@order_item = OrderItem.new(:hi => "hem", :ho => "hum")
@order_item.save!

@order_item = order.order_items.create(:hi => "hem", :ho => "hum")

@order_item = OrderItem.some_custom_creation_method(:hi => "hem", :ho => "hum")

The Problem

When you’re writing your spec (up front, of course!), you don’t want to presume too much about how the implementation will unfold. So, do you stub the create method on the model class? But what if we implement using the new/save combo (as above)? Or, what if we create the model instance through an association?

My Solution

My first pass solution to this problem is the following, based on Matthew Heidemann’s association stubbing technique:

module Spec
  module Mocks
    module Methods
      def stub_creators!(association_name, klass, stubs = {}, valid = true)
        target_mock = Spec::Mocks::Mock.new(klass, {:save => valid, :valid? => valid}.merge!(stubs))
        target_mock.stub!(:save!).and_return do
          target_mock.save
          valid || raise(ActiveRecord::RecordNotSaved)
        end
        klass.stub!(:new).and_return(target_mock)
        klass.stub!(:create).and_return do
          target_mock.save
          target_mock
        end
        klass.stub!(:create!).and_return do
          target_mock.save!
          target_mock
        end
        mock_association = Spec::Mocks::Mock.new(association_name.to_s)
        mock_association.stub!(:create).and_return do
          target_mock.save
          target_mock
        end
        mock_association.stub!(:create!).and_return do
          target_mock.save!
          target_mock
        end
        mock_association.stub!(:build).and_return(target_mock)
        self.stub!(association_name).and_return(mock_association)
        target_mock
      end
    end
  end
end

What this is doing

The thinking here is that, when I write my spec, I don’t want to be concerned with whether the implementation takes the create, new/save, build/save, or other route. In my spec I just want to know that at some point the controller asked for a model instance to be created and saved. The above code, which I put in spec_helper.rb, allows my specs to do just that. Essentially, I stub save so that it returns true or false, depending upon the optional valid parameter, and the other creation stubs derive from that: save!, create, create! on the target association class and the association itself. I also stub out new and build for convenience. This code ensures that save is always called, even though we’ve stubbed out create etc. Now if I need to check that a controller action has caused a model instance to be created, I need only ever check that save is called.

An example

In my specs I call stub_creators! on an instance of the association owner (in our example, the association owner is Order), passing it the name of the association I want to stub (order_items), the model class of the association target (OrderItem), optional stubs for instances of the association target, and whether or not we want the returned model instance to be valid (defaults to true). With this in place, I can do this:

describe OrdersController do
  before(:each)
    @current_user = mock_model(User, :login => "me", :logged_in? => true)
    @order = @current_user.stub_creators!(:order_items, Order)
  end

  it "should create a new order_item" do
    @order.should_receive(:save).and_return(true)
    post 'create'
  end
end

And it doesn’t matter which route the implementation takes to create that model instance. As long as save is called at some point, I know the controller has triggered the creation of the instance somehow.

Thoughts

Now, while this seems to work for me, I don’t really know whether this is kosher. Is it a sensible approach to take? I haven’t tested this extensively; as I said, it’s a first pass. Also, there’s bound to be stuff missing from my solution (for example, it doesn’t handle find_or_create_by_). Can a similar approach be taken to the various ways to delete an object, too? I shall continue to experiment.

Anyway, here’s how I got nokogiri to install under Snow Leopard without resorting to macports or fink:

sudo gem install nokogiri -- --with-xml2-include=/usr/include/libxml2 --with-xml2-lib=/usr/lib --with-xslt-dir=/usr

What’s weird is that, unless I’m mistaken, those paths are exactly where nokogiri should be looking for the relevant libxml2 files in the first place! I’m still to find out whether it all works as it’s supposed to. But installation is the first step! Let me know if it works for you.

However, there was one thing I couldn’t figure out how to do: booking a shared resource, such as a meeting room or a car park. Today, we figured out how to do it, and, in hindsight, it should have been obvious.

To book a shared resource, create a calendar event in iCal as you normally would, making sure the event is created in your Exchange calendar as opposed to your personal (local) one. Then, in the invitees field, add the resource you wish to book. Start typing the name of the resource, and if your Exchange integration is working correctly (and your IT people have set up the resources in Exchange correctly), it should find the resource just as if you were adding a person as an invitee. Once you’ve added the resource, you should see a link that says “Available meeting times…”. Click it. This will show you when the resource is available and when it’s booked, as well as the availability of any other people you’ve added to the invitees field. Once you’ve done that, you’re good to go! Microsoft Outlook users will see that the resource has been booked (if they’ve added the resource as a Shared Calendar to their Outlook console).

The Landing Pilot is the Non-Handling Pilot until the “decision altitude” call, when the Handling Non-Landing Pilot hands the handling to the Non-Handling Landing Pilot, unless the latter calls “go-around”, in which case the Handling Non-Landing Pilot, continues Handling and the Non-Handling Landing Pilot continues non-handling until the next call of “land” or “go-around”, as appropriate.

In view of the recent confusion over these rules, it was deemed necessary to restate them clearly.

– British Airways memorandum, quoted in Pilot Magazine, December 1996 (and in The Pragmatic Programmer, which is where I read it).

Note that we’re experiencing a few difficulties with our Citemine production server environment, which means slow page loads from time to time. And it’s clearly lacking polish, but hopefully it serves its purpose as a proof-of-concept so that you can get a feel for what it’s all about. But please do read the paper. I’ve been told it’s a fun read.

One thing from that story that caught my attention was this:

She (Rachel Nolan) said people living near train lines or stations would not be able to tap into the free internet service because it would be “firewalled”.

That would have to be one pretty intelligent firewall! Here are some actual possibilities to guard against free-loaders. One not so attractive way to do it would be to set a limit on daily downloads. The theory is that there’s only so much you could download on the longest possible trip on the QR network in south-east Queensland (say, Gold Coast to Nambour, or something like that). The other more attractive solution, in my opinion, would be to tie usage to go cards. Your internet session starts when you swipe on at the beginning of your journey, and it finishes when you swipe off. There’d be some kind of web-based login procedure like you get at hotels and elsewhere, where you enter your go card number to gain access; or regular users could have the option of registering the MAC address of their wireless card with QR/Translink to skip the login procedure. Given that it still takes ages for a credit card top up to find its way onto my go card, I don’t hold out much hope for QR/Translink being able to implement this particular solution within the already very optimistic time frame of early 2010. But I do think it’s a reasonable long term solution. It might even help Translink in their quest to move more commuters over to the go card from paper tickets.

So what does this mean? It means that right now Twitter is hot. People are talking about it, and that’s the best that Biz Stone and company could hope for. The big question for Twitter is how to convert all the talk into more users, and ultimately revenue. If they do manage to do this, it would be nice to know how they did it!

Heard this song on the radio a while ago and couldn’t track it down. But today I caught it on ABC Local Radio, would you believe.

National benefit versus private benefit… Hey, that’s what capitalism is designed to do, is to guarantee that there is no contradiction.

The line got a delayed laugh, because it took the audience a few moments to realise that was all Professor Ullman had to say on the topic, and that he’d moved on to the next topic. People laughed, but he was serious, and more right than many would be willing to accept.

Fair Trade is really a movement consisting of a number of principal organisations: Fairtrade Labelling Organizations International (FLO), World Fair Trade Organization, Network of European Worldshops and European Fair Trade Association. While Fair Trade refers to the overall movement, Fairtrade refers to the certification given by FLO. In the rest of this article, I refer to Fairtrade, because when you’re in the supermarket shopping for coffee, that’s the label you will see. One of the defining features of Fairtrade is that it guarantees the coffee grower (or whatever the product happens to be; we’ll just be dealing with coffee in this article) a predetermined minimum price for his/her coffee.

You can look at Fairtrade as being just like free trade, except that the coffee being sold has been sprinkled with a range of “socially responsible enhancements”. As mentioned, chief among these enhancements is the knowledge that the farmer who grows the coffee beans that end up in your mug gets at least an agreed minimum price for the coffee, and his/her farm workers are similarly guaranteed a minimum wage. The idea is that the consumer is paying a premium for a superior product, because the coffee has been produced in a way that yields greater benefits for the farmers who grow the coffee. So, in this respect, the price of Fairtrade coffee is set by supply and demand, just like non Fairtrade coffee. There is an ethical dilemma here, however. An important criticism of Fairtrade, and one that I believe is completely valid, is that Fairtrade artificially inflates the price of coffee, encouraging more people to grow coffee, thereby increasing supply and, in the long run, placing downward pressure on coffee prices (non-Fairtrade coffee). This, of course, results in farmers receiving less and less for the coffee they grow. The ethical dilemma is that Fairtrade coffee is marketed as being socially responsible and fair, but the question must be asked “fair to whom?” Certainly not to the farmer who sees the price of his coffee going down because all his mates have decided to try to get a piece of the action. The already oversupplied coffee market becomes even further oversupplied. Consumers with a social conscience, I believe, ought to think twice about Fairtrade – it might not be as fair or as socially responsible as you think. Besides, I wonder just how many consumers of Fairtrade coffee take the time to find out what this minimum wage is, and what this minimum wage could buy in the given farmer’s country.

Rainforest Alliance has different goals to that of Fairtrade. Its mission is to

…conserve biodiversity and ensure sustainable livelihoods by transforming land-use practices, business practices and consumer behavior.

Rainforest Alliance certification means that goods (coffee in our case) are produced in an environmentally sustainable fashion, in adherence to the Sustainable Agriculture Network standards. These standards set down criteria relating to water pollution, erosion, environmental and human health, wildlife habitat protection, waste, water efficiency, farm management and working conditions. An important distinction from Fairtrade is that there is no artificial minimum price set for the product. As such, there is no artificial incentive introduced for more farmers to produce coffee, and therefore no distortion of production levels and prices. For these reasons, I’d be more comfortable buying Rainforest Alliance Certified coffee than Fairtrade Certified coffee. Rainforest Alliance certification is gaining momentum, with some big corporations, no doubt trying to improve their image, serving up or packaging up Rainforest Alliance Certified coffee. These include McDonald’s and Kraft.

Of course, there are other kinds of certification as well, including UTZ and various organic certifications. There’s also direct trade, whereby a coffee roaster or boutique coffee shop establishes a relationship directly with a coffee grower. This allows the buyer to select a grower who meets their own set of ethical criteria. Because the buyer knows first hand how the coffee is produced, there is no formal certification required. See the Cooperative Coffees site for a good explanation of the most common kinds of certifications.

Meanwhile, back at the Kuranda Coffee Republic, Mike just serves cups of great coffee, which are each works of art and feats of engineering, with an ample helping of banter. His differentiation is that he sells only direct to people, spurning lucrative approaches by corporations. I guess you could call this extreme direct trade, so his coffee requires no further certification. It’s not about capitalism or not capitalism, he claims. It’s that he wants all of the beans he grows to be served with a “Hello, how’s it going” and a “Thanks for coming.” Sell to corporations, he argues, and you can’t be guaranteed that the shop assistant or barista will respect the beans and the experience. And here’s a tip: engage Mike in good conversation, say thanks for your coffee, and for your next cup he might just give you the discount he reserves for locals. Even at the standard price of $3 for a large cup, you’ll be hard pressed to find a better value coffee anywhere in Far North Queensland, or all of Queensland for that matter. Will I be going back to the Kuranda Coffee Republic next time I’m in Cairns? You bet.

We’re going to get the chance to see their new house for ourselves when we visit them in the near future. It will be Xander’s first flight. If it’s anything like his first train trip, he’ll have a ball. Just hope we can avoid the Dengue fever epidemic when we get there.

In my last article, I mentioned a little cafe in Mount Glorious called the Elm Haus. Well yesterday Karen and I made a special trip up the mountain to try their Devonshire tea, having left Xander with his grandparents. We’re delighted to say that it was well worth it.

This armour is just one of the many curiosities on display at the Elm Haus

The Devonshire tea

There's nothing like a good Devonshire tea

It was a wet, overcast day. But it made for a great drive up to Mount Glorious, which was shrouded in clouds. The atmosphere created by the fog as we drove through the rainforest was worth the trip alone. The Elm Haus Cafe was very inviting to the sodden traveller, and provided us with a homely lunchtime meal. We plan to revisit for Devonshire Tea sometime.

The ReCaptcha guys need to invent an algorithm that gives an estimate of the likelihood that a human could actually decipher a word, and then only present those above a certain threshold. That’s a different problem to the one of having a machine actually decipher the text, and I reckon it’s probably an easier one. The ReCaptcha above is just plain silly.

Another thing I’ve done is fully widgetize my blog. So everything that used to be hand-coded into the various PHP files that make up my theme is now a widget (Twitter feed, Google Analytics and so on). This makes everything much easier to maintain, and change, if I feel like it.

In related news, AJ has made the switch to WordPress from Blosxom. I’m pretty sure he won’t look back. I’ve been using WordPress since mid-2005, and I reckon WordPress is getting better with every release (2.7 in particular is a pretty big step in the right direction, IMHO). It’s very well supported, has a large user community, and it just works. Fantastic.

Update 29 Dec, 2008: I’m now using a variant of Chris Harrison’s threaded comment styling. He’s written a tutorial on how to style your comments.

I’ve previously documented my thinking on issues of surveillance, though I hadn’t specifically considered the situation where a member of the public films a police operation or an operation conducted by some other state agency. I think what I wrote in that article holds for this case, too. If anything, I’d expressly encourage this sort of surveillance. We still live in a free democracy, don’t we?

Herman’s Hermits – No milk today

(AAP)

Will keep you posted as things evolve further. But just to give you an idea, we’ve already iterated through several “alpha” versions and expect to have a public beta ready by the end of February. Stay tuned for an explanation of what the service actually does.

I certainly had a laugh, but one does have to wonder whether the Liberals might have found a better use of their limited funds…

Nah!

Yet, for all that, his election in and of itself has given hope to millions of his fellow countrymen and women, and perhaps billions of people around the world who happen to share his skin colour. One gets the feeling that it is the kind of hope accompanied by equal parts relief and outright joy, particularly for those who have lived long enough to witness some of the various events in US history that each contributed to the moment of Barack Obama’s victory speech. What’s sad is that it has taken so long for this day to come. What’s sad is that the colour of someone’s skin still matters. History, too, is sure to remember him primarily as America’s first black president, regardless of what he achieves or fails to achieve over the next four or eight years.

Whether you agree with his politics or not (or, if like me, you feel there was so little depth to the presidential campaigns of both the major parties that it is nearly impossible to tell what policies will be pursued), you must admire Obama’s terrific achievement. To overcome McCain and Palin so definitively is an enormous feat; but to have first defeated the machine called Hillary and Bill Clinton is, when you think about it, incredible.

Living in a small country across the Pacific Ocean as I do, with any luck I will not be chastised for confessing that, perhaps more than anything, I look forward to being wowed by Barack Obama’s indisputably sublime oratory skills. A president with a command of the English language: how novel. Our very own prime minister might take a leaf out of the President-elect’s book, and infuse some inspiring words into his rather mundane speeches.

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Updated especially for Clinton:

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 Unported

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I would be more than grateful if you could point your friends and colleagues at this blog entry, particularly if they are involved in writing research manuscripts.

Thank you!

Often we seem to use the term Ubiquitous Computing to mean “computers everywhere” as if just having the hardware all over the place was a worthwhile end in itself.

But maybe a better meaning is “computing available when you want it in a way that makes sense for where you are and what you’re doing” which is much harder to do than “computers everywhere”.