James Crisp – Page 16 – Software dev, tech, mind hacks and the occasional personal bit

I’ve been working on a rails app which has got quite a number of pages that share the same two css files and 3 javascript files. However, every time I visited any page of the app, all of javascripts and css files were being loaded from the server. Not good – site was very slow. Mucking around with ‘about:cache’ command in Firefox revealed that the css and javascript files had expiry dates set in the past – ie, no caching of them at all. Also, all the links to sylesheets and javascript files generated by rails had ?[some long number] after them. Some research on the web revealed that this is a new rails feature for caching – the long number is a timestamp for when the asset was last modified.

Okay, so why were these assets not being cached? A quick check with wget –save-headers revealed that the web server was sending a nocache directive to the browser. This seems to be the default setup for webrick and also for my shared apache hosting on railsplayground. Considering the new rails asset management system with the ?[last modified timestamp] in the URLs, nocache seems wrong. The browser should never expire the cache since rails will handle cache invalidation by updating the asset url with a new timestamp.

So, how can we implement no/very long cache expiry? In apache, you can use mod_expires or mod_headers to do this. My shared hosting does not support mod_expires, so I went for mod_headers in my .htaccess file.

Using mod_headers:

<FilesMatch "\.*$">
Header set Cache-Control "max-age=29030400"
</FilesMatch>

OR using mod_expires:

ExpiresActive On
ExpiresDefault "access plus 1 year"

Either of the the above will set up a cache expiry time of one year for all content (best you only do this for your rails app directories).

With a cache expiry time of one year in place, my rails apps run much much faster.

Naked Economics by Charles Wheelan

By James

On April 3, 2007

In Book Reviews, Finance, Technical

Just finished reading ‘Naked Economics: Undressing the dismal science’. It was a present from a friend, and I’ve been meaning to read it for a while. Glad I finally got around to it.

From the title, I assumed the book aimed to point out the failures of economics as a science. Not so at all – it was written by an economist and provides a high level overview of capitalism in layman’s terms.

Here’s some interesting questions and explanations from the book:

Why do we have money? So that we can indirectly swap our labour or goods for the things we want, even if the person with the things we want is not interested in our labour or goods. Without money, we would need to barter. That’s fine if you’re swapping chickens for rice. But what happens if you do web design, and you want meat for dinner, and the butcher does not want a website?
Money has value only because we all believe it does. We have faith that if we sell something (ie, convert it to the common value unit), we will then be able to swap that money for something we want.
Why have markets anyway? Markets produce what people want – ie, what people are willing to pay for (or at least what we are convinced into wanting through advertising etc).
Why not set the price of everything rather than letting it get worked out in a market? Well, it would be an enormous job, and things would not reflect the cost of production. Eg, bird flu wipes out half of the chickens in the world. There are now less chickens to go around so chicken becomes more expensive. People who really want chicken can still get it, but it costs them more. People who don’t care as much or can’t afford it eat fish or beef instead. If the cost of chicken was a constant mandated by the state, chicken distribution would need to be mandated in some other way. If there’s not enough chicken for everyone who wants it, who should get it? First come first served? Political clout? Personal connections?
Markets destroy. A new way to mechanize weaving may make thousands unemployed and destroy towns and communities. But according to Wheelan, the country as a whole is better off as we are able to produce more for less cost, hence increasing our standard of living. Ie, as a consumer, you may now be able to buy a shirt for half the price.
In politics, small motivated groups often drive policy. Eg, the general population does not care much one way or other on a subsidy on growing alfalfa. It might cost each person in Australia 0.01c per year. However, if the subsidy was to be removed, and the alfalfa farmers would care a lot. It may well mean their livelihoods so they would demonstrate, make campaign donations, vote as a block and generally make as much fuss as possible to make sure the subsidy was not removed.
Why do people work in sweatshops? According to Wheelan, the pay is generally better than for other jobs available – ie, sweatshops are not the cause of the problem, rather a symptom of the general poverty and lack of opportunity in the area.
Why is free trade good? So that everyone can do what they do best – ie, specialise to the max. The idea being that if everyone works on what they are most good at, then productivity overall is higher.
Why are tariffs bad? Because they support local industries that are not viable – ie, a poor uses of resources.
Why do we need governments? To provide the rails for capitalism. Eg, to enforce laws (so you can’t just kill me and take my stuff), to regulate the excesses of the free market and to provide goods and services that people need but that free markets will never provide. Also, to do things that individuals cannot do alone, but are in the interest of the population as a whole – eg, build infrastructure.
Care for the environment is a luxury good – ie, if you and your family are starving, cutting down trees to sell for food seems like a pretty good idea.
Companies destroy the environment because the current monetary cost of environmental destruction is usually minimal. If the full cost of environmental destruction was factored into the market (eg, companies have to pay for pollution and destruction), then environmental destruction would slow dramatically.
Who can create new money? The reserve bank, and it does it by buying bonds from banks with money that did not previously exist.
How can the reserve bank change interest rates? It can sell government bonds at its target rate and it can buy bonds (with brand new money) or sell bonds from/to trading banks to influence the amount of cash the banks have to lend. Eg, lots of cash at a trading bank means they’ll lower the interest rates so as to rent out the money.
How come the economy can go into recession for no real reason? If people are worried, they don’t spend. If people don’t spend, then companies can’t afford new/current investment. People get sacked and then can spend even less. People get more worried and the cycle continues.
Why is the level of savings in a country important? Money in the bank means it can be lent out to people who want to use it to create new businesses or expand current businesses. Access to capital allows growth.

I wouldn’t take these on face value, and I would certainly question some of the assumptions on which they are based. However, they provide some interesting areas for further thought.

Mango Liqueur – Fruition

By James

On March 31, 2007

In Brewing, Personal

The mango liqueur started about a month ago has now reached fruition. After filtering with cheese cloth, and adding a little sugar (much less than a cup), it is quite tasty. It should improve further as it ages over the next month or so, assuming it lasts that long 🙂

Starting at ThoughtWorks: First Five Weeks

By James

On March 26, 2007

In Ruby / Rails, Technical, ThoughtWorks

Well, I’ve been with ThoughtWorks for just over 5 weeks now, and I thought I’d write down some thoughts before the hiring and joining process got lost in the misty swamp of my memory.

Hiring process
To cut a long story short, I did a phone screen with HR, a coding test and then some fairly quick aptitude and personality tests and finally 3 interviews. You have something like a week to do the coding test and then submit your code for review. I had the other tests and interviews on a single day. Although this sounds pretty horrendous, it actually wasn’t too bad. Tests were pretty quick and the interviewers were astoundingly friendly. I finished by something like 3pm in the afternoon, including a lunch break, and surprisingly didn’t feel too bad or stressed afterwards.

Induction
As a fairly impressive start, I had 2 days of induction in Melbourne (I live in Sydney). ThoughtWorks arranged drivers, hotel and flight so it was all very smooth. This was lucky as I was pretty jet lagged and confused – I’d just flown back from an overseas holiday not long before. Induction was largely getting a company provided laptop, meeting people and getting an introduction to various internal systems and procedures. As an aside, I’ve heard that there is now an “immersion” process where you get sent to India for a week or two for induction but can’t comment on that.

A few weeks on the beach
When you’re not assigned to a client project, you are “on the beach”. This means you go into your local office with your laptop. It’s really great – there’s no particular tasks assigned to you, but the opportunity is there to get involved in a lot of interesting stuff. To give you some examples, here’s some of the stuff I’ve had the chance to do:

Write an open source plug-in for Mephisto for ThoughtWorks Studios
Be involved in scoping out and estimating for a RFI from a new client
Pair with another developer to do code reviews of potential new recruits
Help out briefly with a fun project to develop a driver for a USB build light for continuous integration servers (red for broken build, green for good build, etc)
Help out on client projects – I was asked to whip up a little proof of concept for JRuby and Java integration and learnt a bit getting this set up
Do a little bit of Google Maps integration
Meet colleagues and learn more about procedures etc
Get invited to lunch with the managing director – this is something that happens for all new hires and I think it’s really great
Almost go out on a pre-sales call (I’ve got to go back to Melbourne and will miss this unfortunately)
Catch up on tech reading such as blogs, books etc
Go to a swanky talk given by Martin Fowler and Kristan Vingrys
Eat lots of free lunches (usually twice a week) and attend various talks at the office given by other consultants
Drink lots of free coffee (ThoughtWorks has a coffee tab with a local cafe)

First project
Much fun as it is on the beach, after a few weeks, I was itching to join the big boys and go on a project. Getting assigned to a project is the purview of your professional services manager, and can be pretty changeable. The saying is that “you don’t really know what project you’re on till you walk in the door of the client site” and I’ve even heard “you don’t really know what project you’re on till you’re on the plane home”. There’s a grain of truth in these – it can look like you are going to go on a project and then it doesn’t come through, or some other project becomes more important or whatever. I almost went on several different projects before finally ending up on quite a cool Ruby / Rails project with a startup in Melbourne. So, I got to join the jet set and have been flying down to Melbourne during the week, and back for the weekends. This is a bit tiring, but ThoughtWorks does its best to make things comfortable. I’m staying in a really nice corporate apartment in Melbourne, flights are arranged and paid for and drivers are scheduled for pickup and drop off to the airport. There’s also a generous per diem allowance for food. The project is really cool, and I’m enjoying it, but can’t say more as it is under a NDA.

Back on the beach.. but only for two days!
My first project was two weeks, so after that I returned to the beach. Today is my second day on the beach. However, it turns out that the client was very happy with our first two weeks work and they’ve invited us back again until Easter. This means I need to fly back to Melbourne tomorrow. This won’t continue indefinitely though – when I was discussing the project with my professional services manager, we agreed that I would not need to stay on a Melbourne project for more than 6 weeks. And clearly this is in ThoughtWorks interest as well – it costs a lot more to fly somebody in from Sydney every week and provide accommodation etc. I’m going to be transitioning off the project by Easter and a Melbourne based consultant is going to take over from me if the project continues further. It’ll be good to be on a Sydney based project again but I feel it would be unfair not to say that ThoughtWorks has done a really good job in making working in another city as convenient and pleasant as possible.

Various benefits
ThoughtWorks is pretty generous in the expenses department. They cover your mobile phone, home internet, per diem when away, give an allowance for training courses and books, etc. There’s also lots of free lunches, food, coffee and catered events.

Transparency and knowing what’s going on
I’ve been quite impressed to get a monthly update email that talks about ThoughtWorks plans, goals and financials, headcount etc in significant detail. There’s also various update meeting where you get to hear how projects are going and what’s happening with various clients. Personally I’m really glad to see this type of thing, as at previous jobs, this has been privileged information, and most of the time, I have not really had any idea how well the company is doing financially as a whole, or what the future plans and directions are.

Variety and Unpredictability
These are really two faces of the same coin, and depending on your character and experience, I think you might either love or hate this. You really don’t know what project you’re going to be working on, what your role will be, what industry the client is in, what type of development they need or for what platform or in what language. In fact, you don’t even know what city you’re going to be in during a given week. I’m enjoying this at this point as my last job was always in the same office, with the same technologies etc. However, I can see it may be trying in the long term, and it does make it difficult to do the shopping or organise things with friends during the week. On the other hand, I have heard that most of the work in Sydney is for big companies like banks and telcos in the city CBD within walking distance to the office, and the majority in Java. So perhaps my short experience so far is not the norm.

In conclusion…
So far, I can honestly say that it’s been really great working at ThoughtWorks. I’ve had a chance to do some of the stuff I’ve wanted to do for ages like work on a bit of open source and do some commercial Ruby on Rails work. My colleagues have been friendly and welcoming, and I’ve been wowed by the level of care that ThoughtWorks takes of its employees.

A few choice quotes from “The Unbearable Lightness Of Being” by Milan Kundera

By James

On March 26, 2007

In Book Reviews, Fiction, Personal

Starts slowly with quite a philosophical bent, but becomes really compelling once the main characters are introduced. Some memorable quotes:

Happiness
“If Kerenin had been a person instead of a dog, he would surely have long since said to Tereza, ‘Look, I’m sick and tired of carrying that roll in my mouth every day. Can’t you come up with something different?’ And therein lies the whole of man’s plight. Human time does not turn in a circle; it runs ahead in a straight line. That is why man cannot be happy: happiness is the longing for repetition.”

Love
“The brain appears to possess a special area which we might call poetic memory and which records everything that charms or touches us, that makes our lives beautiful… Their love story did not begin until afterwards: she fell ill and he was unable to send her home as he had the others. Kneeling by her as she lay sleeping in his bed, he realized that someone had sent her downstream in a bulrush basket. I have said before that metaphors are dangerous. Love begins with a metaphor. Which is to say, love begins at the point when a woman enters her first word into our poetic memory.”

A feeling of importance
“We all need somebody to look at us. We can be divided into four categories according to the kind of look we wish to live under. The first category longs for the look of an infinite number of anonymous eyes, in other words, for the look of the public…
The second category is made up of people who have a vital need to be looked at by many known eyes. They are the tireless hosts of cocktail parties and dinners…
Then there is the third category, the category of people who need to be constantly before the eyes of the person they love. Their situation is as dangerous as the situation of people in the first category. One day the eyes of their beloved will close, and the room will go dark..
And finally there is the fourth category, the rarest, the category of people who live in the imaginary eyes of those who are not present. They are the dreamers.”

Kitsch
“Kitsch is the absolute denial of shit, in both the literal and the figurative senses of the word; kitsch excludes everything from its purview which is essentially unacceptable in human existence…
Kitsch causes two tears to flow in quick succession. The first tear says: How nice to see children running on the grass! The second tear says: How nice to be moved, together with all mankind, by children running on the grass! It is the second tear that makes kitsch kitsch. The brotherhood of man on earth will be possible only on a basis of kitsch…
And no one knows this better than politicians. Whenever a camera is in the offing, they immediately run to the nearest child, lift it into the air, kiss it on the cheek. Kitsch is the aesthetic ideal of all politicians and all political parties and movements…
In the realm of totalitarian kitsch, all answers are given in advance and preclude any questions. It follows, then that the true opponent of totalitarian kitsch is the person who asks questions…
From that time on, she [Sabina] began to insert mystifications into her biography, and by the time she got to America she even managed to hide the fact that she was Czech. It was all merely a desperate attempt to escape the kitsch that people wanted to make of her life.”

Contact / Feedback Form Plugin for Mephisto

By James

On March 19, 2007

In Mephisto, Ruby / Rails, Technical, ThoughtWorks

Introduction
If you use Mephisto, a content management / blogging system written in Rails, you may well be interested in using this new plug-in. It provides a form that lets visitors to your site leave their contact details and send you messages or feedback via email.

UPDATE
Please check out information about using the contact form plugin with Mephisto Drax 0.8.

License
This plug-in was developed for the new ThoughtWorks Studios site. As I wrote it at and for work, it is copyright ThoughtWorks, 2007. However, ThoughtWorks, being generous souls, is happy for me to open source it under the Apache 2.0 licence, which pretty much means you have free reign to use it as you want.

Requirements

Mephisto Edge (the latest stable 0.7.3 release does not have support for Mephisto plugins)
Rails Edge (required by Mephisto edge)
ActionMailer (comes with Rails) correctly configured with SMTP server etc, so that emails can be delivered. See “Configuration” section here for more details.

Installation

ruby script/plugin install http://github.com/jcrisp/mephisto_contact_form/tree/master

or in your vendor/plugins directory for Mephisto:

git clone http://github.com/jcrisp/mephisto_contact_form/tree/master mephisto_contact_form

Make sure you restart your web server at this point so that the plugin is loaded.

Setup
1. Create a new template called ‘contact_us.liquid’ though the admin web interface (under the ‘Design’ tab).
Paste in the following code:

<H1>Contact Us</H1>
{% contactform %}
<p>{{ form.name }}<label for="author"><small>Your name</small></label></p>
<p>{{ form.email }}<label for="email"><small>Email address</small></label></p>
<p>{{ form.phone}}<label for="phone"><small>Phone number (optional)</small></label></p>
<p>{{ form.subject}}<label for="subject"><small>Subject</small></label></p>
<p>{{ form.body }}</p>
<p>{{ form.submit }}</p>
{% endcontactform %}

Feel free to modify labels, layout etc.

2. Edit

{MEPHISTO_ROOT}/vendor/plugins/mephisto_contact_form/lib/contact_notifier.rb

and put in the email address you want contact form submissions to go to.

3. Link to “/contact_form” from your site.

Any issues / questions / suggestions?
Best to post comments on this blog.

Technical Info
The contact form plugin is actually a combination of a rails plugin, a liquid block plugin and a Mephisto plugin. See this post about developing Mephisto plugins for more information.

Wing Chun: Bong Sau Tips

By James

On March 8, 2007

In Personal, Wing Chun

Today my class was visited a very talented high level instructor. Although he only spent a few minutes looking at my bong sau, he gave two invaluable tips:

When bringing your hand and arm up into bong sau, you need to be moving both upwards, forwards and inwards towards the centre simultaneously. A good way to do this is to imagine your elbow tracing an arc through the air from start to end point.
When moving from bong sau to tan sau when rolling, move into fook sau first, and then roll your wrist over. This will stop your hand from dropping and will leave your hand on the centre line.

The Secrets of Consulting by Gerald Weinberg

By James

On March 5, 2007

In Book Reviews, Soft Skills and Mind Hacks, Technical

The Secrets of Consulting by Gerald Weinberg is one of the most entertaining (largely?) non-fiction books that I have read – a heady mix of How to Win Friends and Influence People, Fear and Loathing in Las Vegas (just look at the illustrations!) , and the 10 Commandments. The book provides general advice, case studies/stories and then derives general “rules” and recommendations from these.

Personally, I found the chapter on the pricing of consulting to be particularly interesting. Thinking about setting a price previously, I would have suggested it should be enough to cover costs and make a bit of a profit. Weinberg points out that price is more than this – it is a big factor in the relationship and the level of respect for the consultant.

The Weinberg’s consulting “rules” are quite numerous – my personal favourites are:

“If you can’t fix it, feature it.”
“It may look like a crisis, but it’s only the end of an illusion.”
“You’ll never accomplish anything if you care who gets the credit.”
“If something’s faked, it must need fixing.”
“The name of the thing [label] is not the thing.”
“It tastes better when you add your own egg.”
“You don’t get nothin‘ for nothin‘. Moving in one direction incurs a cost in the other.”
“Whatever the client is doing, advice something else.”
“What you don’t know may not hurt you, but what you don’t remember always does.”
“Clients always know how to solve their problems and always tell the solution in the first five minutes.”
“When change is inevitable, we struggle most to keep what we value most.”
“The biggest and longest lasting changes usually originate in attempts to preserve the very thing ultimately changes most.”
“Effective problem-solvers may have many problems, but rarely have a single, dominant problem.”
“Make sure they pay you enough so they’ll do what you say. The most important act in consulting is setting the right fee.”
“The more they pay you, the more they love you. The less they pay you, the less they respect you.”
“Spend at least one day a week getting exposure.” and “Spend at least 1/4 of your time doing nothing.” and make sure your fee covers this.
“Set a price so you won’t regret it either way.”
“If they don’t like your work, don’t take their money.”
“Cucumbers get more pickled than brine gets cucumbered.”
“Give away your best ideas.”
“Look for what you like in the present situation and comment on it.”
“Study for understanding, not for criticism.”
“Never promise more than 10% improvement.. if you happen to achieve more than 10% improvement, make sure it isn’t noticed.”
“Consultants tend to be the most effective on the third problem you give them.”
“The child who receives a hammer for Christmas will discover that everything needs pounding.”

Mango Liqueur

By James

On March 4, 2007

In Brewing, Food and Drink

Started a quick mango liqueur this evening. Two large fresh mangoes worth of pulp (approx 500ml) mixed with 500ml of vodka in a jar. Planning to shake every few days for the next few weeks, filter and then add about 1 cup of sugar, before maturing for a few months. I have high hopes, as a similar recipe worked well with bananas in the past.

_vimrc for Ruby

By James

On March 1, 2007

In Ruby / Rails, Technical

In the past I’ve used gvim for Ruby coding. It’s been pretty good, especially with the new tabbed editing and omni complete (bit like intellisense in Visual Studio) introduced in vim 7. However, when I downloaded vim at work, I was missing the secret sauce – a good vimrc. Here’s my usual vimrc for ruby:

set nocompatible
behave xtermset
selectmode=mouse
set nu
set tabstop=2
set shiftwidth=2
set softtabstop=2
set ai
set columns=100
set lines=70
set guifont=Courier:h10
set expandtab
set smarttab
let g:rubycomplete_rails = 1

Among other things, it makes the default window size bigger, uses a prettier font, sets up auto indenting ruby style, and turns on omni-complete.

By the way, on windows, assuming a default install, vimrc is to be found here:

C:\\Program Files\\Vim\\_vimrc