John Kawakami's blog

Are Doctests in Django 1.8 Failing to Run?

I don't know what's up, but I ran some old examples, and it looks like doctests aren't running when I do the " test" (or the one with a settings file).

CORS, Angular JS, and, together, didn't let me login twice.

Things were going well with a re-architecting and re-factoring of a service to use Angular's awesome $request, and Django REST Frameworks' awesome ModelViewSet generics. As usual, when things are chugging along, you come across a weird bug that just sucks you in for a while. The bug I hit today involved CORS, AngularJS, and Parse (we're using Parse for part of our backend).

The symptom was that, if I logged in once, then logged out, I could not log in again. I could reach the server, but it wouldn't let me do the exact same thing I'd done just 30 seconds before.

Hating on HATEOAS a little bit, thinking about it a lot

I've been thinking about how to enable HATEOAS on this web app, and it is a mind-bender. Django isn't quite up to it - but it does have a key feature of named links and URL generation that seems like a requirement for HATEOAS. To do HATEOAS, links need to be elevated to a higher status in the system.

For one, on the web, links are very different from the way software internals are organized. In software, and also in URLs, we have hierarchies: paths to files, paths to APIs, hierarchies of objects, and nested data structures.

Log Everything: Send Shell Commands to Syslog

This is an article on security, but I started to record all my commands to syslog so I can track what I'm doing, when, and for how long, more or less. Then I record this on my calendar to see if I'm staying focused on work, or getting distracted. It's a nice blog post.

Bash History to Syslog

Edit: so I implemented it on my computer, but changed it slightly:

# log all my commands
function log2syslog
     declare command
     command=$(fc -ln -0)

Not Hating on HATEOAS

There's been some loving and some hating on HATEOAS (which I don't know how to pronounce), but I'm starting to get it. See: REST Cookbook, Timeless, and PayPal's API.

The core idea is, in addition to the data, you send over some information about the possible URLs you can use as a next step.

Finding anagrams in a list

I was reading quora and came across a post about someone who was rejected from facebook for a sloppy answer. The question was to make a list of words where the anagrams were grouped at the top.

People consoled the guy.

The answer seemed like a unixy thing. It's not that hard, the trick is to create an index for each word, where the index is the word, sorted by letter.

Demo of rotating an element to make a "dial" or "knob" ui element

Here's a little bit of code that shows how to create a "dial" knob that you can control with the mouse. It's entirely in HTML, CSS and Javascript.

It's not hard, but there are a lot of little details to make it look reasonable and not completely goofy. I think it moves a little weird - and it should respond to both x and y axes, but doesn't.

The sum of two sines, with an offset.

Cast any Javascript Value to a Boolean with Double Exclamation

It's a way to cast any variable to a boolean.

var x = true;

!!x === true; // this is a fact

Sometimes, we do a check on an object:

if ( {

However, if we assign a variable like this:

var isFoo =;

isFoo will now contain a reference to 
If you want isFoo to contain the truthyness of, you do this:

var isFoo = !!;

Nesting Angular Directives

I've been learning how to write directives, and it's really tough to grok how to do it. This blog post's been rewritten three times so I don't come off as totally ignorant about the "right way" or "the Angular way" to do things.

What I'm trying to do it implement a menu display with lightweight, role-based control over what is displayed.

My first iteration was done entirely with controllers, HTML, and jQuery and plain Javascript. That was clearly not the Angular way, so I revised it a little bit - CSS animations, and let's use directives.

Angular Service and Factory

I was reading the docs, and read things that seemed to contradict what I thought. I thought that Services were singletons, and Factories were instantiating new instances. It turns out that's not quite right. It's explained well here.

Base32 Encoding and Decoding in Javascript

This is a simple implementation of base 32 encoding and decoding that conforms to RFC 4648.

CSS Animations via Styles (similar to jQuery animations)

This explores how to do CSS-style based animations, where the animations are controlled via Javascript code that adds and deletes class names from the className property.

Cloud Storage Reviews Dropbox, OneDrive, Google Drive, iCloud

If you want to read some professionally written reviews, I read these:
PC Advisor
PC Mag
My review will be a lot shorter: Dropbox. Explanations below.

I Think I Got Scammed - My Battery Desulfator Experience

I just bought one of those "battery desulfator" devices on ebay. The brand was, but there are numerous different brands, and there are some that are added to battery chargers. This essay explains why I got bamboozled.

A funny RAID 1 failure factoid: you will fail more

A funny thing about RAID 1 disk mirroring, is that if you implement it on your computer, you're more likely to experience a failure. The trade off is that the failure won't be catastrophic.

Syndicate content