Elf Sternberg

If you work with Django for any period of time, the day comes when you’ll be accepting outside data from your users: files, images, and the like.  Django provides only two places where you can store these items: in memory, or to a file.  Django storages provides for two more critical locations: BLOBs in your SQL database (which you may want to do– never know), and most importantly, Amazon AWS S3.  For my current work with a film library and catalog, having S3 be the storage solution has always been a bit of a kludge: producers would upload films to the server, and we’ve eventually get it into S3.  Now, with AWS S3, Django Storages backed with the incredible BOTO library makes the entire process unbelievably easy.

Storages also supports storing content in the database, CouchDB, FTP, or anything else you can imagine. And the source code makes for excellent examples.

Also, if you use django-storages, consider looking at many of the branches on bitbucket, because there are variants of it for S3 that disable the HTTPS default for Cloudfront, which was important for us at Indieflix. Not everything coming out of Cloudfront has to run through SSL.

I resolved, earlier this year, to start finishing some of my projects.  That hasn’t gone too well– the day jobbe appears to have chewed up most of my time.  But after my Palm V died, I no longer had a chiming program to help me get into the rhythm of the day.  I’ve since replaced it on my Palm T|X, but I’ve wanted something that I could feed through my headphones, rather than rely on the Palm, which chimes loud enough the whole house or office can hear it.

So, my first foray into times and chimes is done.  I used some free bamboo photoshop brushes, and jQuery, but the HTML, CSS, graphics, layout and so forth is all mine.  The script is 100% HTML5, there’s a lot of CSS3, and it uses HTML5 native audio, so this thing doesn’t work at all on IE (unless you’re running IE9; I don’t know what the capabilities of IE9 are yet).  Basically it works on latest & greatest: Chrome, Safari 3, Firefox 3.6 (maybe 3.5?) and so forth.  The whole project took approximately 10 hours of development time.

Nine Amazing Hours

Critiques, comments, suggestions are all welcome.  The functionality is what I want it to be; if you want a full-fledged meditation timer well, maybe I’ll do that next.

And one beg: The idea behind these projects is to learn how to, as my design teachers put it, “design, develop, market and maintain a project.”  I have no idea how to market something like this.  How would I go about telling people about it?

According to a service that tracks such things, the most popular types of websites people put for which there is a subscription fee include (in order from most to least popular)

• How to lose weight
• Health products – Vitamins, minerals, colon blow
• Starting a home-based business
• How to make money from your existing business
• How to market on the Internet
• How to make money through investments
• Personal improvement
• How to turn a hobby into a business
• How to move to a new state/country
• How to practice your religion

I’m not sure why, but I find this list incredibly sad. There are so many decent sites out there that give this information away, and most of what’s behind the paywalls is pure bullshit not worth the pixels it’s drawn with.

This just confirms what one commenter said earlier: most people don’t want a well-made website. Well-made websites scare people into thinking there’s trickery, deceit, and too much intelligence behind them for the individual to keep up with. Stupidity sells.

I was going to respond to this on genehack, but recovering my password proved to be onerous, and besides, the issue is an important one worth discussing.  John SJ Anderson wrote:

Elf digs into some Javascript on a particular high-traffic site. In the same way that some people love reading about high-performance cars or bikes they’re never going to own or even use, I love reading about deconstruction of these optimizations that are only worth doing on a tiny, tiny fraction of ultra-high traffic sites.

The Digg trick has nothing to do with high-traffic.  It’s about user experience and page size.   Even the smallest website can have large individual web pages. As HTML5, CSS3 and Javascript become the backbone of user experience, it becomes necessary to replace default behaviors with explicit ones, and adapt the style of elements programmatically.

The early way to do that was to just throw javascript at the problem an pray the DOM was available when the script ran.  The next-wave solution was to put javascript at the bottom of the page so that DOM elements to be manipulated by javascript were guaranteed to be available.  Current wisdom is to put the Javascript back in the header, but use $(document).ready() (or its equivalent in other libraries) to hook up all behaviors, timers, and event managers to the appropriate DOM object.

The current wisdom has a flaw: pages take time to download and parse.  While the page is in transition javascript-dependent display elements look ugly and javascript-dependent event managers drop down to their default behaviors– often no behavior at all, or worse, undesired anchor behavior.

The Digg technique ensures that when elements are rendered the correct programmatic styles and behaviors are simultaneously set.  Instead of waiting for the complete DOM to load, the Digg technique runs element-specific javascript when the associated DOM object is ready.   Anxious users quick on the mouseclick will get to where they want to go, even if the page isn’t done loading.  Persnickety types won’t see the designer’s elegantly designed carousel momentarily displayed as an ordinary, prestyled linked list.

Although I’m mostly a developer, I care about design.  A lot.  The Digg technique solves a serious problem in web design– making buttons do what we say they’ll do, making pages look the way we say they’ll look, and keeping backstage what belongs backstage.  Any website can use this technique, and any website with customers should.

From twitter: TheOnion.com has migrated to Django. If you don’t understand this, please register with your local unemployment office.

In my current development house, we have the painfully obvious “different settings for different stages of the development cycle.”  Production, obviously, isn’t in DEBUG mode so users don’t see the underlying technology when things go awry, and each dev has his own database.   The solution we’ve found is to create separate settings files with only the minor changes made, and then for settings.py to import that when loading, using the “--settings” argument to manage.py.

There is an inherent conflict between South and Fabric when we do this.  We use Fabric for roll-out from the repository to staging and production, and call migrate in the process.  We came to use South late in the development cycle, and many of our apps were converted to South long after they’d been populated with data.  We know how to do the whole “create, migrate data, drop table” migration process, but the real trick was 0001_initial.py; South “fakes” this for tables with existing data, recording that it was run when, in fact, it was skipped over in favor of the version created ages ago by migrate.py syncdb.

When we roll out to another stage, that database has no knowledge of this fakery.  Neither does South.  Fabric would call ‘migrate’ and the process would crash with warnings about how the table already exists.   So how do we get past that step?

Well, the answer would be to modify 0001_initial.py to test if the table already exists, and to skip if it does.  We need for the engine to fail only when actually accessing the data, and we need it to fail early.  Most models have a core table, the one without which the entire app would be meaningless.  In my example, that table is “stories.story”:

    def forwards(self, orm):

        # Probe for this.  If it works, we don't want to proceed,
        # because this isn't a migration, it's a build-out.

        if not db.dry_run:
            try:
                x = orm['stories.Story'].objects.all()
                return
            except Exception, e:
                pass

Now, if the database table doesn’t exist, the ORM handler will throw an exception and we’ll proceed to build the table. If it does, the table already exists and we shouldn’t proceed.

  I would be totally remiss in my duties if I didn’t remind you that I had some Tron fanfic of my own, now wouldn’t I? Data Flow is M/M, and a warning for non-consensual sex.

Meanwhile, enjoy staring at the totally hot chick. If that’s Mercury, damn, that’s a lot of nice polygons.

This is probably a “no-duh” to some people, but I had not known this. When you upload something to the CDN, you get a url that looks like this:

http://cdn.mycompany.com/images/someimage.jpg

Which is all fine and good. Django’s MEDIA_URL is usually suffixed with a closing slash, meaning that if you’re in the habit of typing something like %(foo)s/images/someimage in a standard python template, you’re going to end up with:

http://cdn.mycompany.com//images/someimage.jpg

And the CDN throws a wobbly. Most djangoites know to write the template as {{ MEDIA_URL }}images/someimage.jpg apparently. I need to build that habit. Apache is forgiving. Amazon is not.

A few weeks ago, I installed the latest version of the Gnome Accessibility Toolkit (Gnome-AT), and while I never quite got it to work the way I wanted to, it didn’t seem to be doing any harm.  I figured once I got to the point of showing the client the work we’d talk about accessibility issues.  (Many of her clients have low vision problems, so making the site super-accessible is super-important.  I’ll have a post soon about making specific zones of your websites auto-sizeable in an elegant way with jQuery.)

It turns out that it wasn’t working because I hadn’t stopped and restarted X. So, when I did that after installing some new fonts, everything went kablooey. The most tragic was Emacs, which grabbed the mouse and keyboard and never let go. Very annoying. I had to kill X remotely, logging in through my Palm pilot (which isn’t much fun, believe me.)

The problem with very stable OS’s is that when they go unstable, the events that caused the instability may be separated from the experience of instability by days, even weeks. In this case, four weeks. It wasn’t until X had died for the third time– this time is a screen session I had accidentally started it in, but which luckily preserved the output of X’s error log– that I finally saw Emacs spitting out all these “at-lock-FAIL” warnings and wondered what the heck those might be. A quick un-install of the accessibility components and I’m back up and running, but man, that was annoying.

No great announcements, just a few writerly things I saw today:

#1: Regarding my recent reviews of Jeanette Winterson’s The Stone Gods, Jo Waltonnails my opinion to the floor:

The techniques of writing and reading [science fiction] have developed in that time. Old things sometimes look very clunky, as if they’re inventing the wheel—because they are. Modern SF assumes. It doesn’t say “The red sun is high, the blue low because it was a binary system.” So there’s a double problem. People who read SF sometimes write SF that doesn’t have enough surface to skitter over. Someone who doesn’t have the skillset can’t learn the skillset by reading it. And conversely, people who don’t read SF and write it write horribly old fashioned clunky re-inventing the wheel stuff, because they don’t know what needs explanation. They explain both too much and not enough, and end up with something that’s just teeth-grindingly annoying for an SF reader to read.

Exactly right, and that’s what’s wrong with everything fromWinterson’s The Stone Gods to the atrocious “science fiction” of e-book only romance writers like Jet Mykles and Reese Gabriel.

#2: The Five Stages of Publishing. See, I skipped down to acceptance right from the beginning. And it’s always worked for me.

#3: I’ve been writing again, and it’s been an iffy thing. The skill comes and goes like a guilty whoremonger. But I received an invitation for an anthology of “Queerpunk,” and have been thinking about how to work cyberpunk, homosexuality, near-future transhumanism, and I think I have an opening:

I met him in the one place where we could possibly have met: on a de-orbiting shuttle. I was coming back from another freelance job in orbit, all wracked out and drained but carrying so much new knowledge it had weight. He had a suit, and a tie, and all the signs of a lunar career.  We’d have never met if it hadn’t been for the blackout, that fifteen minutes of silence when you’re cut off from the net.  We were forced to talk to each other.  Hell, we were forced to notice each other.  Which wouldn’t have happened without the blackout.

Our seats were side by side.  But he had all the newest stuff, corporate double-signed and encrypted with Diffie Hellman Six, every one of them with a publicly visible EULA and the checkmark box visible should the Pirate Corps come looking.  And me?  Diffie Hellman nine but GPL’d, man… all the way.

I’m not sure where to go from there. I know I have to get them into bed and emotionally involved, but what’s the plot? Hmm…