John Doe's personal blog

Sorry for the break – I spent the past week or so frantically preparing for, and then attending, my Director’s annual off-site planning meeting. As always, it was a valuable experience – the opportunity to interact with Managers in a more relaxed setting, and to see how each of us attacks a given problem from so many different angles, is incredibly cool. Plus, I got to play golf again.

Today I’m bringing you a quick example of how to use jQuery to check with a Service to see whether the user should be allowed to toggle the state of a given checkbox. In my example, the “Service” only allows you to check boxes labelled with a prime number. I’m sure there’s a more jQuery-approved method, but this one was simpler to figure out than .val() – I couldn’t figure out how to make that *un*check a box.

This past week got out of control fast, so I’m posting the Linkblog on Friday instead:

My employer uses a lot of Java, so I’m trying to brush up on the available solutions in a couple of domains – here are some ‘project managmenet’ solutions
JTrac – Java version of Trac – see above
Posterity is a web-based email system. Unlike most open source webmail applications Posterity is not just a web interface for IMAP servers..[it] uses its own database. Projects which combine mail and databases are really interesting to me.
Andrei Zmievski is one of the brightest people working on the PHP source, this page contains links to a lot of the talks he’s given at different conferences.
Something I’m looking into for BlogProj: A .net RSS Reader
I visit this blog [database-programmer.blogspot.com] about once a week, there’s always something interesting here
Review of Wrike, an online project management tool, and part of their sales pitch
Embedding JavaScript in Ruby
Data visualization of 2008 US movie box office revenues – I think there could be some interesting ways to use this visualization technique
I used to play WoW, but I always found that I preferred the idea of writing one to playing one.
These are some tools that might make that possible
Flow-based_programming – “flow-based programming (FBP) is a programming paradigm that defines applications as networks of “black box“processes, which exchange data across predefined connections by message passing…”- just when you thought you knew it all…
Mozilla is really starting to gear up to move the web into the future – check out The Concept
You’ll eventually see a series of blog posts based on the 501 movies listed in this book
Generating an SSL Certificate – I’m constantly having to look this up for people, or maybe you’d prefer the Debian Way ?
PgSQL string function reference – remind me to tell you some time about how I used these to completely corrupt my PgSQL database!
xjconf – Never enough XML parsing
table.pde, part of the code backing the excellent Visualizing Data, which I’m using to prepare my presentation for our annual Management Off-site.

I had a friend who couldn’t mysqldump a customer’s database — the best guess freenode’s #mysql and I could come up with was that the username provided didn’t have the ability to LOCK tables — so I came up with an alternate method that I thought I’d abstract it and post it here for others to use. All this assumes you can connect to the database from your host…

1) Get database schema
[highlight lang=sh]
for i in `mysql —host=$MYSQLDUMP_HOST —user=$MYSQLDUMP_USER —password=$MYSQLDUMP_PWD $MYSQLDUMP_DATABASENAME -e “SHOW TABLES” | tail -10`; do mysql —host=$MYSQLDUMP_HOST —user=$MYSQLDUMP_USER —password=$MYSQLDUMP_PWD $MYSQLDUMP_DATABASENAME -e “SHOW CREATE TABLE $i\G”;
done > schema.sql
[/highlight]

2) Dump the table contents as XML files to the local disk. I went with XML files because I had trouble getting this particular data set to dump and then import using the ‘batch’ format MySQL more natively supports.
[highlight lang=sh]
for i in `mysql —host=$MYSQLDUMP_HOST —user=$MYSQLDUMP_USER —password=$MYSQLDUMP_PWD $MYSQLDUMP_DATABASENAME -e “SHOW TABLES” | tail -10`; do mysql —host=$MYSQLDUMP_HOST —user=$MYSQLDUMP_USER —password=$MYSQLDUMP_PWD $MYSQLDUMP_DATABASENAME —xml -e “SELECT * from $i;” | tee $i.xml;
done
[/highlight] I used ‘tee’ so I could watch the tables being created, in an attempt to gauge how much work was left. You could just as easily replace “| tee” with “>”.

3) Turn the XML files into INSERT statements. I did this with Python and lxml – you could use just about anything that has a decent XML API.

import.py
python import.py > inserts.sql

4) Create the database, run the INSERTs.
[highlight lang=sh]mysql -e “CREATE DATABASE $MYSQLDUMP_DATABASENAME;”
mysql $MYSQLDUMP_DATABASENAME < schema.sql
mysql $MYSQLDUMP_DATABASENAME < inserts.sql[/highlight]

Hope that can help someone else.

I picked up The Name of the Wind on the recommendation of Radar – when I first opened the book, I was gravely concerned – my experience has previously shown that the more glowing reviews a book got, the more likely it is that the book would not have sold without those reviews, and this book had no less than three full pages of raves. However, I went against my own judgement and have thus far been glad. If you decide to pick it up, do me this favor – stick with the story long enough to see Chronicler deal with highway robbery. If you still don’t like it by that point, at least I won’t be able to say you didn’t give it a fair shake.

PHP5’s XMLReader – which I used for my JSON-Like XML post, doesn’t implement a ‘clone’ handler, which came as quite a shock when I attempted to implement a wrapper class that would allow me to push values back into the stream when I had to read-ahead to implement ‘nested data structures’ as suggested by Davey. I had a hard time finding a good example of how to internally implement clone (even Sara Golemon’s book only gives it a brief mention¹), but I finally came up with something – I’m building it now to see how well it works, or even if it works at all.

¹ zend_object_value clone_obj(zval *object TSRMLS_DC) – Used to generate a new object copied from an already instantiated one. The default behavior is to create a new object instance, associate the original’s handler table with it, copy the properties table and, if the class entry for the object in question defines a __clone() method, call that to allow the new object to perform additional duplication work.

Stuff in my backlog from last week:

1. Pragmatic Progressive Enhancement – Thanks Matt
2. Dot – The Userguide – Watch this blog for an upcoming project related to dot/graphviz!
3. Arguing with Users – I was one of the many users disappointed enough by Pidgin to “migrate”
4. Learning Perl the Hard Way – Maybe PHP needs one of these?
5. Tamarin project @ Mozilla – I want to see how this compares to SquirrelFish – can I actually get my hands on WebKit nightlies somewhere?
6. Javascript 2 – A Perl 6 Disaster – I must be the only person left who likes where JS2 is headed?
7. Mozilla 2 Roadmap – Anyone know of a more up-to-date version?
8. Ada Programming Book – Well, it’s definitely not Java; guess it’s time to really knuckle down and learn some real Ada.
9. The Wannabe Developers Manifesto – ##PHP often leaves me feeling this way
10. Oink – C++ Static Analysis
11. Wikipedia – List of Revision Control Software – I need to make my own “Matrix” site, like cmsmatrix.org – but abstracted to accept lists such as these.
12. TIOBE Index – PHP holding strong at #5
13. Join-Fu Slides – A series of talks by a MySQL employee, I’d like to compare some of his speed claims against other engines, see how much is MySQL specific – am I the only one who prefers Theta syntax?
14. A PgSQL Blog: CONNECT BY in 8.3? – I use this feature quite often in Oracle 10g, glad to see it making its way to the OSS engines.

Question for readers: Do you know of a good ML book? O’Reilly and Associates doesn’t seem to have one, nor Prentice-Hall PTR, and I never know who I can trust from the other publishers – they’ve been far too spotty in my experience.

Note to self: Make Textile plugin open links in _blank

#phpc on Freenode had a discussion tonight about how there’s nothing in XML that’s quite as simple as JSON for encoding types. I came up with this off-the-cuff – as opposed to WDDX, this is more JSON-like in that each ‘XML Document’ encodes only a single value – but that value might be mapped to any of the built-in types.
Of course, the <object> stuff would only work with pretty simple objects – but the fact that it tries at all to instance a class is a step beyond what JSON does, which is ALWAYS an instance of stdClass. You could drop this extra ‘feature’ by remove removing line 43 ($class = …) and changing line 44 to:
[highlight lang=php]$data = new stdClass;[/highlight]

[highlight lang=php] public function offsetSet($key, $value) { if ($key === NULL) return $this->push($value); $this->throwEx(array(‘Do not directly set indices in a %s, use push() instead’, CLASS)); return false; }
[/highlight] This allows the use of PHP’s ‘push’ syntax: $foo[] = ‘bar’;
Full class after the jump.

I liked the SPL I used in my last post, so I cracked open my Python Cookbook to a random location and decided to try and implement whatever it landed on in PHP using SPL – that led to the following implementation of a ring buffer.
There certain may be better ways to do it, but this was my first pass, and I think it behaves much how you’d expect a ring buffer to.

Someone in ##PHP was looking for an array that had ‘case-insensitive’ keys, so I threw this together using SPL