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Yesterday I talked about creating some simple Flex elements in your application. Today I will introduce a new element called Script.

The Script element, if you haven't already guessed is used to run your application function and should be contained within the Application element. You can either put script inline like this.

<mx:Script>
// some code here
</mx:Script>

Or you can use the source attribute and link it with an external ActionScript source file.

Following on from my previous blog post about installing Flex on Windows I thought I would go through how to create an interface using mxml. When you create a Flex 3 project the first file you are given is called Main.mxml, which has the following content.

<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
 
</mx:Application>

This file is used to compile and run your Flex project and is the central starting point for all the rest of the compile process. This file controls your interface of your program. At first this file might look daunting, but there are lots of elements to select from and if you know CSS then you should be somewhat familiar with how elements are coloured, padded and positioned.

Flex is a powerful SDK that allows you to build Flash applications that can then be embedded into any web page. The SDK is that Flex uses quite large and covers a whole range of things from interface controls to data processing. To program in Flex you need to use ActionScript 3. What Flex creates as output is swf files, which can be run separately or embedded into a web page.

To get started you will need the Flex SDK. Download the Flex SDK 3 zip file and extract it into a directory where you can get to it. As an example, I put mine in C:\dev\flex_sdk_3.

I have talked about swapping values without a temporary third variable before, but there is another way to do this which doesn't make the code unreadable. This is by using the list() function in the following way.

$a = 1;
$b = 2;
list($a,$b) = array($b,$a);

This swaps the two values over. The good thing about this function is that you can swap any number of values over without the need to create lots of confusing temporary variables or using complicated looking bitwise operators. Take 4 variables.

$a = 1;
$b = 2;
$c = 3;
$d = 4;

These values can be entirely swapped using the list() function in the following way.

Note: This code has been written with WordPress 2.8 in mind. It won't work on versions prior to 2.6 and might have unpredictable results in later versions.

Drag and drop is a useful mechanism to do stuff and can turn a complicated set of buttons or drop down lists into a simple elegant solution.

Wordpress has lots of scripts built in, which do a lot of useful functions. However, they are not enabled by default, which means that in order to get your script to work you need to enable them.

The drag and drop functionality in Wordpress is provided by the Scriptaculous framework. To get Wordpress to include this in your page header just use the function wp_enqueue_script() with the parameter "scriptaculous-dragdrop".

Wordpress has an options table that developers can use when creating templates and plugins to store information that would otherwise have to be kept in a separate table or written to a file. Assuming the default table prefix of wp_ the options table is called wp_options.

Rather than allow developers to access this table directly, Wordpress has some functions that you can use to create and change options in that table.

To create an option and assign a null value to it use the add_option() function. The parameters are as follows:

There is an easy way to create a custom page for a particular page using Wordpress that doesn't involve adding custom page ID checking code. This might be useful if you want to remove certain aspects of the theme (like a side menu) just for that page. The way this is done is by using the Template Name tag in the following manner.

<?php
/**
 * Template Name: Page Template
 */
?>

Make a copy of your default page template in your theme directory and put this snippet of code at the top. You will now find that when you open the page to edit it there is a section called Page Template. This contains a drop down list of all of the templates available, including the default. You can create multiple page templates by just changing the value of the Template Name tag.

NOTE: This bit of code is potentially very dangerous and should NOT be uploaded to your web host. I only use this function on my localhost to quickly check that a snippet of code works.

If you want to quickly run some PHP code, and don't want to have to go through creating a file just to see the outcome of a simple calculation is then this snippet might be of some use to you.

It works by taking the contents of the textarea and creating a file with the filename of 'tempcodefile.php', which contains that code. The created file is then included in order to run the code, the output of which is displayed at the top of the screen.

Yesterday I wrote two posts about CodeSniffer and a common warning that I couldn't find any decent documentation on. I thought that today I would go over something that I also had trouble finding out about, this is the file doc error. When you run CodeSniffer on a class you might find the following error being produced.

In my last post I talked about the PHP CodeSniffer, so today I thought I would solve a common problem that doesn't seem to have any documentation. Whilst correcting a class file I had there was this one warning that just wouldn't go away.

FILE: myclass.php
--------------------------------------------------------------------------------
FOUND 0 ERROR(S) AND 1 WARNING(S) AFFECTING 1 LINE(S)
--------------------------------------------------------------------------------
 11 | WARNING | PHP version not specified
--------------------------------------------------------------------------------

There is no documentation (that I could find) on the CodeSniffer site about how to solve this, so I dove into the source files for the CodeSniffer extension and found this line.