July 2013 – scrambled tofu

Testing sites with beforeunload and Lettuce/Cucumber

I recently added a beforeunload event handler to a site I’m working on, which instantly caused a regression of the entire Lettuce test suite before they got stuck on a “Leave this page?” dialog. We reuse the same Selenium browser session between tests in order to make our tests run in something approximating less than a decade.

Unfortunately Ghostdriver can’t see alerts and dialogs, which makes simply dismissing the dialog in Selenium kind of hard, but an easier way is at the end of the scenario to simply disable the event, and let it be reinstated with the next page load.

Add this hook to your Lettuce steps:

@after.each_scenario
def disable_beforeunload(scenario):
    """
    Disable before unload after a scenario so that the next scenario can
    reload the site.
    """

    world.browser.execute_script("""
try {
    $(window).off('beforeunload');
} catch (e) {
}
    """)

vim + pathogen + git submodules

As part of PyCon Au this weekend I did a lot of hacking on my laptop, which is not something I’ve done for a while, given how much I used to hack on my laptop. I was frequently getting annoyed at how my vim config wasn’t the same as it’s currently on my work desktop.

Back in uni, I used to keep my dotfiles in revision control on a machine I could connect to. All I needed was my ssh agent and I could get all my config.

Recently, when wanting to extend my vim config, people’s pages tell me to do it through vim pathogen, which I didn’t have set up.

Also there have been times when people have asked for my vim setup, which I wasn’t easily able to provide.

Given all of that, I decided it was time to rebuild my config using pathogen + git submodules from the ground up. As part of this, I updated quite a few plugins, and started using a few new things I hadn’t had available without pathogen, so it’s still a bit of a work in progress, but it’s here.

Installing new plugins is easy with git submodule add PATH bundle/MODULE_NAME.

If you’re a vim user, I strongly recommend this approach.

free as in gorgeous

I’m at PyCon Au. ((Thanks to Infoxchange, who sent me, and are also sponsoring the conference.)) I made it this year. There were no unexpected collisions in the week leading up to it.

I decided at the last moment to do a lightning talk on a piece of Django-tech I put together at Infoxchange, a thing called Crisper, which I use in a very form-heavy app I’m developing. Crisper is going to be up on Github, just as soon as I have time to extract it from the codebase it’s part of (which mostly consists of working out where it’s pointlessly coupled).

The title of my post relates to deciding to do this talk, and the amazing free and open graphic design assets I have available at my fingertips to create an instant title slide. 5 minutes in Inkscape, using the Tango palette and Junction (available in Fedora as tlomt-junction-fonts) and Inkscape to put together things like this:

Anyway so some pretty good content today at DjangoCon Au. I especially enjoyed the food for thought about whether we should be targeting new development at Python 3. It has struck me that writing greenfields code on Python 2 is a dead end that will eventually result in my having to port it anyway. Thinking I will conduct a quick stocktake of the dependencies we’re using at work to evaluate a Python 3 port. I think generally we’re writing pretty compatible code using modern Python syntax, so from the point of view of our apps, at port at this stage would be fairly straightforward.

Some interesting discussion too on the future of frameworks like Django. Is the future microframeworks + rich JS on the frontend using Angular or Ember. How do things like Django adapt to that? Even though JS has nothing on Python, is the future node.js on the back and somethingJS on the front? ((It always cracked me up that my previous web-app was this HTML5-y app, but designed without the use of frameworks. Old and new both at once.))

This is actually a nice aside that I’ve been working on a pure in-web app for visualising data from Redmine using D3.js and Redmine’s RESTful API. ((https://github.com/danni/redmine-viz)) Intending to add configuration in localstorage (probably via Angular) once I have the visualisations looking good. It both serves a practical purpose and an interesting experiment on writing web apps without a web server.

Almost back on topic, I had dinner with a bunch of cyclists tonight, and got to talking about my crowd-sourced cycle maps project, ((https://github.com/danni/cycle-router)) which hasn’t gone anywhere because I still don’t have any hosting for it. I should try having dinner with cyclists who work for PaaS hosting providers. ((I need PostGres 9.2 and PostGIS 2.0. Come chat to me!))

Finally, I’m trying to recruit talented web developers who have a love of Agile, test driven design and Python. Also a technical tester. Come and talk to me.