Matthew Byrne: the blog » php

Form breaks WordPress

admin — Mon, 26 Jan 2009 19:26:18 +0000

Just spent the last hour trying to figure out why a simple php form was breaking WordPress. The answer was a variable name clash. I used a variable called ‘name’ in my form which seems to be linked the WP tag tags (!).

To get things working I renamed ‘name’ to ‘signUpName’.

Whilst scrabbling around for answers I did come across a good article about a security vulnerability when using the PHP_Self command, it’s well worth a read before you build your next form.

Postcode Widget – Part 3

admin — Mon, 25 Aug 2008 10:59:38 +0000

You can see a prototype version of the widget by clicking here.

Template engine

I attempted this built as single piece of php but it quickly became obvious that this was not the right approach. Instead I adapted a simple template engine from my faithful O’Reilly book. This allowed me to separate the logic from the markup

function FillTemplate($inName, $inValues = array()){

	$theTemplateFile = $_SERVER['DOCUMENT_ROOT'].'/templates/'.$inName;
	if($theFile = fopen($theTemplateFile, 'r')){
		$theTemplate = fread($theFile, filesize($theTemplateFile));
		fclose($theFile);
	}
	$theKeys = array_keys($inValues);
	foreach($theKeys as $theKey){
		$theTemplate = str_replace("\{$theKey}",$inValues[$theKey],$theTemplate);
	}

	return $theTemplate;
}

Map Logic

Here’s the source for the Map Logic. As an attempt to make the script secure you can see I’ve used a UK Postcode Regex from Stuart Wade to validate the form input. And also mysql_real_escape_string() on any database calls.

Any security tips would be greatly appreciated

The Map Logic uses four separate templates to handle the interaction, and the error state.

Integrating script with WordPress

After developing this script I discovered that WordPress can’t run PHP in the body of a post without a plugin. Strange. So I had to put the prototype on a loose page.

Take a look at the trick I used to capture the output of a WordPress tag so I could incorporate it into Map Logic, and then my templates. In this example I captured the footer code, then bound it to a template tag.

The SEO experiment – Part 2 Google Rank graphic

admin — Sun, 17 Aug 2008 17:26:56 +0000

A sites position on Google work like this:

Position = Relevance of content * Google Rank

So, knowing my current Google rank is going to be handy. There are a bunch of different ways to discover a sites rank from the Google Toolbar, to a million and one websites. As I want to chart the progress of this site I also need a way to periodically record my results.

I need the following components: a script to periodically measure Page Rank, a database to store the results, and a script to chart the results.

Page Rank Script

After a quick search I came across a great Open Source Google Rank script. This script returns code for a graphic so I rewrote the function pr_image($pagerank) to return a number instead.

The Cron job

I set up a Cron Job to periodically call the following script. (This script is placed outside the html directory for security).

<?php
//Connect to the database
include 'connect.php';

//Include the Page Rank script
include("pagerank.php");

$today = date("Y-m-d");

//Discover the current Page Rank
$gpr= new pageRank();
$gpr->printrank("http://www.matthewbyrne.co.uk");
$pageRank = $gpr->get_pr();

// Insert a row of information into the table
mysql_query("INSERT INTO googlePR (theDate, rank) VALUES('$today','$pageRank' ) ") or die(mysql_error()); 

//We've finished with the database, so close the connection
mysql_close($conn);

?>

Charting the results

The results are displayed live in chart (to the right). This script still needs a bit of work, as it will run off the edge of the graphic after a couple of months, but for now does the job just fine. Also, it looks a lot nicer when the bars are not all zero, so I’m keeping my finger crossed that Google moves me up a rank or too.

<?php
//Connect to the database
include 'connect.php';

//set up image
$height = 120;
$img = ImageCreate(230,$height);
$white = ImageColorAllocate($img,0xFF,0xFF,0xFF);
$black = ImageColorAllocate($img,0x00,0x00,0x00);
$blue = ImageColorAllocate($img,0x14,0x8A,0xD6);
$grey = ImageColorAllocate($img,0xCC,0xCC,0xCC);

//Query databasebase
$query= "SELECT * FROM googlePR_MB";
$data = mysql_query("SELECT * FROM googlePR_MB")
or die(mysql_error()); 

//Build array
$results = array();
while($info = mysql_fetch_array( $data )){
	$reformatDate=date('d M',strtotime($info['theDate']));
	array_push($results, array($reformatDate,$info['rank']));
}
//We've finished with the database, so close the connection
//mysql_close($conn);

$resultCount = count($results);

//Generate bars
for ($i=0;$i<=$resultCount;$i++){
	imageFilledRectangle($img,20+(5*$i),($height-1)-($results[$i][1]*10),20+(5*$i)+3,$height,$blue);
}

//Generate y-scale
for ($j=0;$j<10;$j++){
	ImageString($img,1,8,$height-(10*$j), $j,$grey);
}
//Add titles
ImageString($img,1,20,0,"Google Rank for www.matthewbyrne.co.uk", $black);
ImageString($img,1,20,10, $results[0][0]." - ".$results[$resultCount-1][0],$black);

//Output graphic
header('Content-Type: image/png');
ImagePNG($img);
?>