Feature-wise not much has changed since the Beta and Release Candidate cycles but the code has been thoroughly tested and improved where possible. If you’re planning on building a PHP website, give Swiftlet a try.

I moved the project page and documentation away from Google Code, if you go to swiftlet.org you’ll find the new page. It’s powered by a documentation system that I custom coded (dubbed Pintail). If there is any interest I will release the code behind it as Open-Source as well.

One of the most important recently added features is the plug-in installer. It checks for compatibility with the core code and creates and populates database tables with a click of the mouse. Plug-ins that don’t require a database connection don’t need to be installed; they’re plug-and-play (and Swiftlet runs fine without a database).

I also added plug-ins to handle user sessions and authorization. This should make it easy to create a website that requires a login system.

Download: code.google.com/p/swiftlet/downloads/list

It’s targeted at developers who want to built simple websites that don’t require large and complex frameworks, but do want a solid base to work from. Swiftlet provides basic security features such as user input sanitizing, is highly extensible thanks to the deeply integrated hook system, completely Object Oriented and separates logic from design (MVC).

Even the most basic features such as connecting to a database and output buffering are implemented as plug-ins. This means they can be modified, extended and removed without hacking into the core code.

Website: http://swiftlet.org

If you ever want to combine frameworks you may discover that they use similar names for some variables and functions. This can lead to unexpected output and security holes. If you’re planning on writing a framework of your own, consider wrapping it in an object.

In PHP5 it’s possible to pass objects by reference which means you can send an instance of a class to another class. This way you can nest classes and access the parent.

core.php:

class core
{
    public
        $var = 'This is a global variable.';
 
    const
        CONST_VAR = 'This is a constant.';
 
    // This function is executed when core is initialized.
    function __construct()
    {
        include('classes/foo.php');
 
        $this->foo = new foo($this);
    }
 
    // All the main functions go here.
}

foo.php:

class foo
{
    private $core;
 
    function __construct($core)
    {
        // Reference to the core object.
        $this->core = $core;
    }
 
    function hello_world()
    {
        echo $this->core->var;
    }
}

In this example “core” is the site’s main object containing global variables and functions. When we create an instance of class “foo”, we send a reference to the core object (“$this”) as a parameter. On a regular page the classes, variables and function can be accessed like this:

page.php

include('classes/core.php');
 
$core = new core();
 
echo $core->var; // output: This is a global variable.
echo core::CONST_VAR; // output: This is a constant.
 
$core->foo->hello_world(); // output: This is a global variable.

This way there is only one variable in the global scope: $core. Another advantage is that all variables declared in core are global and accessible throughout the whole program.

1. Drop braces

Braces aren’t required in control structures with only one expression. Sometimes it makes sense to drop them. It’s very easy to make mistakes if you ever add code to the structure, I recommend only to do this when the expression is short and fits on a single line.

Long:

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if ( $module == TRUE )
{
    load($module);
}
else
{
    error('No module');
}

Short:

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if ( $module ) load($module);
else           error('No module');

2. Use ternary operators

The above example can be made even more compact using ternary operators:

$module ? load($module) : error('No module');

3. Use “OR” instead of “IF”

“OR” is the same as “or” and ”||”.

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if ( $foo )
{
   echo $foo;
}
else
{
   echo $bar;
}

Short:

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echo $foo || $bar;

4. Don’t compare variables to booleans

“if ( $foo == TRUE )” is the same as “if ( $foo )”. This shortcut can make your life as a programmer much easier:

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function has_value($var)
{
    if ( $var == TRUE )
    {
        return TRUE;
    }
    else
    {
        return FALSE;
    }
}

Short:

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function has_value($var)
{
    return ( bool ) $var;
}

5. Use default values for variables

It’s usually a good idea to define important variables at the beginning of your script, instead of inside control structures (this could result in undefined variables later on). Another advantage is that you can often save an entire else-block as demonstrated in this example:

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if ( $foo > 3 )
{
    $message = '$foo is greater then 3.';
}
else
{
    $message = '$foo is lower than or equal to 3.';
}

Short:

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$message = '$foo is lower than or equal to 3.';
 
if ( $foo > 3 )
{
    $message = '$foo is greater then 3.';
}

6. Assign variables inside conditions

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$contents = file_get_contents($file);
 
if ( $contents )
{
    echo $contents;
}

Short:

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if ( $contents = file_get_contents($file) )
{
    echo $contents;
}

7. Group variable declarations

Instead of prefixing every single variable declaration in a class with “public”, “protected” or “private” keywords, group them:

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class db
{
    public $query;
    public $result;
    public $tables;

Short:

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class db
{
    public
        $query,
        $result,
        $tables
        ;

Something similar can be done with regular variable declarations if they need to assign them the same value:

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$foo    = TRUE;
$bar    = TRUE;
$foobar = TRUE;

Short:

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$foo    =
$bar    =
$foobar = TRUE;

8. Merge arrays instead of assigning individual keys

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$items = array('item 1', 'item 2');
 
$items[] = 'item 3';
$items[] = 'item 4';
$items[] = 'item 5';

Short:

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$items = array('item 1', 'item 2');
 
$items = array_merge($items, array(
    'item 3',
    'item 4',
    'item 5'
    ));

Even shorter:

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$items = array('item 1', 'item 2');
 
$items += array(
    'item 3',
    'item 4',
    'item 5'
    );

That’s it! Please share this post if you found it useful.