<?php
/**
* @package Habari
*
*/
/**
* Habari Stack Class
*
* This class allows Habari to accumulate a group of unique values that
* can be output using a specific formatting string.
* This is useful for collecting a set of unique javascript references to output
* and then insert them at a specific point on the page.
*
* <code>
* // Add jquery to the javascript stack:
* Stack::add( 'template_header_javascript', Site::get_url('scripts') . '/jquery.js', 'jquery' );
*
* // Add stylesheet to theme_stylesheet stack with media type
* Stack::add( 'template_stylesheet', array( Site::get_url('theme') . '/style.css', 'screen' ), 'style' );
*
* // Output the javascript stack:
* Stack::out( 'template_header_javascript', '<script src="%s" type="text/javascript"></script>' );
*
* // Output the theme_stylesheet stack:
* Stack::out( 'template_stylesheet', '<link rel="stylesheet" type="text/css" href="%s" media="%s">' );
* </code>
*
*/
class Stack
{
private static $stacks = array();
private static $stack_sort = array();
private static $sorting;
/**
* Private constructor for Stack.
* Stack objects should only be created using the static
* method Static::create_stack(), or one of the methods that
* adds a value directly to a stack. This prevents multiple Stack
* objects from being created with the same name.
*
* @param mixed $input An array or ArrayObject to create the stack from.
* @return array The created stack
*/
private function __construct( $input )
{
parent::__construct( $input );
}
/**
* Retreive a named stack instance
* @param string $stack_name The name of the stack to return
* @return Stack The requested stack
**/
public static function get_named_stack( $stack_name )
{
if ( isset( self::$stacks[$stack_name] ) ) {
return self::$stacks[$stack_name];
}
else {
return self::create_stack( $stack_name );
}
}
/**
* Check for the existence of a given stack item.
*
* @param string $stack_name The name of the stack in which to check.
* @param string $value The value to check for.
* @return boolean true if the item exists, false otherwise.
*/
public static function has ( $stack_name, $value_name )
{
// get the stack
$stack = self::get_named_stack( $stack_name );
if ( isset( $stack[ $value_name ] ) ) {
return true;
}
else {
return false;
}
}
/**
* Get a single item from a given stack.
*
* @param string $stack_name The name of the stack to fetch an item from.
* @param string $value The item to fetch.
* @param mixed $default_value The default value to return if the item does not exist in the stack.
* @return mixed The item, or $default_value if it does not exist.
*/
public static function get_item ( $stack_name, $value_name, $default_value = null )
{
// get the stack
$stack = self::get_named_stack( $stack_name );
if ( isset( $stack[ $value_name ] ) ) {
return $stack[ $value_name ];
}
else {
return $default_value;
}
}
/**
* Creates and retreives a named stack instance
* @param string $stack_name The name of the stack to create and return
* @return array The created stack
**/
public static function create_stack( $stack_name )
{
if ( empty( self::$stacks[$stack_name] ) ) {
$stack = array();
self::$stacks[$stack_name] = $stack;
self::$stack_sort[$stack_name] = array();
}
return self::$stacks[$stack_name];
}
/**
* Add a value to a stack
* @param string $stack_name The name of the stack
* @param mixed $value The value to add
* @param string $value_name The name of the value to add
* @param string $after The name of the stack element to insert this new element after
* @return array The stack that was added to
**/
public static function add( $stack_name, $value, $value_name = null, $after = null )
{
$stack = self::get_named_stack( $stack_name );
$value_name = $value_name ? $value_name : md5( serialize( $value ) );
if ( !is_null( $after ) ) {
if ( !is_array( $after ) ) {
$after = array( $after );
}
foreach ( $after as $a ) {
if ( !isset( self::$stack_sort[$stack_name] ) ) {
self::$stack_sort[$stack_name] = array();
}
if ( !isset( self::$stack_sort[$stack_name][$a] ) ) {
self::$stack_sort[$stack_name][$a] = array();
}
self::$stack_sort[$stack_name][$a][$value_name] = $value_name;
}
}
$stack[$value_name] = $value;
self::$stacks[$stack_name] = $stack;
return $stack;
}
/**
* Remove a value to a stack
* @param string $stack_name The name of the stack
* @param string $value_name The name of the value to remove
* @return array The rest of the stack, post-remove
**/
public static function remove( $stack_name, $value_name )
{
$stack = self::get_named_stack( $stack_name );
if ( isset( $stack[$value_name] ) ) {
unset( $stack[$value_name] );
}
self::$stacks[$stack_name] = $stack;
return $stack;
}
public static function get_sorted_stack( $stack_name )
{
self::$sorting = $stack_name;
$stack = self::get_named_stack( $stack_name );
uksort( $stack, array( 'Stack', 'sort_stack_cmp' ) );
return $stack;
}
public static function sort_stack_cmp( $a, $b )
{
$aa = isset( self::$stack_sort[self::$sorting][$a] ) ? self::$stack_sort[self::$sorting][$a] : array();
$ba = isset( self::$stack_sort[self::$sorting][$b] ) ? self::$stack_sort[self::$sorting][$b] : array();
$acb = isset( $aa[$b] );
$bca = isset( $ba[$a] );
$ac = count( $aa );
$bc = count( $ba );
if ( ( $acb && $bca ) || !( $acb || $bca ) ) {
if ( $ac == $bc ) {
// they are equal in 'bias', so go with the order in which they were added.
return 1;
}
return $ac > $bc ? -1 : 1;
}
elseif ( $acb ) {
return -1;
}
elseif ( $bca ) {
return 1;
}
}
/**
* Returns all of the values of the stack
* @param string $stack_name The name of the stack to output
* @param mixed $format A printf-style formatting string or callback used to output each stack element
**/
public static function get( $stack_name, $format = null )
{
$out = '';
$stack = self::get_sorted_stack( $stack_name );
$stack = Plugins::filter( 'stack_out', $stack, $stack_name, $format );
foreach ( $stack as $element ) {
if ( is_callable( $format ) ) {
$out.= call_user_func_array( $format, (array) $element );
}
elseif ( is_string( $format ) ) {
$out .= vsprintf( $format, (array) $element );
}
else {
$out.= $element;
}
}
return $out;
}
/**
* Outputs all of the values of the stack
* @param string $stack_name The name of the stack to output
* @param mixed $format A printf-style formatting string or callback used to output each stack element
**/
public static function out( $stack_name, $format = null )
{
echo self::get( $stack_name, $format );
}
/**
* A callback for Stack::get() that outputs scripts as reference or inline depending on their content
*
* @param string $element The script element in the stack
* @return string The resulting script tag
*/
public static function scripts( $element )
{
if ( ( strpos( $element, 'http://' ) === 0 || strpos( $element, 'https://' ) === 0 ) && strpos( $element, "\n" ) === false ) {
$output = sprintf( '<script src="%s" type="text/javascript"></script>'."\r\n", $element );
}
else {
$output = sprintf( '<script type="text/javascript">%s</script>'."\r\n", $element );
}
return $output;
}
/**
* A callback for Stack::get() that outputs styles as link or inline style tags depending on their content
*
* @param string $element The style element in the stack
* @param string $typename The media disposition of the content
* @return string The resulting style or link tag
*/
public static function styles( $element, $typename )
{
if ( ( strpos( $element, 'http://' ) === 0 || strpos( $element, 'https://' ) === 0 ) && strpos( $element, "\n" ) === false ) {
$output = sprintf( '<link rel="stylesheet" type="text/css" href="%s" media="%s">'."\r\n", $element, $typename );
}
else {
$output = sprintf( '<style type="text/css" media="%s">%s</style>'."\r\n", $typename, $element );
}
return $output;
}
}
?>