain(req) is not None:
        best = []
        bestv = None
        for dist in index[req.project_name]:
            distv = dist.parsed_version
            if distv >= pkg_resources.parse_version('2dev'):
                continue
            if _final_version(distv):
                if bestv is None or distv > bestv:
                    best = [dist]
                    bestv = distv
                elif distv == bestv:
                    best.append(dist)
        if best:
            best.sort()
            version = best[-1].version

if version:
    requirement += '=='+version
else:
    requirement += '<2dev -c="" 0:="" a="" above="" add="" already="" any="" apparently="" args.append="" args="" back="" bootstrap="" br="" buildout="" by="" c="" clean="" cmd.append="" cmd="" command="" directory="" easy_install.="" egg="" eggs_dir="" else:="" env="" error="" errors="" exitcode="" for="" function="" if="" import="" in="" install="" into="" is="" is_jython:="" isn="" it="" main="" message="" n="" none:="" not="" occurred="" ook="" options.config_file="" options.eggs:="" otherwise="" output="" prefer="" prefers="" print="" provided="" push="" requirement="" s="" shutil.rmtree="" subprocess="" sys.executable="" sys.exit="" sys.stderr.flush="" sys.stdout.flush="" t="" temporary="" that="" the="" there="" this="" to="" trying="" up="" was="" we="" were="" when="" windows="" would="" ws.add_entry="" ws.require="" zc.buildout.="" zc.buildout.buildout.main="" zc.buildout.buildout="">
Credits for this go to Ralph.

Wednesday, July 17, 2013

Reusing code between views and viewlets

You may wonder, as i did today, how you can re-use code from your View inside a Viewlet. Just to help out the occasional googler, i'm recording my solution here.

Any Viewlet has its View as an attribute (see ViewletBase's __init__ method). So in your Viewlet class, you can do something like:
Class MyViewlet(ViewletBase):
    ...
    def reused_method(self):
            return self.view.original_method()

Thursday, July 11, 2013

try-except HTTPError and URLError


urllib2's HTTPError subclasses URLError, so the bit of code below would never get to the second except statement, because that error would aready be caught in the first except. To get this code to work, reverse the order.



            try:
                response = urlopen(url)
            except URLError:
                # This happens if the server can't be reached.
                # Most likely the service is down, in this case we don't want
                # to do anything.
                # Another possibility is that we have the API url wrong.
                self.url_errors.append(value)
                return True
            except HTTPError:
                # as Flattr API does return an error code (404 not found) when
                # looking for users that do not exist, urllib2 treats that as
                # an error, so no need to investigate or differentiate between
                # that and a normal HTTP error. Both are enough to not validate
                # a Flattr user.
                self.http_errors.append(value)
                return False


Wednesday, June 19, 2013

Update your robots.txt, and nginx.conf

[update: not sure if robots.txt is respected]
We recently had an interesting afternoon when our servers were all but brought down by a crawler called 80legs. This crawler showed no mercy on our poor site and bore down with great vengeance and furious anger on articles so old that the cache didn't have them.
We get a lot of crawlers, if you've spent hours gazing at your instance-Z2.logs like i have (beats a washing machine!), you've seen a lot of them. What was surprising was the amount of traffic it generated: it was more like a DDoS attack than a crawling service.
The thing with 80legs is: Crawls are initiated by their users. Any user. There is no check to see if the user is affiliated with the site to be crawled. You can create an account with a fake mailaddress. If they have, as they boast, 50,000 servers across the world getting 10,000 pages (the maximum amount on a free account) in no time, i can imagine other sites also having trouble with this. 
So after the initial quick fix (blocking the user agent '008' in nginx), i contacted the company to ask what measures they take to keep unthinking (or even malicious) users from bringing down sites. The answer was swift, simple and sucky: nothing. They apologized, and added our site to a list.
80legs says they obey robots.txt, and i think it's wise that you update yours. But the wikipedia page has some examples of cases where robots.txt was not respected, and a Twitter search indicates there are still problems. So the best approach seems to be not to rely on robots.txt, and set up your webserver / cache to ignore requests from this user agent.