Programming

I manage a handful of websites, like this one. Having built a few on other platforms, such as Drupal, I’m familiar with the dreaded error “The website encountered an unexpected error. Please try again later.” On sites that I don’t check on frequently, it can be an embarrassment when people begin emailing you with questions about the site being down.

I wrote the following Python script to deal with the problem:

Hazel and DEVONthink make a great pair as I’ve written before. Using AppleScript, it’s possible to take the import workflow even further by tagging incoming files automatically.

Use case

I download a lot of mp3 files containing pronunciation of words in a language I’ve been learning. I keep a record of these words and tag them appropriately using my hierarchical tagging system.

I’d like to download the files to a directory on the desktop. Keep them there for a few minutes until I’m done working with them, then import the file to DEVONthink Pro Office, tag the file there and delete the original.

I’m a fan of using metadata to classify and file things rather than declarative systems of nested folders. Most of the documents and data that I store for personal use are in DEVONthink which has robust support for metadata. On the email side, there’s MailTags which lets you apply metadata to emails. Since MailTags also supports AppleScript, I began to wonder whether it might be possible to script workflows around email processing. Indeed it is, once you discover the trick of what dictionary to use.

I have a number of AppleScript applications that need to run at odd times. These maintenance tasks often attempt to run while the computer is sleeping. Particularly those that rely on UI scripting do not function during this period.

This most flexible way of dealing with this is to manipulate the power management settings directly via the pmset(1) command.

The variety of options available using pmset is staggering and beyond the scope of this post. Here’s what I do to wake the computer up at specific times so that scheduled AppleScripts can run:

I use Anki to study foreign language vocabulary. It’s the de facto spaced repetition software for memorization.^[Yes, I’m aware that others exist. I’ve tried many but always have come back to Anki.] When making flashcards for language learnings, I try to use imagery as much as possible. So a card may have a Russian word on one side and just an image on the opposite side. (Since I already know the English word that the image represents, why not try to engage a different part of the brain to help with memorization?)

Hexo, the static blogging system that I use is very extensible and provides numerous hooks into generation pipeline.

While working on a Russian language blog that’s coming online soon, I had the opportunity to write a filter to render Cyrillic text in a different font than the rest of the body text.

I wanted to set the Cyrillic text apart both in color, typeface, and font weight. Although I could have extended Hexo using a new tag, I decided to use a filter so that after rendering HTML anywhere on the blog, items demarcated by double pipes || would be replaced by a new <span>.

Because the blogging system that I use doesn’t apply finely grained object-level caching rules, I end up with objects such as images that cache appropriately but an index.html page that does not. I don’t want client browsers to hang on to the main index.html page for more than an hour or so because it should update much more frequently than that as its content changes.

It’s possible that I could dig around under the hood of hexo and create a version that applies customized caching rules. Instead, I make a second pass over the content, adjusting the Cache-Control and other metadata according to my needs. For this task I use the Amazon Web Services command line interface AWS-CLI.

[N.B. 2016-03-26 Nathan Ifill pointed out that it is possible to use Anki’s built-in conditional replacement feature to do what I’m illustrating. I’ll have to work on another example!]

Anki is a widely-used flashcard application. If you’re learning a foreign language and you’re not using Anki, you should be.

If you are using Anki and are picky about the appearance of the cards, you should know that JavaScript can be used in the card template. This opens up a number of possibilities for dynamic cards. I’m just touching on the technique here.

How to identify Russian letters in a string? The short answer is: [А-Яа-яЁё] but depending on your regex flavor, [\p{Cyrillic}] might work. What in the word does this regex mean? It’s just like [A-Za-z] with a twist. The Ёё at the end adds support for ё (“yo”) which is in the Latin group of characters.

See this question on Stack Overflow.

I recently migrated this and my other blog to Hexo which is a very fast static blogging framework built on node.js. As when I used Octopress, this blog is still hosted from an AWS S3 bucket. However the deployers that I tried with Hexo failed because of dependencies that were incompatible with the OS X version I was running. Not being a node.js expert, and having no time to delve into node.js internals, I wrote a new deployer: