If you’ve visited my site more than once, you might start to notice that the silly little tagline next to the logo in my header changes, in both content and appearance.

This is accomplished by way of a fancy little bit of PHP. The image generation uses the GD library (with FreeType support), and the fonts are all TrueType.

Again, since my Linode didn’t come with anything preinstalled, I needed to install GD first. It seemed like it might be a bit of a pain - the PHP manual page indicates I was going to have to recompile PHP. Fortunately, this was not the case.

I just had to download it from Ubuntu’s package manager…

apt-get install php5-gd

…and add it to the “extensions” section of php.ini…

nano /etc/php5/apache2/php.ini
 
extension=gd.so

…and restart Apache.

apache2ctl -k graceful

Once that’s out of the way, creating the image was remarkably simple - especially since I found a ready-made script that did exactly what I wanted.

The code is pretty long, so hit the jump to see the rest.

Read the rest of this entry »

There’s a handy little query you can run in SQL to retrieve the identity (primary key) value of a record you just created. So, you can do something like this:

INSERT INTO
  People (
    Name
  ) VALUES (
    'Joe'
  );
  SELECT @@IDENTITY AS NewName;

This query will create a new person and also return the identity value of the newly created record. It can be useful for all kinds of things - I use it frequently.

We recently upgraded to ColdFusion 8 here at Purdue, and my code started breaking.

It turns out that CF8 attempts to “help” you by automatically running SELECT @@IDENTITY after any INSERT query. This is problematic in two ways - it cancels out your own @@IDENTITY query, and it arbitrarily names the result Generated_Keys.

So instead of being able to do something like this:

<cfset TheNewName = People.NewName>

You must use this:

<cfset TheNewName = People.Generated_Keys>

It’s really more annoying than anything else. It seems like a good idea to include the code automatically, but I think it would probably be a little better if there were a conditional in there that prevents CF8 from inserting its automatic query if a SELECT @@IDENTITY query is already present.

Not too long ago, I wrote a short tutorial on using ColdFusion to identify the user’s browser and add extra browser-specific CSS files. Today, I found myself in need of similar functionality for PHP. The code isn’t quite the same - PHP doesn’t have a direct clone of CF’s contains decision operator; you have to use the strstr string function instead. The general idea, however, is the same.

The following script will identify between Firefox, IE6, and IE7. Like my last post, I’ve added an extra piece that will include an ie.css file before including an IE version-specific stylesheet.

<?php
  $thePath = "/css";
  $absPath = $_SERVER['ABSOLUTE_PATH'] . "css";
  $theBrowser = $_SERVER['HTTP_USER_AGENT'];
 
  if(strstr($theBrowser, "Firefox")) {
    $browser = "firefox";
  }
  elseif(strstr($theBrowser, "MSIE 7.0")) {
    $browser = "ie7";
  }
  elseif(strstr($theBrowser, "MSIE 6.0")) {
    $browser = "ie6";
  }
 
  if(file_exists($absPath . '/' . $browser . '.css')) {
    $css = '<link rel="stylesheet" href="' . $thePath . '/' . $browser . '.css" />';
  }
 
  if(strstr($browser, "ie")) {
    if(file_exists($absPath . '/ie.css')) {
      $css = '<link rel="stylesheet" href="' . $thePath . '/ie.css" />' . $css;
    }
  }
?>

The ABSOLUTE_PATH server variable tells us where our site is actually stored on the server; I added the name of the directory where my stylesheets are stored to the end of the variable and stuck it in a string called $absPath. You’ll need this absolute path to determine if a CSS file exists in the given directory. The relative link to my CSS directory is stored in $thePath and is used to link to the CSS file in my HTML.

When the code is done, I’m left with two variables I can use anywhere in my application: $browser is the short identifier for the user’s browser; $css contains the HTML to link to the additional stylesheet(s).

It’s the same concept with a slightly different implementation. Happy coding!