Technology

The three are from 2013, so details may have changed, but they seemed useful enough that I’ve had them open in my browser for a while:

• http://kadamwhite.github.io/talks/2013/backbone-wordpress
• http://code.tutsplus.com/tutorials/using-backbone-within-the-wordpress-admin-the-back-end–wp-30056
• http://code.tutsplus.com/articles/using-backbone-within-the-wordpress-admin-the-front-end–wp-30121

On wp-hackers, Haluk Karamete asked:

on admin pages, how can I detect that the current admin is dealing with a cpt?

Andrew Nacin answered:

get_current_screen()->post_type.

[But] this will also specify a post type when it’s a taxonomy being edited. To filter that out, ensure that get_current_screen()->base == 'post', which is [true] for edit.php, post-new.php, and post.php (for all post types).

Haluk didn’t elaborate on the cause of the question, but the answer is very good advice for those seeking to conditionally enqueue JS and styles only for specific post types.

http://www.fernjager.net/post-8/sdcard:

As a 400 MHz Linux system with 32 MB of RAM, using only ~100 mA @ 3.3 V, the possibilities are endless!

http://haxit.blogspot.com/2013/08/hacking-transcend-wifi-sd-cards.html:

This post is written with the intention of exposing not only the exploits which will allow you to root (or jailbreak) the device, but also the process of discovering and exploiting bugs, some of which are a dead end, while others lead to the holy root B-)

http://hackaday.com/2013/08/12/hacking-transcend-wifi-sd-cards/:

As he suspected that some kind of Linux was running on it, he began to see if he could get a root access on it… and succeeded.

In a typical LAMP environment, but don’t have or can’t trust that mcrypt is available in PHP? Try MySQL’s AES_ENCRYPT and AES_DECRYPT. Go read the docs.

From the codex for esc_js:

If you’re not working with inline JS in HTML event handler attributes, a more suitable function to use is json_encode, which is built-in to PHP.

The  storage engine docs are quite clear — “the CSV storage engine stores data in text files using comma-separated values format” — and yet I never realized MySQL supported it.

Sure, the tables don’t support indexes and repairing them seems riskier than with other tables, but it still seems to offer a lot of convenience for some things. A comment in the docs suggests how easy CSV exports can be:

A comment suggests this super easy export to CSV approach:

CREATE TABLE csvtable SELECT * FROM innodbtable;
ALTER TABLE csvtable ENGINE=CSV;

That said, I really can’t imagine using it in production, or even as part of a repeated workflow.

It should be simple, but I ran into a number of errors.

First I got stuck on libtool: line 990: g++: command not found. It turns out I needed to install g++ using:

yum install gcc-c++

Then I got stuck on this one:

platform.h:110:2: error: #error "Can not compile without isnan function or macro
[...]
"Coordinate.inl:38: error: ‘ISNAN’ was not declared in this scope

The author of this page faced the problem, but the real insight came from this bug report on an unrelated project:

In these versions of g++ isnan is defined as a macro in <math.h> unless is included, in which case std::isnan() is defined instead.

And so I tried replacing #include <math.h> with #include <cmath> in include/geos/platform.h. Amazingly, that worked.

WordPress appears to continue with execution even when MySQL refuses connections/queries after init. Here’s a comment in the MySQL docs suggesting how to detect the condition in raw PHP:

$link = mysql_connect("localhost", "mysql_user", "mysql_password");
if (mysql_errno() == 1203) {
  // 1203 == ER_TOO_MANY_USER_CONNECTIONS (mysqld_error.h)
  header("Location: http://your.site.com/alternate_page.php");
  exit;
}

Just a note to myself, but I wonder if there’s opportunity here.

world.geo.json

To mock something fast and loose with geo-json data for the world, this is your fix. Legal status of this dataset: dubious?

For a good time, drag them to http://bl.ocks.org/1431429 and paint the globe!

world-atlas

[A] convenient mechanism for generating TopoJSON files from Natural Earth.

Natural Earth

Natural Earth is a public domain map dataset available at 1:10m, 1:50m, and 1:110 million scales. Featuring tightly integrated vector and raster data, with Natural Earth you can make a variety of visually pleasing, well-crafted maps with cartography or GIS software.

Natural Earth solves a problem: finding suitable data for making small-scale maps. In a time when the web is awash in geospatial data, cartographers are forced to waste time sifting through confusing tangles of poorly attributed data to make clean, legible maps. Because your time is valuable, Natural Earth data comes ready-to-use.

From the MySQL manual:

For any Unicode character set, operations performed using the xxx_general_ci collation are faster than those for the xxx_unicode_ci collation. For example, comparisons for the utf8_general_ci collation are faster, but slightly less correct, than comparisons for utf8_unicode_ci.

They have a amusing “examples of the effect of collation” set on “sorting German umlauts,” but it unhelpfully uses latin1_* collations. And another table that helpfully explains:

A difference between the collations is that this is true for utf8_general_ci:

ß = s

Whereas this is true for utf8_unicode_ci, which supports the German DIN-1 ordering (also known as dictionary order):

ß = ss

This forum post adds more info, but nowhere do they explain how a ☃ sorts against ☁ or ⛅.

How much faster is utf8_general_ci than utf8_unicode_ci, though? An August 2010 message in the MySQL forums seems to suggest the performance for specific operations could be 30% faster, but then dismisses the performance difference as unimportant compared to good indexing and writing efficient queries.