PHPでフラッシュを実現する簡単なユーティリティ

flash.php

<?php

/**
 * This is alias of the flash::next() for conbinience.
 * @param $class
 * @param $content
 */
function flash($class, $content) {
	flash::next($class, $content);
}

/**
 * This class is simply notification function.
 * @author yuka2py
 */
class flash
{
	static private $_notice_class_name = 'notification';
	static private $_now;
	static private $_session_key = '__flash_values__';
	
	/**
	 * Initilizing flash variables.
	 * Must be call before using.
	 */
	static public function init($notice_class_name='notification') {
		if (!isset($_SESSION)) {
			session_start();
		}
		self::$_now = (array) (empty($_SESSION[self::$_session_key]) ? array() : $_SESSION[self::$_session_key]);
		unset($_SESSION[self::$_session_key]);
		$_SESSION[self::$_session_key] = array();
		self::$_notice_class_name = $notice_class_name;
	}

	/**
	 * Get flash message.
	 * @return mixed
	 * @param string $class
	 * @param mixed $default  Use this value if not set $class in flash.
	 */
	static public function get($class, $default=null) {
		if (isset($_SESSION[self::$_session_key][$class])) {
			$res = $_SESSION[self::$_session_key][$class];
		} else if (isset(self::$_now[$class])) {
			$res = self::$_now[$class];
		} else {
			$res = $default;
		}
		return $res;
	}

	/**
	 * Get all registered all flash message.
	 * @return array
	 */
	static public function get_all() {
		return array_merge($_SESSION[self::$_session_key], self::$_now);
	}

	/**
	 * Remove flash message. and returns poped value.
	 * @return mixed
	 * @param string $class
	 * @param mixed $default  Use this value if not set $class in flash.
	 */
	static public function pop($class, $default=null) {
		if (isset($_SESSION[self::$_session_key][$class])) {
			$res = $_SESSION[self::$_session_key][$class];
			unset($_SESSION[self::$_session_key][$class]);
		} else if (isset(self::$_now[$class])) {
			$res = self::$_now[$class];
			unset(self::$_now[$class]);
		} else {
			$res = $default;
		}
		return $res;
	}

	/**
	 * Remove all flash message. and returns poped values.
	 * @return mixed
	 * @param string $class
	 * @param mixed $default  Use this value if not set $class in flash.
	 */
	static public function pop_all() {
		$all = array_merge($_SESSION[self::$_session_key], self::$_now);
		$_SESSION[self::$_session_key] = array();
		self::$_now = array();
		return $all;
	}

	/**
	 * Register flash message for current or next session.
	 * Note: If already exists same class name value as now context then remove it.
	 * @param string $class
	 * @param string $content
	 */
	static public function next($class, $message) {
		$_SESSION[self::$_session_key][$class] = $message;
		unset(self::$_now[$class]);
	}

	/**
	 * Register flash message for current session.
	 * Note: If already exists same class name value as next context then remove it.
	 * @param string $class
	 * @param string $content
	 */
	static public function now($class, $message) {
		self::$_now[$class] = $message;
		unset($_SESSION[self::$_session_key][$class]);
	}

	/**
	 * Print all flash message with html tag, if registered it.
	 * If no flash, then does not printetd and return false.
	 * When printed flash, returns true.
	 * Notice: Skip print if class name starts with '_'.
	 * @return boolean
	 * @param boolean $nl2br
	 * @param string $addtional_class_name
	 */
	static public function print_notice($nl2br=true, $addtional_class_name=null) {
		$flashes = self::get_all();
		$printed = false;
		foreach ($flashes as $class => $message) {
			if (strpos($class, '_') !== 0) {
				self::pop($class);
				$class_names = (array) self::$_notice_class_name;
				$class_names[] = $class;
				if ($addtional_class_name)
					$class_names[] = $addtional_class_name;
				if ($nl2br)
					$message = nl2br($message);
				echo sprintf('<div class="%s">%s</div>', implode(' ', $class_names), $message);
				$printed = true;
			}
		}
		return $printed;
	}

	/**
	 * notice で使用されるデフォルトのクラス名を変更する。
	 * @param string $class_name
	 */
	static public function set_notice_class_name($class_name) {
		self::$_notice_class_name = $class_name;
	}
}