Script to Turn IP Camera Uploaded Images into Videos (Unix)

This script combines individual photos into a video, and adds a timestamp to each frame. It's a poor mans security camera video maker.

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.

Setting up the HP P1102w with Linux Ubuntu Gnome

The printer stopped working, so I had to look for instructions. Things have changed a lot since I got this printer. Originally, it required the proprietary HP drivers and utilities, because CUPS didn't have any support. It worked, but was a bit of a pain, and required running a program on the workstation, creating an hplip printer, and printing through that. It worked... but then the drivers stopped working. (Since I print so infrequently, I don't know when they stopped working.)

Django, forcing a specific migration

Migrations are awesome magic, until the magic fails. Then it's an awesomely frightening engine of change that threatens to wipe out your entire database.

So, before doing what I say, backup your database.

I had to enforce a "unique=True" constraint on a model. Migrations are supposed to automatically create a constraint in SQL, as well as its implied index. A quick look at the indexes (SHOW INDEXES FROM Model) didn't show the index.

Battle of the Naming Conventions (how to avoid them in Django REST Framework)

Python and Django like snake_case.

AngularJS feels like Java, and likes camelCase.

HTML likes dashed-words.

MySQL docs like snake_case, but I see more PascalCase used in databases. It's case-sensitive, too. uses PascalCase for tables/classes, and camelCase for columns/properties/fields. That's like Java OOP.

Django likes to append _id to your primary keys.

So... the problems start to happen when one piece of named data is passed from one layer of the system to another. It's just a good policy to use the same names at all layers, if possible.

Django migrate MySQL error 1005 105, can't create table

When you have Django's migrations making foreign keys, you might hit this error, number 1005 or 105.

This may be happening because foreign key constraints can be applied only to identical columns that are unique.

So, check that they're unique, and add an index. (If you try to add the index, it'll fail if the values are not unique.)


Then, if you still get the error, check that the character sets are the same on both tables. (I don't think Django's db reflection keeps track of that.)

Buttons vs. Links, and how to make buttons that look like links, and act like links, but aren't links.

This is a common UI element that hovers between "pattern" and "anti-pattern", but it's one I've seen in Drupal, WordPress, and a few other places. It's the button next to a link, where the link acts just like a button:

Technically, it's a violation of UI principles, to have a link that does something to the server's state. Anthony at uxmovement thinks so, but I disagree with him, because the way the link is next to the button, it's obvious that it complements the button.

Benchmarking String Function to camelCase

I needed a function to turn snake_case to camelCase. The reason why? Angular and Javascript are better with camelCase, and Python and Django prefer snake_case. I tried working with both in the Django side, and it wasn't pretty. Even worse, I lost track of when I switched from one to the other, if I switched at all. So, I'm going to try renaming the keys as they are handed off from Django Rest Framework to the Javascript.

No Wonder My PulseAudio Stopped Working

The microphone stopped working on my computer. Based on my reading, the problem, I think, is that I'm using an older motherboard from around 2010s, an add-on card that does TV, and Ubuntu with PulseAudio. The mic input on the sound card just stopped appearing in PulseAudio.

It's still visible in ALSA.

A Django REST Framework Technique for more Detailed Related Records

This is a nice way to deal with building lists of objects to display in tables. It's kind of hidden in there, but in your serializer, you can specify that a field is represented by another serializer.

The result is a list of objects instead of a list of URLs or PKs.

Now, going with that, you can save on data transfer by serializing only a few fields.

My .vimrc

set nocompatible " be iMproved, required
filetype off " required

" set the runtime path to include Vundle and initialize
set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()
" alternatively, pass a path where Vundle should install plugins
"call vundle#begin('~/some/path/here')

" let Vundle manage Vundle, required
Plugin 'gmarik/Vundle.vim'

" All of your Plugins must be added before the following line
call vundle#end() " required
filetype plugin indent on " required
" To ignore plugin indent changes, instead use:

Intermittent Django REST Framework glitch examined with Apache Benchmark

While programming in the rest framework, I hit this error, intermittently, but over and over, along with others:

Could not resolve URL for hyperlinked relationship using view name "parseuser-detail". You may have failed to include the related model in your API, or incorrectly configured the `lookup_field` attribute on this field.

Being a noob, I hit the books (documentation) again, and again, and thought I had it right, or close. (Don't start out creating Django models for non-Django-managed tables. It's pretty hard. It's better to learn the vanilla Django way first, if possible.)

Instant Cross-Domain Access for Everyone with CORS in PHP

Here's a snippet of code that will make your PHP REST API work cross-domain, through the magic of CORS:

 * CORS is a way to allow scripts from other domains to post to this URL.
    header('Access-Control-Allow-Origin: *');
    header('Access-Control-Allow-Methods: POST, OPTIONS');
    header('Access-Control-Allow-Headers: Content-Type');
header('Access-Control-Allow-Origin: *');

Django Rest Tutorial, Inverted

[I hesitate to post this, because it makes me look like I'm a slow learner... but, oh well. I hope someone finds this interesting.]

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