Thoughts: time warp to 2011

02
Nov

Django Facebook user integration with whitelisting

It's recently become quite popular for web sites to abandon the tasks of user authentication and account management, and to instead shoulder off this burden to a third-party service. One of the big services available for this purpose is Facebook. You may have noticed "Sign in with Facebook" buttons appearing ever more frequently around the 'Web.

The common workflow for Facebook user integration is: user is redirected to the Facebook login page (or is shown this page in a popup); user enters credentials; user is asked to authorise the sharing of Facebook account data with the non-Facebook source; a local account is automatically created for the user on the non-Facebook site; user is redirected to, and is automatically logged in to, the non-Facebook site. Also quite common is for the user's Facebook profile picture to be queried, and to be shown as the user's avatar on the non-Facebook site.

This article demonstrates how to achieve this common workflow in Django, with some added sugary sweetness: maintaning a whitelist of Facebook user IDs in your local database, and only authenticating and auto-registering users who exist on this whitelist.

27
Oct

A blood pledge to never vote for Tony Abbott

This is a pledge in blood this man will go.

This is a pledge in blood this man will go.

Two weeks ago, the Gillard government succeeded in passing legislation for a new carbon tax through the lower house of the Australian federal parliament. Shortly after, opposition leader Tony Abbott made a "pledge in blood", promising that: "We will repeal the tax, we can repeal the tax, we must repeal the tax".

The passing of the carbon tax bill represents a concerted effort spanning at least ten years, made possible by the hard work and the sacrifice of numerous Australians (at all levels, including at the very top). Australia is the highest per-capita greenhouse gas emitter in the developed world. We need climate change legislation enactment urgently, and this bill represents a huge step towards that endeavour.

I don't usually publish direct political commentary here. Nor do I usually name and shame. But I feel compelled to make an exception in this case. For me, Tony Abbott's response to the carbon tax can only possibly be addressed in one way. He leaves us with no option. If this man has sworn to repeal the good work that has flourished of late, then the solution is simple. Tony Abbott must never lead this country. The consequences of his ascension to power would be, in a nutshell, diabolical.

So, join me in making a blood pledge to never vote for Tony Abbott.

11
Oct

Geeks vs hippies

The duel to end them all. Who shall prevail?

The duel to end them all. Who shall prevail?

Geeks. The socially awkward, oft-misunderstood tech wizzes that are taking over the world. And hippies. The tree-huggin', peace-n-lovin' ragtags that are trying to save the world, one spliff at a time.

I've long considered myself to be a member of both these particular minority groups, to some extent. I'm undoubtedly quite a serious case of geek; and I also possess strong hippie leanings, at the least. And I don't believe I'm alone, either. Nay — the Geekius Hippius is, in fact, a more common species than you might at first think.

I present here a light-hearted comparison of these two breeds. Needless to say, readers be warned: this article contains high level stereotyping.

04
Oct

Don't trust Facebook with your data

It's been five years since it opened its doors to the general public; and, despite my avid hopes that it DIAF, the fact is that Facebook is not dead yet. Far from it. The phenomenon continues to take the world by storm, now ranking as the 2nd most visited web site in the world (after Google), and augmenting its loyal ranks with every passing day.

I've always hated Facebook. I originally joined not out of choice, but out of necessity, there being no other way to contact numerous friends of mine who had decided to boycott all alternative methods of online communication. Every day since joining, I've remained a reluctant member at best, and an open FB hater to say the least. The recent decisions of several friends of mine to delete their FB account outright, brings a warm fuzzy smile to my face. I haven't deleted my own FB account — I wish I could; but unfortunately, doing so would make numerous friends of mine uncontactable to me, and numerous social goings-on unknowable to me, today as much as ever.

There are, however, numerous features of FB that I have refused to utilise from day one, and that I highly recommend that all the world boycott. In a nutshell: any feature that involves FB being the primary store of your important personal data, is a feature that you should reject outright. Facebook is an evil company, and don't you forget it. They are not to be trusted with the sensitive and valuable data that — in this digital age of ours — all but defines who you are.

18
Jul

World domination by box office cinema admissions

It's no secret that Hollywood is the entertainment capital of the world. Hollywood blockbuster movies are among the most influential cultural works in the history of humanity. This got me thinking: exactly how many corners of the globe have American movies spread to; and to what extent have they come to dominate entertainment in all those places? Also, is Hollywood really as all-powerful a global cinema force as we believe; or does it have some bona fide competition these days?

I spent a bit of time recently, hunting for sets of data that could answer these questions in an expansive and meaningful way. And I'm optimistic that what I've come up with satisfies both of those things: in terms of expansive, I've got stats (admittedly of varying quality) for most of the film-watching world; and in terms of meaningful, I'm using box office admission numbers, which I believe are the most reliable international measure of film popularity.

07
Jul

Kosher and the Land that G-d forgot

Per the laws of kashrut, the Jewish religion prohibits the consumption of meat from many animals and birds. Islam's laws of halal enact very similar prohibitions.

Australia and New Zealand are two countries located very far from the Middle East, the home of Judaism and Islam. Their native wildlife is completely different to that found anywhere else in the world. Of course, since European settlement began, they've been thoroughly introduced to the fauna of the wider world. Indeed, these two countries are today famous for being home to some of the world's largest sheep and cattle populations.

However, let's put aside the present-day situation for now, and take ourselves back in time a thousand or so years. Artificial transcontinental animal transportation has not yet begun. The world's animals still live in the regions that G-d ordained for them to live in. G-d has peppered almost every corner of the globe with at least some variety of kosher birds and mammals. Every major world region, bar one.

My fellow Aussies and Kiwis, I'm afraid the verdict is clear: we are living in the Land that G-d forgot.

30
Jun

Thread progress monitoring in Python

My recent hobby hack-together, my photo cleanup tool FotoJazz, required me getting my hands dirty with threads for the first time (in Python or otherwise). Threads allow you to run a task in the background, and to continue doing whatever else you want your program to do, while you wait for the (usually long-running) task to finish (that's one definition / use of threads, anyway — a much less complex one than usual, I dare say).

However, if your program hasn't got much else to do in the meantime (as was the case for me), threads are still very useful, because they allow you to report on the progress of a long-running task at the UI level, which is better than your task simply blocking execution, leaving the UI hanging, and providing no feedback.

As part of coding up FotoJazz, I developed a re-usable architecture for running batch processing tasks in a thread, and for reporting on the thread's progress in both a web-based (AJAX-based) UI, and in a shell UI. This article is a tour of what I've developed, in the hope that it helps others with their thread progress monitoring needs in Python or in other languages.

29
Jun

FotoJazz: A tool for cleaning up your photo collection

I am at times quite a prolific photographer. Particularly when I'm travelling, I tend to accumulate quite a quantity of digital snaps (although am still working on the quality of said snaps). I'm also a reasonably organised and systematic person: as such, I've developed a workflow for fixing up, naming and archiving my soft-copy photos; and I've also come to depend on a variety of scripts and little apps, that perform various steps of the workflow for me.

Sadly, my system has had some disadvantages. Most importantly, there are too many separate scripts / apps involved, and with too many different interfaces (mix of manual point-and-click, drap-and-drop, and command-line). Ideally, I'd like all the functionality unified in one app, with one streamlined graphical interface (and also everything with equivalent shell access). Also, my various tools are platform-dependent, with most of them being Windows-based, and one being *nix-based. I'd like everything to be platform-independent, and in particular, I'd like everything to run best on Linux — as I'm trying to do as much as possible on Ubuntu these days.

Plus, I felt in the mood for getting my hands dirty coding up the photo-management app of my dreams. Hence, it is with pleasure that I present FotoJazz, a browser-based (plus shell-accessible) tool built with Python and Flask.

01
Jun

On the Torah and the Word of G-d

The Torah — also known as the Old Testament, the Pentateuch, or the Five Books of Moses — is the foundation document of the Jewish religion (among others), and it's regarded by Orthodox Jews (among others) as the infallible Word of G-d. It's generally believed that the Torah in its entirety was conveyed orally to Moses on Mount Sinai, approximately 3,300 years ago; and that Moses transcribed the Torah exactly as it was revealed to him.

Most of the Torah is rock solid: sensible laws; moralistic stories; clear presentation of history; and other important information, such as geneaologies, rituals, and territorial boundaries. However, sometimes them five books throw some serious curve balls. I've selected here a few sections from the wonderful O.T, that in my opinion are so outrageously messed up, that they cannot possibly be the Divine Word. I believe in G-d, one hundred percent. But I see no reason to believe that these particular passages have a Divine source.

24
May

Five good reasons to not take drugs

The use of narcotic substances isn't usually a topic about which I have strong feelings. I don't take drugs myself, and I tend not to associate myself with people who do; but then again, I see no reason to stop other members of society from exercising their liberties, in the form of recreational drug use. I've never before spoken much about this subject.

However, one of my best friends recently died from a drug overdose. On account of that, I feel compelled to pen a short article, describing what I believe are some good reasons to choose to not take drugs.

26
Apr

Highway border crossings between Chile and Argentina

I've spent a fair bit of time, on several occasions, travelling in South America, including in Chile and Argentina. I've crossed the land border between these two countries several times, in several different places. It's an extremely long border, measuring 5,308km in total.

Recently, I was looking for a list of all the official crossings between the two countries. Finding such a list, in clear and authoritative form, proved more difficult than I expected. Hence, one thing led to another; and before I knew it, I'd embarked upon a serious research mission to develop such a list myself. So, here it is — a list of all highway border crossings between Chile and Argentina, that are open to the general public.

25
Mar

Travel is a luxury

International travel has become so commonplace nowadays, some people do it just for a long weekend. Others go for two-year backpacking marathons. And with good reason, too. Travelling has never been easier, it's never been cheaper, and it's never before been so accessible. I, for one, do not hesitate to take advantage of all this.

One other thing, though. It's also never been easier to inadvertently take it all for granted. To forget that just one generation ago, there were no budget intercontinental flights, no phrasebooks, no package tours, no visa-free agreements. And, of course, snail mail and telegrams were a far cry from our beloved modern Internet.

But that's not all. The global travel that many of us enjoy today, is only possible thanks to a dizzying combination of fortunate circumstances. And this tower (no less) of circumstances is far from stable. On the contrary: it's rocking to and fro like a pirate ship on crack. I know it's hard for us to comprehend, let alone be constantly aware of, but it wasn't like this all that long ago, and it simply cannot last like this much longer. We are currently living in a window of opportunity like none ever before. So, carpe diem — seize the day!

10
Feb

Solr, Jetty, and daemons: debugging jetty.sh

I recently added a Solr-powered search feature to this site (using django-haystack). Rather than go to the trouble (and server resources drain) of deploying Solr via Tomcat, I decided instead to deploy it via Jetty. There's a wiki page with detailed instructions for deploying Solr with Jetty, and the wiki page also includes a link to the jetty.sh startup script.

The instructions seem simple enough. However, I ran into some serious problems when trying to get the startup script to work. The standard java -jar start.jar was working fine for me. But after following the instructions to the letter, and after double-checking everything, a call to:

sudo /etc/init.d/jetty start

still resulted in my getting the (incredibly unhelpful) error message:

Starting Jetty: FAILED

My server is running Ubuntu Jaunty (9.04), and from my experience, the start-stop-daemon command in jetty.sh doesn't work on that platform. Let me know if you've experienced the same or similar issues on other *nix flavours or on other Ubuntu versions. Your mileage may vary.

31
Jan

Jimmy Page: site-wide Django page caching made simple

For some time, I've been using the per-site cache feature that comes included with Django. This site's caching needs are very modest: small personal site, updated infrequently, with two simple blog-like sections and a handful of static pages. Plus, it runs fast enough even without any caching. A simple "brute force" solution like Django's per-site cache is more than adequate.

However, I grew tired of the fact that whenever I published new content, nothing was invalidated in the cache. I began to develop a routine of first writing and publishing the content in the Django admin, and then SSHing in to my box and restarting memcached. Not a good regime! But then again, I also couldn't bring myself to make the effort of writing custom invalidation routines for my cached pages. Considering my modest needs, it just wasn't worth it. What I needed was a solution that takes the same "brute force" page caching approach that Django's per-site cache already provided for me, but that also includes a similarly "brute force" approach to invalidation. Enter Jimmy Page.

23
Jan

On and off

English is a language bursting with ambiguity and double meanings. But the words "on" and "off" would have to be two of the worst offenders. I was thinking about words that foreign-language speakers would surely find particularly hard to master, when learning to speak English. And I couldn't go past these two. From the most basic meaning of the words, which relates to position — e.g. "the book is on the table", and "the plane is off the ground" — "on" and "off" have been overloaded more thoroughly than an Indian freight train.

09
Jan

The Art of Sport

Soccer (or football) is the most popular sport in the world today; likewise, with over 700 million viewers, the 4-yearly FIFA World Cup is the most watched event in human history. Why is this so? Is it mere chance — a matter of circumstance — that soccer has so clearly and definitively wooed more devotees than any other sport? I think not. Team sports are an approximation of military battle. All such sports endeavour to foster the same strategies that can be used effectively in traditional warfare. Soccer, in my opinion, fosters those strategies better than any other sport; this is because, in tactical terms, it is the most pure sport in the modern world.